I.B.-R9

OPERATION AND INSTALLATION

MANUAL

INSTRUCTION MANUAL BOOK NO. 99-0145-40HSE HS123/145 kV- 40 kA - 2000/3000/3125 A

DUAL RATED ANSI / IEC GAS CIRCUIT BREAKER

REVISION 9, MARCH 2011

Table of Contents PREFACE................................................................................................................................................................ iii

CHAPTER 1. SAFETY............................................................................................................................................1 1.1 INTRODUCTION ............................................................................................................................................1 1.2 GENERAL SAFETY .......................................................................................................................................1 1.3 SPECIFIC SAFETY........................................................................................................................................1 1.4 SULFUR-HEXAFLUORIDE (SF6) GAS ........................................................................................................2 1.5 sERVICE SAFETY..........................................................................................................................................2

CHAPTER 2. GENERAL INFORMATION.............................................................................................................0 2.1 DESCRIPTION OF BREAKER......................................................................................................................0 2.2 GENERAL CONTROL INFORMATION........................................................................................................5 2.3 BREAKER OPERATION................................................................................................................................7

CHAPTER 3. INSTALLATION................................................................................................................................1 3.1 PACKING SHIPPING and RECEIVING........................................................................................................1 3.2 TOOLS AND TESTING EQUIPMENT..........................................................................................................1 3.3 STORAGE.......................................................................................................................................................3 3.4 ASSEMBLY INFORMATION .........................................................................................................................3 3.5 INSTALLATION TESTING.............................................................................................................................5 3.6 Installation & ASSEMBLY Check-List..........................................................................................................9

CHAPTER 4. SF6 GAS SYSTEM...........................................................................................................................1 4.1 GENERAL INFORMATION ...........................................................................................................................1 4.2.A SF6 TEMPERATURE COMPENSATED PRESSURE GAUGE ..............................................................1 4.3A Filling with SF6 gas .......................................................................................................................................3 4.4A SF6 LEAK RATE AND LEAK DETECTION...............................................................................................4 4.5A SF6 TEMPERATURE COMPENSATED GAS MONITORING SYSTEM ................................................5 4.2.B TEMPERATURE COMPENSATED PRESSURE SWITCH ...................................................................6 4.3B Filling with SF6 gas ......................................................................................................................................7 4.4B SF6 LEAK RATE AND LEAK DETECTION...............................................................................................8 4.5B SF6 TEMPERATURE COMPENSATED GAS MONITORING SYSTEM ................................................9 4.6 TESTING SF6 SYSTEM PRESSURE.........................................................................................................10 4.7 OPTIONAL PRESSURE SYSTEM - INDIVIDUAL PHASE MONITORING.............................................12 4.8 Pulling Vacuum .............................................................................................................................................12

4.9 O - RingS AND GASKETS Installation.......................................................................................................12 4.10 Swagelok Gas seal system........................................................................................................................13 4.11 Rupture Disk................................................................................................................................................14 4.12 Crankbox rotating o-ring seals ...................................................................................................................15

CHAPTER 5. MAINTENANCE..............................................................................................................................1 5.1 SAFETY NOTE...............................................................................................................................................1 5.2 REPLACEMENT PARTS...............................................................................................................................1 5.3 GENERAL NOTES.........................................................................................................................................1 5.4 Inspection and Maintenance Schedule .........................................................................................................2

APPENDIX................................................................................................................................................................1 Appendix 1. Torque Value Chart.........................................................................................................................1 Appendix 2. Operation Travel Curves.................................................................................................................2

REVISION HISTORY.............................................................................................................................................14

PREFACE

This manual covers the installation and operation of the HVB AE Power Systems, Inc. 123/145kV/40kA gang operated puffer circuit breaker. These instructions should be reviewed thoroughly to insure proper understanding prior to performing any work on the equipment.

Prior to performing any work on the circuit breaker, be absolutely sure to review the “SAFETY” section of this manual and insure that all personnel scheduled to work on the equipment are familiar with the recommendations of that section.

The illustrations and information provided in this manual are designed to cover the normal customer requirements. However, this manual may not cover some customer-required special items.

If, for any reason, a problem were to occur which is not covered by this manual, HVB AE Power Systems, Inc. would request that the following information be available:

Customer/Company Name

Job Site Name (substation)

Circuit Breaker Rating (123/145kV/40kA)

Circuit Breaker Serial Number (main nameplate)

To contact HVB, use the following contact information:

HVB AE Power Systems, Inc.

7250 McGinnis Ferry Road

Suwanee, GA 30024

United States of America

Phone: (770) 495-1755

Toll Free: (866) 362-0798

Fax: (770) 623-9214

CHAPTER 1. SAFETY

1.1 INTRODUCTION

To the extent required, the products described herein meet applicable ANSI, IEC, IEEE and NEMA standards as of the time of manufacture but no such assurance is given with respect to local codes and ordinances because they vary greatly.

The term "breaker" includes all equipment mounted on the circuit breaker foundation.

NOTE: These instructions do not purport to cover all details or variations in equipment nor to provide for every possible contingency to be met in connection with installation, operation or maintenance. Should further information be desired or should a particular problem arise which is not covered sufficiently for the purchaser's purposes, the matter should be referred to HVB AE Power Systems, Inc.

Each user is responsible for instructing all personnel associated with his equipment on all safety precautions that must be observed.

The following are recommendations to be considered in a user's safety program. These recommendations are not intended to supplement the user's responsibility for devising a complete safety program and shall not be considered as such. They are suggestions to cover the more important aspects of personnel safety related to circuit breakers. HVB AE Power Systems, Inc. neither condones nor assumes any responsibility for user practices that deviate from these recommendations.

1.2 GENERAL SAFETY

All personnel associated with installation, operation and maintenance of power circuit breakers should be thoroughly instructed and supervised regarding power equipment in general and also the particular model of equipment with which they are working. Instruction books and service advisories should be closely studied and followed.

Maintenance programs must be well planned and carried out consistent with both customer experience and manufacturer's recommendations, including service advisories and instruction books. Good maintenance is essential to breaker reliability and safety.

Local environment and breaker application must be considered in such programs, including such variables as ambient temperatures, actual continuous current, number of operations, type of interrupting duty, and any unusual local condition, such as corrosive atmosphere or major insect problems.

1.3 SPECIFIC SAFETY

DO NOT work on an energized circuit breaker. If work has to be performed on the breaker, take it out of service, open the disconnect switches at each side of the breaker, then close the breaker and ground each phase.

DO NOT work on any part of the de-energized breaker until all control and heater power has been disconnected.

CHAPTER 1 SAFETY

DO NOT disassemble any portion of the gas system of any circuit breaker until system pressure has been reduced to zero psig by opening the appropriate drain valves. When the gas pressure has been reduced to zero, cautiously remove covers, tubes, fittings, etc.

If SF6 is to be added to a pressurized system, measures should be taken to protect personnel against sudden gas release. Upon completion of adding gas to the breaker, the fill valve should be closed. The pressure should then be relieved between the source and the fill valve prior to removal of transfer tool/filter drier.

Particular care must be exercised to keep personnel clear of all spring-charged mechanisms. Only skilled and knowledgeable personnel capable of releasing each spring load in a controlled manner must service the breaker. Information on construction of such mechanisms is provided in this instruction manual.

NOTE: This breaker is spring opened and spring closed. Always ensure that ALL springs are discharged before working on the breaker.

The gas breaker will hold line-to-ground voltage under positive SF6 pressure on an energized transmission line where no voltage disturbances are present. Under these conditions, the breaker should be de-energized by back-up protection breakers and isolated and removed from the system as a safety precaution.

If there is any evidence of deterioration of breaker dielectric capability, the breaker should be de-energized by back-up protection breakers and isolated from the systems by disconnect switches.

Operational tests and checks should be made on a breaker after maintenance and prior to returning to service to ensure that it is capable of operating properly. The extent of such tests and checks should be consistent with the level of maintenance performed.

1.4 SULFUR-HEXAFLUORIDE (SF6) GAS

SULFUR-HEXAFLUORIDE (SF6) gas in its natural state is a colorless, odorless, and tasteless gas with an extremely low order of toxicity. It is chemically and physiologically inert and non-flammable.

The SF6 gas is approximately 5.5 times heavier than air, and it will displace oxygen. Because of this, care should be taken when working with SF6 in an enclosed environment. Since it is colorless and odorless, care should be exercised when handling the gas to provide good ventilation. SF6 gas escaping into a closed room or pit will float at the lower levels and can cause a possible oxygen shortage.

The SF6 gas, when exposed to electrical arcing, may form toxic decomposition products. These may be evident as an unpleasant odor and a small amount of very fine powdery material found in the tank.

Before an SF6 tank is entered for maintenance the gas should be evacuated. The tank should then be cleaned thoroughly with equipment capable of removing very fine dust particles and then flushed with dry air to provide oxygen to the normal level.

When entering the tank, a respirator mask should be worn. Powder or dust found in the tank should be removed while wearing gloves. Hands, face, etc. should be carefully washed if they have been exposed to the powder.

1.5 SERVICE SAFETY

The information provided in this section is designed to give highlights of the information provided in this chapter. There are three simple and basic rules that will provide safety for anyone working on this type circuit breaker.

Disconnect AC and DC power supplies at the circuit breaker.

With the AC & DC removed from the circuit breaker no powered operation can be done either locally or remotely. This would prevent accidental operation of the breaker due to, someone pressing the local trip/close push buttons (optional) or remotely operating the breaker from the control system.

Turn the SF6 test valve to the test position.

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CHAPTER 1 SAFETY

With these valves in the test position the circuit breaker control circuits will be opened. The breaker would, in effect, be in a lockout status due to loss of gas pressure. This also precludes the possibility of someone restoring the AC & DC power and then operating the circuit breaker.

Note: Make sure the all springs are discharged.

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CHAPTER 2. GENERAL INFORMATION

2.1 DESCRIPTION OF BREAKER

The HVB 123/145kV/40kA (Figure 2.1) is a high performance dead tank gas circuit breaker. The breaker ratings are stated on the breaker nameplate. This breaker is a three-phase device rated to interrupt AC power systems. There is one interrupter assembly per phase, containing moving and stationary contacts, provided with a single break per phase.

The mechanism is of the stored energy type and is operated by an opening and two closing springs. An AC/DC motor charges the closing springs. The closing springs are used to close the breaker and at the same time to charge the opening spring.

Closing and opening operations are controlled electrically by the control switches on the breaker or by remote relaying. Mechanical handles are provided to manually close and open the breaker.

Electrical insulation is provided by SF6 gas charged to 75 psig at 20 °C (68 °F). The cast aluminum pressure vessels and both entrance bushings are filled with SF6 gas. A gauge monitors the gas pressure and a temperature compensated pressure switch. Due to the insulation being provided by the gas, the breaker should not be operated below the lock out pressure of 64 psig. The pressure switch and control system provide the lockout.

Bushing current transformers (BCT) are usually provided to monitor electrical current passing through the breaker. The BCT’s are mounted below the entrance bushings inside their own cover.

There is a control cabinet mounted to the frame and below the tanks. This cabinet contains the operating mechanism, interphase linkage, control system and the customer connections. This cabinet is heated to keep moisture from damaging the various devices.

Figure 2.1 HS 123/145 kV 40 kA Gas Circuit Breaker

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2.1.1 INTERRUPTER

Figure 2.2 shows the interrupter assembly. The single puffer-type interrupter is installed in a grounded tank filled with SF6 gas at a reference pressure of 75 psig at 20 °C (68 °F).

NUMBER DESCRIPTION NUMBER DESCRIPTION

1 Stationary Insulator 12 Moving Arc Contact

2 Bolt 13 Shield

3 Stationary Conductor 14 Inner Cylinder

4 Main Sliding Contact 15 Seal

5 Main Moving Contact 16 Seal

6 Interrupter Body 17 Support

7 Outer Cylinder 18 Teflon Shield

8 Stationary Arc Contact 19 Moving Conductor

9 Arc Contact Support 20 Actuation Rod

10 Teflon Nozzle 21 Moving Insulator

11 Teflon Cover 22 Support Plate

Figure 2.2 HS 123/145 kV 40 kA Interrupter

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2.1.2 PORCELAIN INSULATOR/CONDUCTOR/GAS TANK ASSEMBLY

Figure 2.3 shows the porcelain insulator / conductor assembly installed on each end of the interrupter tank.

Figure 2.3 Porcelain / Conductor assembly installed on Gas Tank

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2.1.3 MECHANISM SPRING-SPRING

The circuit breaker mechanism (Figures 2.4, 2.5) is made up of several assemblies including the charging system, closing spring, tripping linkage and auxiliary switches.

Figure 2.4 Mechanism side view (Breaker Closed / Spring Charged)

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Figure 2.5 Mechanism back view 2.1.3.1 Charging System and Closing Spring

The gear motor drives the charging mechanism that compresses the closing springs. The gear motor turns the gear train that rotates the charging gear. There are two pawls on the charging gear that turn the charging camshaft. There is a position switch that detects the position of the charging camshaft and controls the power to the motor. There are two drums on the camshaft that are attached to links that pull the closing springs to the charged position. The camshafts and drums compress the closing springs in 180° of rotation. The motor switch also performs the added function of not allowing the closing coil to operate until the motor has finished the charge cycle. The interrupter contacts do not move during this operation. This cycle takes less than 15 seconds.

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2.1.3.2 Closing Operation

To close the breaker, power is applied to the closing coil. The coil trips the closing latch releasing the closing spring to drive the breaker contacts closed through a cam. To close the breaker, the spring pulls the closing links causing the cam to compress the opening spring and close the interrupter contacts. Immediately upon the discharge of the closing spring the closing spring position switch detects that the spring has discharged then the motor is activated and starts the charging cycle.

2.1.3.3 Tripping Operation

To trip the breaker, power is applied to the trip coil. This coil trips the latch that is holding the breaker closed. This releases the opening spring that drives the contacts open with the dashpot controlling the shape of the stroke curve.

WARNING The breaker must never be operated in a low gas situation, below the 64 psig @ 20°C lockout pressure. This applies to both manual and electrical operation. The control system defeats electrical operation, there is no such safety on the mechanical trip and close devices. There are two reasons for not operating below this value.

1. The breaker has inadequate electrical insulating and arcing extinguishing properties below the lockout pressure.

2. The mechanism relies on the gas pressure for damping of its motion.

Operating below the lock out will result in mechanical damage to the breaker and can cause catastrophic damage to the breaker resulting in injury up to and including loss of life to personnel near the GCB.

(This note does not refer to slow opening and closing using the manual operating device on a de-energized breaker.)

2.1.4 INTERPHASE LINKAGE

The interphase linkage connects the mechanism to the three interrupters. This linkage is made up of a series of collinear shafts in the crank box. The mechanism controls the position of the interphase linkage through the main crank therefore controlling the interrupter position.

In the closing action the mechanism pushes on the main crank closing the interrupter contacts. In the opening action the mechanism pulls on the main crank opening the interrupter contacts.

The gas is sealed by rotating and stationary o-rings.

2.2 GENERAL CONTROL INFORMATION

2.2.1 INITIAL BREAKER WIRING 2.2.1.1 CONTROL/MECHANISM CABINET

The Control/Mechanism Cabinet will be referred to throughout this manual as the Control Cabinet although it contains both the control system and the mechanism. Bring the customer’s power leads directly into the control cabinet through the removable panel in the floor of the right side. Attach the leads to the appropriate terminal

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boards, per the wiring diagram. The trip coils, close coils, and auxiliary switches located on the mechanism are wired into the circuit as needed or terminated at a terminal block points.

2.2.1.2 CONTROL CIRCUITS

The control circuits of the breaker consist of the components necessary to energize the trip and close coils on the mechanism, sense the CLOSE / OPEN positions of the breaker, and prevent breaker operation if unsafe or unsatisfactory conditions exist.

The close or trip signals are normally input from the customer’s power control circuit, but may be input by a local push button or trip handle (optional) in the control cabinet. The trip handles should be for testing only.

2.2.1.3 CLOSING OPERATION

When the breaker is to be closed, a signal is impressed on the close circuit. Assuming the breaker is open in normal operational condition, the normal sequence of events is as follows:

1. The closing coil is energized.

2. The closing coil operates releasing the mechanical latches, allowing the closing springs to drive the interrupters to the closed position. The closing action also charges the opening spring.

3. The auxiliary switch operates.

a) Opening all the 52b contacts.

b) Close coil current is interrupted by one or more 52b contacts.

c) Closing all 52a contacts.

4. The 52Y relay is sealed in through its normally open contacts. This insures no additional close signals can be applied until this operation sequence is complete.

5. When the close signal is removed, the 52Y relay will be de-energized and the breaker will remain in the closed position.

6. Close operation is blocked while motor is running to charge the closing springs.

7. Close operation is also blocked when SF6 gas pressure is below certain level.

2.2.1.4 OPENING OPERATION

When the breaker is to be opened, a signal is impressed on either the trip #1 or trip #2 circuit. Assuming the breaker is closed and in normal operational condition, the normal sequence of events is as follows:

1. The opening coil is energized.

2. The opening coil operates releasing the mechanical latches, allowing the opening spring to drive the interrupters to the opened position.

3. The auxiliary switch operates

a) Opening all the 52a contacts. Open coil current is interrupted by one or more 52a contacts.

b) Closing all 52b contacts.

c) Open operation is blocked when SF6 gas pressure is below certain level.

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2.2.1.5 ADDITIONAL CONTROL FEATURES

Anti Pump (52Y)

The anti-pump system allows the closing signal to energize the closing coil only one time for each application of a close signal. This is accomplished by the 52Y relay that opens the close circuit after the breaker closes and keeps it open until the close signal is removed. On a trip-free operation the breaker will close then open and will remain open until the original close signal is removed.

An additional note of interest is that the spring charge control system also blocks the close function until the motor has finished. Therefore until the motor is finished the anti-pump relay is not the sole device that opens the close circuit.

2.3 BREAKER OPERATION

The operation of the circuit breaker is covered in the following paragraphs.

2.3.1 MECHANISM

This circuit breaker has a spring-spring mechanism to operate the interrupters.

2.3.2 ARC INTERRUPTION PRINCIPLE

The basic puffer breaker interrupter is shown in Figure 2.6, with an identical unit being used in each SF6 gas tank. The following sequences describe the Principle of Arc interruption:

Once the trip signal command is issued the insulated operating rod with the puffer cylinder will be pulled rapidly to the right as the mechanism operates to the open position.

The rapid movement of the cylinder will compress the SF6 from normal pressure to approximately 150 psi. The gas is prevented from escaping the cylinder by the puffer piston and Teflon nozzle.

The cylinder will continue to move causing increasing gas pressure. The main current path will remain between the arcing contacts after the main contacts are separated.

Further movement of the cylinder will part the contacts and the arc will be established between the arcing contacts (inside of insulating nozzle).

The blast releasing exhaust ports, at the nozzle and at the other end of the hollow driving shaft, direct the gas pressure to the established arc.

The axial nature of the gas blast is effective in stretching and cooling the arc. Total blast time varies from 16 to 25 milliseconds, depending on current being interrupted.

Full interrupting capacity is provided with gas densities corresponding to gas pressures from 64 to 75 psig at 20 °C.

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Figure 2.6 Principle of Arc Interruption

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CHAPTER 3. INSTALLATION

3.1 PACKING SHIPPING AND RECEIVING

Packaging has been planned to support the field erection sequence and provide easy identification of the components.

The breaker is shipped from the factory on one truck ready for installation. All parts necessary to assemble the breaker are included as well as additional items required under the purchase contract.

The shipment is broken down into the following main items (crucial to the proper assembly and installation of the circuit breaker):

GCB Assembly

Parts Box

Upon arrival, the entire shipment should be checked for damages or shortages. Shipping papers, including a packing list along with an instruction manual and a full set of prints, will be in a plastic envelope in the pocket inside of cabinet door. Additionally, a second copy of this packing list can be found in the parts box normally shipped with the circuit breaker.

NOTE: It is especially important that any damage incurred during shipping, be reported as soon as possible to HVB AE Power Systems, Inc. to assure early delivery of replacement parts.

3.2 TOOLS AND TESTING EQUIPMENT

Items actually sent with every shipment may vary in quantity and appearance according to the requirements of the particular unit or customers contract.

3.2.1 TOOLS

Most of the work on this circuit breaker can be accomplished using standard tools. The hardware on the circuit breaker are normally metric. The gas piping system is US standard.

1. Special tools are normally required in the purchase contract and shipped with the circuit breaker. One set of tools is supplied with every five (5) circuit breakers or for every different substation on an order. Your purchase contract can, of course, affect the amount of tools shipped. The following is a list of tools normally shipped.

a. Grease – Gleitmo 805 K

b. Grease - Hitalube 280

c. SF6 Gas Transfer Tool

d. Maintenance Operating Screw Assembly, this screw requires a 1 1/8 wrench to operate (wrench is not supplied).

e. Adapter - GCB Tank to SF6 bottle

CHAPTER 3 INSTALLATION

f. Manual charging closing springs device. This device is used to charge the closing springs when the motor power is temporarily lost (emergency case).

The device is permanently installed on mechanism plate (above the motor) as shown in Figure 3.1.

Figure 3.1. Manual Charging of Closing Springs Device Instruction how to operate it:

To charge the closing springs, use a 19 mm socket and a RATCHET WRENCH (THE MOTOR POWER MUST BE DISCONNECTED) and crank clockwise (viewing from left) until is heard a click. At this moment STOP cranking, the closing springs are charged.

g. DO NOT CRANK AFTER THE CHARGING CYCLE IS COMPLETED.

2. The following list is intended to include the common METRIC hand tools required to maintain this circuit breaker. These tools are not supplied with a circuit breaker except as a special order. Metric tools are not considered “special tools” as they are required for more equipment than this circuit breaker.

a. Sockets

i. 1/2 inch drive - sizes M10, M13, M17, M19, M30

ii. 3/8 inch drive - sizes M6 through M26

b. Wrenches

i. Combination - sizes M10, M13, M17, M19

c. Scale

i. 150 millimeters - approximately 6 inch

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ii. 1000 Millimeters - approximately 3 feet

d. Allen Wrenches

i. Sizes up to M10

3.2.2 TESTING EQUIPMENT

Certain equipment should be available for installation and future maintenance testing of the circuit breaker.

1. Gas handling equipment with a vacuum pump

2. Vacuum gauge capable of reading 1mm of mercury or 1000 microns

3. SF6 Leak Detector

4. Electrolytic Hygrometer - (SF6 Moisture Analyzer)

5. Digital Micro-ohmmeter

6. Megger - 1000 Volt

7. Leak - Tec or equal for gas leak testing

8. Ductor - 100 Amp

9. Motion Analyzer

10. Thermometer

11. Calculator

12. Indicating flashlight with leads

3.3 STORAGE

3.3.1 Breaker Assembly

1. Check to be sure each pole has a slight positive pressure by opening the fill valve. If the breaker shows zero pressure pull vacuum before filling with SF6, see Chapter 4 for method. For storage set the gas pressure to 5 to 15 psig the low of 5 is to ensure that the interrupters and tank internals stay clean and dry. Storage pressures above 15 psig are not necessary and constitute a safety hazard in case the bushings are damaged in storage. Check at monthly intervals for positive pressure.

2. Connect all heaters to a proper voltage source. Power leads should enter the control cabinet through the floor by removing a bolt in the floor. Connection should be made at the heater fuse to supply heater power. DO NOT LEAVE DOORS PARTIALLY OPEN.

3.3.2 All Parts Boxes

These parts should be kept dry at all times and stored inside a building, if possible. If unable to store inside, keep off the ground and out of standing water. Cover with canvas or heavy plastic tarpaulin.

3.4 ASSEMBLY INFORMATION

3.4.1 PRELIMINARY INFORMATION

The three poles of the 123/145kV gas breaker are identical on the standard breaker.

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These instructions are supplemented by a set of drawings supplied with the breaker. The types of drawings furnished include the outline, assembly, electrical elementary, electrical device and ratings list. These drawings, along with any others that the customer may have requested, are placed with the breaker instruction book, and stored in a special pocket on the electrical control house door.

The breaker will be located on a reasonably level foundation and properly shimmed and secured with anchor bolts. The foundation is to provide uniform support to the frame and SF6 gas tanks and to not add any stress. Space must be provided for opening the control house doors and making the necessary control connections.

Space should be allowed at the end of each pole to allow for possible maintenance of the internal parts of the breaker. Should flood conditions exist, the foundation must be sufficiently high to assure the control house is above the high water level.

All standard safety practices, codes and ordinances should be followed during erection and operation of the breaker.

Prior to any work being done on the subject breaker, the section of this manual on safety should be reviewed and understood thoroughly.

CAUTION When working on the gas system open fill valves even though the gauge indicates zero pressure. To ensure that you do not open a vessel that is under pressure!

DO NOT open interrupter tank when there is a chance of water, dust, or other contaminants entering the vessel. Internal cleanliness is essential to the successful operation of the circuit breaker. The tanks are charged to a positive pressure with SF6 gas when delivered. This pressure should be kept in mind when beginning installation.

SAFETY Each user, contractor, or installer is responsible for instructing all personnel associated with this equipment on all safety precautions that must be observed. Read the SAFETY SECTION in this Instruction Manual.

3.4.2 GENERAL ASSEMBLY PROCEDURES

1. The foundation should be of sufficient strength stability to prevent any stress in the SF6 tank due to ground movement. Foundation to be level within 0.25 inch within support areas. For bolt pattern and loads see breaker outline drawing. Sling the breaker assembly using the four lifting plates. Use equal length cables that are 8 feet or longer.

2. Bolt the breaker in place using heavy washers attached to the two ground pads on the support beams. If necessary, shim between support plates and foundation to insure a direct transmission of loads to the foundation and prevent stressing the SF6 tanks.

3. Install all ground leads to the frame ground pads as show on customer drawing. Connect the ground strap at the bottom of the control cabinet to the ground grid.

4. Each pole assembly is factory charged to approximately 5 psig with SF6. Therefore it is not necessary to pull vacuum on the breaker, simply fill with dry SF6. Approximately 47 lbs of gas will fill the GCB. See Chapter 4 for SF6 handling.

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3.5 INSTALLATION TESTING

3.5.1 GENERAL

Please see the next section for the Installation Check-List. Timing tests are optional and are not required. Be sure to follow all manufacturers instructions when using the specialized equipment required in this section.

1. Fill out owner and circuit breaker information on the first page of the Installation Check-List.

2. Perform the inspections on the first page.

3. SF6 Gas System

a. Record ambient air temperature

b. Record the gauge pressure. The correction factor is calculated from the instruction books Temperature vs. Gas Pressure chart, see chapter 4.

c. Switch checks. Record the gauge readings for both ON (decreasing pressure) and RESET (increasing pressure). Use the correction factor to normalize the pressure to a room temp value. Confirm that the corrected values are within the tolerances in the chart.

d. Leak check the gas system

e. Moisture analysis is recommended. When using gas provided by HVB the gas is guaranteed by the supplier to have a moisture level below 150 ppm, therefore testing moisture with HVB gas is optional.

3.5.2 MECHANICAL TESTS

3.5.2.1 External stroke and wipe measurement, (Figure 3.2)

1. Connect an indicating light, flashlight with leads, to the three poles of the breaker to determine when the contacts close.

2. Remove the cover on the back of the opening spring and insert the manual charge screw into the threads. Tighten the screw until it is hand tight. Record the length of threads (A) that is sticking outside the spring tube. Using a wrench, tighten the screw into the spring tube, ( this will cause the contacts to move) until the first light lights. Write that value (B) in the column “Contact” for the appropriate pole. Continue for each of the three lights.

3. Continue to tight the screw. Watch for the trip latch to set. STOP operating the manual screw when the latch sets. Back off the manual screw to allow the latch to carry the spring load. You will feel the screw become easier to turn as the latch takes the load. The breaker is now in the closed position. Before making the final measurement (C) be sure that the screw is hand tight against the open spring. Calculate the External Stroke (A-C) and Wipes (B-C).

4. Open the breaker by tightening the screw against the spring load again. Press and hold the red open button to clear the trip latch, then open the breaker by unscrewing the manual operating screw. After one turn the latch will have cleared and the open button can be released.

5. Remove screw and install back the open spring cover.

6. Calculate the Delta (Phase to Phase) by calculating the difference between the max and min values of wipe.

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3.5.2.2 Circuit breaker operational test

This test can be performed with or without motion analyzing equipment. Performing a motion test with analyzing equipment is optional. If the transducer is attached to the same location as the external stroke was measured the transfer function is: 97 mm external stroke / 154 mm internal = .63

1. Test for the close, C, and open, O, function by pressing the open and close electrical buttons. If equipped for dual trip, test both.

2. To test C-O & Anti Pump the breaker must be in the open position. Press both open and close buttons simultaneously. The breaker should close then immediately open with no delay then lockout the close function as long as the close button is held in. To properly test hold the close button until after the motor has stopped charging.

3. For the O-C test the breaker must be in the closed position. Press and release the open button. The breaker should open. Then press the close button and the breaker should close.

4. SF6 Lockout Function. Before performing this test, check the schematic to see if the control circuit is designed to simply lockout the operation of the breaker or open then lockout. To perform this test, turn the test valve to the test position. Slowly open the purge valve until the gauge reads below 64 psi and the SF6 density monitor has switched for lockout. Then press the open and close buttons. If the breaker has a simple lockout the mechanism should not operate. If the breaker has an open then lockout function, the breaker should open on low pressure then pressing the buttons should not operate the mechanism.

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Figure 3.2. External Stroke and Wipe Measurement

3.5.3 ELECTRICAL TESTS 3.5.3.1 Contact resistance, (Ductor test)

It measures the integrity of the contact joints in the current path. This measurement can be made on the breaker before or after gas is in the tanks. The individual poles should be checked using a 100 A Ductor with 100 A flowing. A complete pole unit measured from bushing terminal to bushing terminal should measure 120 micro ohms or less with the breaker fully closed. Ductor readings taken after gas is in place should have no noticeable change.

Note: If readings are high, check the connection at the top of the bushing to ensure that the connection is not adding any additional resistance.

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3.5.3.2 Insulation resistance, (1000 V Megger Test)

It measures the integrity of the GCB insulation. For this measurement the breaker should have SF6 gas in the tanks to a pressure at or above the lockout pressure. The purpose for requiring gas is to insure a moisture free environment inside of tanks. Note that most of the leakage current will occur on the outside of the bushing insulator and not inside the gas tank.

1. Test with the breaker in closed position. Put the positive lead on one of the bushing terminals and the negative on the grounded gas tank. Value must exceed 1000 MΩ.

2. Test with the breaker in open position. Value must exceed 2000MΩ. There are two situations to test:

a. One is from terminal to terminal on each pole.

b. The other is from terminal to ground on each bushing.

3. If measured value is less than noted value, check as follows before concluding there is an internal problem:

a) Resistance measurements in the ΜΩ range with 1000 V Megger, can be sensitive to lead position similar to capacitance measuring. Shielded leads should be used for best results.

b) Outside of porcelain should be cleaned and a three-turn guard placed between second and third petticoat of each bushing and connected to the guard terminal of Megger.

c) Earth lead is connected to good ground on tank. Lead position is not important.

d) The connecting lead from the top of the bushing should be tied to keep lead from touching outside of bushing or any metal of breaker. Similar to 10 kV capacitance measuring.

e) Remove lead from bushing not connected to Megger, or keep tied to keep free of all parts of this segment and must not touch ground.

f) Connection to line post of Megger to be as short as possible to connect the test lead.

g) Tie clear of all metal parts or ground.

h) Do not touch earth, lead or Megger case.

i) Do not allow to sag and touch ground.

j) Personnel not to hold or touch leads.

k) Leads twisted together, laid on the ground or touching other possible leakage paths can make an insulator of 8000 ΜΩ or higher appear to be 500-1000 ΜΩ

l) Let the breaker gas environment reach equilibrium for one week. This will allow the desiccant to remove all of the moisture and allow the environment to reach steady state conditions.

m) Insulators may have a surface layer of moisture that should disappear within one week when gas with a dryness less than 150 ppm has been added and new desiccant is in place.

NOTE: Power factor tests are not required on SF6 bushings, these tests provide no useful information on SF6 filled equipment and are not recommended by HVB AE Power Systems, Inc. for our equipment.

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3.6 INSTALLATION & ASSEMBLY CHECK-LIST

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3-10


3-11


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3-13

CHAPTER 4. SF6 GAS SYSTEM

4.1 GENERAL INFORMATION

For safety considerations, consult Chapter 1 of this instruction manual before proceeding with these instructions. The SF6 gas system includes monitoring gas pressure, filling the GCB with gas and the gas sealing O-ring seals.

This chapter covers two gas monitoring systems, which use one of the following systems:

• A - the Qualitrol Temperature Compensated Gas Pressure Gauge as well as the optional non-temperature compensated monitoring.

• B - the Solon Temperature Compensated Gas Pressure Switch as well as the optional non-temperature compensated monitoring

The craftsperson should always refer to the breaker specific drawings to confirm which gas monitoring system is installed. Additionally, in a separate section, specific instructions for non-temperature compensated SF6 monitoring equipment is described. The customer can choose optional equipment to be used in your monitoring system that is covered in later sections of this chapter as well.

NOTE: Refer to your circuit breaker drawings to determine which sections of these instructions are relevant and refer only to those that apply.

NOTE: No maintenance is possible on any pressure/density switches supplied by HVB. No replacement parts are listed except for replacement of the complete device.

DISCLAMER: This chapter covers the most common gas systems, however due to the customized nature of the product, there may be differences with regards to customer preference. In which case, if questions arise due to such differences, it may be advisable to consult HVB AE Power Systems, Inc. to attain proper gas filling / system information.

4.2.A SF6 TEMPERATURE COMPENSATED PRESSURE GAUGE

This GCB uses a Qualitrol SF6 temperature compensated pressure gauge, (Figure 4.1A). The temperature compensated pressure gauge automatically adjusts its operating points higher or lower as a result of ambient temperature changes. There should be a label on gauge to indicate the part # and contacts settings.

As density changes the dial pointer moves. The switches themselves operate depending on the physical pointer position and are fixed and stationary. The switch contacts are factory adjusted for each switch value. As the pointer moves down the scale it contacts each switch in succession.

CHAPTER 4 GAS SYSTEMS

NOTE: This device and its internal switches ARE NOT field adjustable. If switches appear to be out of specs., contact HVB.

Figure 4.1A Temperature Compensated Pressure Gauge

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4.3A FILLING WITH SF6 GAS

NOTE: Read ALL of the instructions below prior to filling the breaker with SF6 gas.

1. The moisture content of the SF6 gas should be 150ppm, by volume, or less. The cylinder should be checked with a suitable hygrometer before using in the GCB. If the SF6 gas was supplied with the circuit breaker it is guaranteed to by dry to less than 150 PPM. Leave the hygrometer on until a reading of 150 PPM or lower has been obtained. If a reading of 150 PPM or lower cannot be reached, dry the hygrometer with dry air or nitrogen until below 100 PPM. Immediately recheck.

2. If moisture analysis is to be done on the GCB, use the fill valve for moisture sampling. If a reading of 150 PPM or lower is still not obtained wait one week and recheck during the cool morning hours. Finally, if a reading of 150 PPM is still not obtained, remove the gas and replace the desiccant in the tank with fresh bags and dry the gas if its to be re-used. Expected normal value should be under 100 PPM within one week.

NOTE: The filter drier should be replaced after having been used with 50 cylinders of gas. It is suggested a mark be placed on the filter drier to record each cylinder used. The dryer hose assembly should be capped at both ends when not in use. An SF6 gas cylinder will weigh about 225 pounds filled, with the gas content being constant at 115 pounds.

CAUTION: Do not remove the end covers of any SF6 piping until just before connection, this is to keep moisture out of the vessel and piping. Use dry air or nitrogen to purge the gas lines of moisture or material prior to connection. Keep dust, dirt, moisture, etc. from entering the lines prior to connection.

3. Put the 3-way test valve (Figure 4.2A) in NORMAL position. Then turn the discharge end of the valve on the gas cylinder to face the fill valve. Remove the shipping plug from the valve of the cylinder and the cap on the end of the adapter. Using the adapter with the left-hand threads, attach the filter-dryer to the valve in the cylinder. The fitting on the hose also has a sealing plug. Install the adapter on the fill valve. Tighten all connections, and then loosen the nut on the hose at the fill valve end with the valve closed. Slowly open the valve on the SF6 cylinder for approximately 30 seconds to purge the gas transfer assembly. Tighten the nut then close the valve on the cylinder. The connection is now filled with SF6 gas and ready to fill the breaker tank.

4. No regulator is required with the filter-dryer. An orifice with 0.05-inch diameter is installed between the filter and the gas bottle of the transfer hose to control the flow rate of the gas cylinder. Open the valve at the breaker, then the cylinder valve. The filling process can be detected by sound or condensation on the fittings.

5. Approximately 47 lbs of gas will fill the GCB from shipping pressure (approx. 5psig) to rated pressure (75 psig). The gas flow may stop due to chilling.

6. To measure the gas pressure, make sure the valve is in the normal position and allow the gas pressure to rise while being monitored.

7. During the filling of the breaker, a calibrated gauge need not be used to monitor the phase pressure. Determine the tank’s body temperature by attaching a thermometer to the shaded side of the tank. Do not read in less than fifteen minutes after attaching.

8. See breaker nameplate for standard gas system pressure. Fill the GCB till the reading on the gauge meets the reading on the tank within ± 3psig.

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9. Shut off the fill valve on the GCB gas tank and then the SF6 tank cylinder valve. Slowly loosen the connection at the cylinder to drain the pressure from the filter-dryer and fill hose.

10. Replace the cap in end of gas transfer tool to keep dirt and air out of the filter - dryer. Replace the safety cap on the SF6 cylinder and remove the cylinder.

11. Allow the gas pressure to balance for twelve hours and then re-check the pressure. If additional gas is needed, repeat the steps above.

Figure 4.2A. Valves In The Gas System

4.4A SF6 LEAK RATE AND LEAK DETECTION

The maximum permissible design leakage is one psi per year. The rise and fall of pressure should be observed for a period of one month to determine the loss due to leakage. Remember that the pressure switch on the breaker is temperature compensated. When checking with a regular gage, changes in pressure due to temperature fluctuations must be taken into consideration. An allowance equal to about 1 1/2 psig for every five degrees C should be made for variation in temperature.

If leakage is determined in excess of one psig per year, use an SF6 gas leak detector at all gaskets, bolted and flared joints. If an SF6 instrument is not available, a high viscosity solution, such as “Leak Tec Formula 277CHV”, can be used. The solution should be cleaned from the surface using a clean damp cloth completes the leak checking.

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4.5A SF6 TEMPERATURE COMPENSATED GAS MONITORING SYSTEM

The temperature compensated gas monitoring system is provided with a three phase common pressure-monitoring scheme that gangs the pressure of all three phases together to a single temperature compensated pressure gauge ( Figure 4.3A). An optional individual phase monitoring systems is available and described in later section of this chapter.

Figure 4.3A. Three Phase Common Gas Monitoring System

The typical system is furnished to provide an alarm circuit when the pressure in the interrupter tank falls bellow 67 psig at 20° C. Additional contacts can enable the system to provide a command at 64 psig at 20°.

The minimum operating pressure for full dielectric strength and interrupting capacity is 64 psig at 20° C. Below this pressure the breaker should be isolated from the system. Operation of the circuit breaker below this pressure can result in damage due to reduced backpressure in the puffer cylinder and excessively high operating speeds and a failure to interrupt due to low dielectric strength caused by insufficient SF6 gas.

SF6 in the gaseous state will show a change in pressure as its temperature is changed. This is represented by the curve shown in Figure 4.5. The table (Figure 4.4) shows the SF6 Temperature versus Pressure Nameplate that is normally provided on the cabinet door.

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4.2.B TEMPERATURE COMPENSATED PRESSURE SWITCH

This GCB uses a Solon SF6 temperature compensated pressure switch and a regular pressure gauge (Figure 4.1B). The temperature compensated pressure switch automatically adjusts its operating points higher or lower as a result of ambient temperature changes. There should be a label on each switch to indicate the part # and switch settings.

Temperature compensation is accomplished internally by a Bi-metal disk springs. It is recommended that the pressure settings not be adjusted in the field. If the switch appears to be out of tolerance contact HVB AE Power Systems, inc. for instructions.

NOTE: Do NOT adjust Pressure Switch. If Switch appear to be out of specs., contact HVB.

OPERATION PSI 63GDA Operates on Descending Pressure 67±2

Resets on Ascending Pressure 69±2

63GDC Operates on Descending Pressure 64±2

Resets on Ascending Pressure 68±2

Figure 4.1B Temperature Compensated Pressure Switch

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4.3B FILLING WITH SF6 GAS

NOTE: Read ALL of the instructions below prior to filling the breaker with SF6 gas.

1. The moisture content of the SF6 gas should be 150ppm, by volume, or less. The cylinder should be checked with a suitable hygrometer before using in the GCB. If the SF6 gas was supplied with the circuit breaker it is guaranteed to by dry to less than 150 PPM. Leave the hygrometer on until a reading of 150 PPM or lower has been obtained. If a reading of 150 PPM or lower cannot be reached, dry the hygrometer with dry air or nitrogen until below 100 PPM. Immediately recheck.

2. If moisture analysis is to be done on the GCB, use the fill valve for moisture sampling. If a reading of 150 PPM or lower is still not obtained wait one week and recheck during the cool morning hours. Finally, if a reading of 150 PPM is still not obtained, remove the gas and replace the desiccant in the tank with fresh bags and dry the gas if its to be re-used. Expected normal value should be under 100 PPM within one week.

NOTE: The filter drier should be replaced after having been used with 50 cylinders of gas. It is suggested a mark be placed on the filter drier to record each cylinder used. The dryer hose assembly should be capped at both ends when not in use. An SF6 gas cylinder will weigh about 225 pounds filled, with the gas content being constant at 115 pounds.

CAUTION: Do not remove the end covers of any SF6 piping until just before connection, this is to keep moisture out of the vessel and piping. Use dry air or nitrogen to purge the gas lines of moisture or material prior to connection. Keep dust, dirt, moisture, etc. from entering the lines prior to connection.

3. Put the 3-way test valve (Figure 4.2B) in NORMAL position. Then turn the discharge end of the valve on the gas cylinder to face the fill valve. Remove the shipping plug from the valve of the cylinder and the cap on the end of the adapter. Using the adapter with the left-hand threads, attach the filter-dryer to the valve in the cylinder. The fitting on the hose also has a sealing plug. Install the adapter on the fill valve. Tighten all connections, and then loosen the nut on the hose at the fill valve end with the valve closed. Slowly open the valve on the SF6 cylinder for approximately 30 seconds to purge the gas transfer assembly. Tighten the nut then close the valve on the cylinder. The connection is now filled with SF6 gas and ready to fill the breaker tank.

4. No regulator is required with the filter-dryer. An orifice with 0.05-inch diameter is installed between the filter and the gas bottle of the transfer hose to control the flow rate of the gas cylinder. Open the valve at the breaker, then the cylinder valve. The filling process can be detected by sound or condensation on the fittings.

5. Approximately 47 lbs of gas will fill the GCB from shipping pressure (approx. 5psig) to rated pressure (75 psig). The gas flow may stop due to chilling.

6. To measure the gas pressure, make sure the valve is in the normal position and allow the gas pressure to rise while being monitored.

7. During the filling of the breaker, a calibrated gauge need not be used to monitor the phase pressure. Determine the tank’s body temperature by attaching a thermometer to the shaded side of the tank. Do not read in less than fifteen minutes after attaching.

8. See breaker nameplate for standard gas system pressure. Fill the GCB till the reading on the gauge meets the reading on the tank within ± 3psig.

9. Shut off the fill valve on the GCB gas tank and then the SF6 tank cylinder valve. Slowly loosen the connection at the cylinder to drain the pressure from the filter-dryer and fill hose.

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10. Replace the cap in end of gas transfer tool to keep dirt and air out of the filter - dryer. Replace the safety cap on the SF6 cylinder and remove the cylinder.

11. Allow the gas pressure to balance for twelve hours and then re-check the pressure. If additional gas is needed, repeat the steps above.

Figure 4.2B Valves In The Gas System

4.4B SF6 LEAK RATE AND LEAK DETECTION

The maximum permissible design leakage is one psi per year. The rise and fall of pressure should be observed for a period of one month to determine the loss due to leakage. Remember that the pressure switch on the breaker is temperature compensated. When checking with a regular gage, changes in pressure due to temperature fluctuations must be taken into consideration. An allowance equal to about 1 1/2 psig for every five degrees C should be made for variation in temperature.

If leakage is determined in excess of one psig per year, use an SF6 gas leak detector at all gaskets, bolted and flared joints. If an SF6 instrument is not available, a high viscosity solution, such as “Leak Tec Formula 277CHV”, can be used. The solution should be cleaned from the surface using a clean damp cloth completes the leak checking.

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4.5B SF6 TEMPERATURE COMPENSATED GAS MONITORING SYSTEM

The temperature compensated gas monitoring system is provided with a three phase common pressure-monitoring scheme that gangs the pressure of all three phases together to a single temperature compensated pressure switch and a regular pressure gauge ( Figure 4.3B). An optional individual phase monitoring systems is available and described in later section of this chapter. The typical system is furnished to provide an alarm circuit when the pressure in the interrupter tank falls bellow 67 psig at 20° C. Additional contacts can enable the system to provide a command at 64 psig at 20°.

The minimum operating pressure for full dielectric strength and interrupting capacity is 64 psig at 20° C. Below this pressure the breaker should be isolated from the system. Operation of the circuit breaker below this pressure can result in damage due to reduced backpressure in the puffer cylinder and excessively high operating speeds and a failure to interrupt due to low dielectric strength caused by insufficient SF6 gas.

SF6 in the gaseous state will show a change in pressure as its temperature is changed. This is represented by the curve shown in Figure 4.5. The table (Figure 4.4) shows the SF6 Temperature versus Pressure Nameplate that is normally provided on the cabinet door.

Figure 4.3B Three Phase Common Gas Monitoring System

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4.6 TESTING SF6 SYSTEM PRESSURE

A valving arrangement to check the SF6 gas pressure alarm switch has been built into the gas system and may be used in the following manner:

1. Remove all AC and DC connections to the control cabinet. Failure to do the will cause the breaker to send low gas alarms and the breaker will lockout when testing the lower pressure value

2. Turn test valve off, perpendicular to the direction of gas flow. This isolates the SF6 temperature compensated pressure switch from the breaker tank. Very slowly continue to turn the test valve while watching the pressure gauge. Allow the pressure to drop gradually. The pressure at which the temperature compensated pressure switch operates will represent the alarm or command pressure.

3. Return the handle to the initial position, parallel to the gas flow. Failure to do so will leave the switch isolated from the pressure vessels resulting in a hazardous system with no protection against low SF6 gas pressure.

4. To ensure accurate testing:

a. Check all pressures after the breaker has been de-energized minimum 6 hours

b. Take the readings early in the morning. This is when the gas and metal of the cabinet will be at the closest temperature.

c. The temperature of the SF6 tank should be checked and used as the gas temperature.

d. See the SF6 Pressure vs. Temperature Table (Figure 4.4.), for pressure at the recorded temperature.

SF6 Gas Temperature vs. Pressure

Temperature Pressure

In Degree C In Degree F PSIG

-30 -22 57

-20 -4 60

-10 14 64

0 32 68

10 50 71

20 68 75

30 86 79

40 104 82

50 122 86

60 140 90

Figure 4.4. SF6 Gas, Pressure vs. Temperature Table

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Figure 4.5. SF6 Pressure Versus Temperature Curve

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4.7 OPTIONAL PRESSURE SYSTEM - INDIVIDUAL PHASE MONITORING

An optional SF6 system is used on many of the circuit breakers provided by HVB AE Power Systems, Inc. Essentially this system is the same as the system covered beginning on page 2 of Chapter 4, with the addition of lines for each phase’s tank connected to a separate pressure monitor.

This system is available on any model offered by HVB and provides single phase monitoring rather than the manifold system that monitors the total circuit breaker as a single source of SF6 gas. The three-phase system provides for command and alarm switches for each pole.

All information regarding adjustment, settings and system pressures should be the same as previously described for single phase monitoring. The only difference is the number of pressure gauges or switches and regular pressure gauges (3) now would reflect the number of poles.

The customers “Device Sheet” and “Electrical Diagrams” should be referenced to determine the system provided.

4.8 PULLING VACUUM

In the event that the SF6 gas was removed and the GCB was vented to the atmosphere it is necessary to replace the gas. Before filling the breaker with SF6 gas it is necessary to replace the desiccant and pull a vacuum on the GCB. The procedure is as follows:

1. Replace desiccant in the circuit breaker with fresh desiccant. Pull vacuum until a reading of 1000 microns is reached. This pressure should be held for 2 hours once reaching 1000 microns.

NOTE: For instrument references 1000 microns is equal to one millimeter of mercury and the same as one Torr.

2. Close the gas-filling valve before attaching the vacuum unit and do not open until the vacuum is running. Always close the gas-filling valve before stopping the vacuum pump. Failure to close the gas-filling valve first may result in oil being drawn from the pump into the tank.

3. Normal evacuation equipment will reach 1000 microns within approximately one-half hour.

4. Do not evacuate unless SF6 gas is available and will be added the same day. Enough gas should be added to a minimum of five psig, but normal operating pressure is recommended.

4.9 O - RINGS AND GASKETS INSTALLATION

O-rings and gaskets are used in the design of the gas circuit breaker and it is important that the O-rings and gaskets are handled properly to avoid leakage problems. Emphasis must be placed on the importance of using only factory approved O-rings and gaskets in any location. Considerable research has been conducted to arrive at the current O-rings an gaskets for the proper application. A second precautionary step is to avoid using excess lubrication during installation of the O-rings and gaskets. Use only a minimum of the proper lubricant.

The proper installation is described in the following:

1. Inspect the parts on which the O-rings or gaskets is to be assembled to be sure no burrs, sharp edges or foreign materials are present.

2. The two surfaces, between which the O-ring or gasket will be compressed, should be free of any visible scratches or sharp changes in surface. If it is deemed necessary to repair an O-ring or gasket surface the imperfection should be blended into the main surface over a width of approximately one-

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quarter inch minimum in order to provide a tight gas seal. This is typically done with a fine emery cloth. Be sure to clean thoroughly to remove any metal or sandpaper articles.

3. To assemble, place the O-ring or gasket with a minimum force into the groove (DO NOT OVER STRETCH THE O-RING OR GASKET TO PLACE IT IN THE GROOVE). If stretching was performed to seat the O-ring or gasket, allow time for it to return to its normal diameter before closing the opening. O-rings or gaskets should not be twisted. Twisting during installation will occur with a lack of lubrication and the incorrect ratio of inside diameter to cross-sectional diameter.

4. Assembly of the parts must be accomplished by straight longitudinal motion. Rotary or oscillatory motion may cause pinching or cutting of the O-ring or gasket seal.

5. Operate the moving parts by hand to be sure there is no binding.

6. If an O-ring or gasket is being removed from a part for examination, never reuse it. A new O-ring or gasket must be installed upon removal of the original. Prior to examination check with HVB AE Power System, inc. for spare O-ring or gasket.

7. Extreme care must be exercised when removing an O-ring or gasket for replacement or examination. Do not use a metallic instrument (i.e., screwdriver, pin, scale, etc.). The proper method to remove an external O-ring is to grip the piston or part firmly with one hand and with the thumb and the first finger of the other hand, exert a compressive horizontal force to the sides of the O-ring, causing it to bulge out sufficiently so that it can be removed from the groove. To remove an internal O-ring, a non-metallic instrument must be used to prevent scarring of the groove and causing leakage.

8. Recommended procedure for lubricating any O-ring or gasket, is to clean it thoroughly with a clean cloth (no solvents) and cover the O-ring or gasket completely with a thin film of the prescribed lubricant before assembling it into the groove. Again, avoid over and under lubricating. Do not apply lubricant directly from the applicator to the gland, groove, or the installed O-ring or gasket. Excessive grease can cause contamination problems. Under-lubrication can result in abraded rings, rolling, and increased friction of the sliding surface. It is very important that the correct lubricant be used on the O-rings or gaskets. Use of a lubricant, which is not compatible with the O-ring or gasket material, can result in the deterioration of the O-ring or gasket and leakage at the seal.

9. O-ring or gasket material is Buna-N (black). Hitalube 280 should be used only, for lubrication.

4.10 SWAGELOK GAS SEAL SYSTEM

HVB AE Power Systems, Inc. exclusively uses Swagelok connectors and parts in our gas system. Figure 4.6. shows an example of Compression Fitting.

Figure 4.6. Swagelok Compression Fitting

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4.11 RUPTURE DISK

The rupture disks are located on the end covers (Figure 4.7) of the tanks, opposite the mechanism. The rupture disk is a reverse buckling style. This is the state of the art in rupture disk technology available today. The rupture disk is rated to burst at the MAWP (Maximum Allowable Working Pressure) of the gas tank. The rupture disk is made of Inconel, this is a grade of steel with the corrosion resistance of stainless.

Safety glasses must be worn when working near the rupture disk. If the disk were to burst, the entire gas pressure of the GCB will burst from the tank in a matter of moments. The force of the blast and the temperature of the gas would be dangerous and could cause serious injury. To avoid this, a flow diverter is installed in front of rupture disk and it will direct the gas flow to a safe direction.

Occasionally it may be necessary to inspect the rupture disk. To inspect remove the flow diverter and examine the disk. The disk should bulge into the tank and be very smooth and symmetrical. Any irregularities or cracks imply that the disk must be replaced, inspect the ends of the pressed in lines carefully for irregularities. Again what you are looking for, are irregularities from a symmetrical shape.

The rupture disk is not a serviceable item. In the unlikely event that the rupture disk opens please order a new one from HVB spare parts and replace it.

Figure 4.7. Rupture Disk Assembled to End Cover

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4.11.1 Rupture disk replacement

To replace the rupture disk:

1. Completely remove the SF6 gas.

2. Remove the flow diverter.

3. Remove the rupture disk, (a 13 mm socket wrench is required).

4. Clean and inspect the O-ring groove.

5. Install a new O-ring, (lubricate it according to the procedure).

6. Carefully install the rupture disk (be sure that it is centered over the opening in the gas tank).

7. Install the flow diverter (be sure the openings of flow diverter are oriented horizontally).Torque all the M8 bolts to 10 ft-lbs.

8. Remove the end cover bolts (24 mm socket wrench).

9. Take the end cover and place it on a clean surface.

10. Remove the desiccant plate bolts (5mm hexagon wrench).

11. Replace the desiccant bags by new ones then install the desiccant plate. Torque the M8 bolts to 10 ft-lbs.

12. Clean and inspect the O-ring groove and the sealing surface of the gas tank.

13. Install a new O-ring, lubricate it according to the procedure.

14. Install the end cover to gas tank. Torque the M16 bolts to 45 ft-lbs.

4.12 CRANKBOX ROTATING O-RING SEALS

The crankbox shafts are sealed by rotating O-rings, located as shown in Figure 4.8. Also this figure describes the part# and the quantity of O-rings/Breaker.

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Figure 4.8. Crankbox O-rings

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CHAPTER 5 MAINTENANCE 5-1

5-1

CHAPTER 5. MAINTENANCE

5.1 SAFETY NOTE

Each user is responsible for instructing all personnel associated with his equipment on all safety precautions that must be observed. See the section on safety located in the installation manual.

5.2 REPLACEMENT PARTS

This manual does not include a replacement parts section. For replacement parts please see the spare parts catalog. When parts are required the serial number of the breaker, the part number, and the description should be given on the purchase order.

5.3 GENERAL NOTES

Dependable service and safety of power equipment is contingent upon the unfailing performance of the power circuit breaker. To maintain such service, it is recommended that a well-defined inspection and maintenance schedule be set up and followed, as serious shutdowns can often be avoided by locating potential sources of trouble in an early stage. A periodic lubrication of parts subject to wear is also vitally important for the successful operation of the breaker and operating mechanism.

The frequency of periodic inspection should be determined by each operating company on the basis of the number of operations (including switching), magnitude of currents interrupted, and any unusual operations that occasionally occur. Operating experience will soon establish a maintenance schedule that will give assurance of proper breaker condition. Schedule periods may be shortened or lengthened after the customer determines the condition of the breaker during the first few maintenance checks.

The following recommendations to be observed during either a routine or periodic inspection.

1. Review the SAFETY SECTION at the front of the book. Note items that will be involved during intended inspection.

2. Be sure the breaker and its mechanism are disconnected from all electrical power, both high voltage and operating controls, before inspecting or repairing.

3. Apply ground leads to all entrance bushings.

4. Use the connection diagram accompanying the breaker in all cases when testing and connecting the controls.

5. Before any work is attempted on the operating mechanism, ALL of the springs (Opening and Closing) must be discharged.

6. After making any adjustments on the breaker, operate the apparatus by hand before attempting electrical operations.

7. When the breaker interrupter is to be inspected, the SF6 gas should be removed with proper gas handling equipment.

5.4 INSPECTION AND MAINTENANCE SCHEDULE

It is assumed that the safety instructions have been reviewed and fully understood before any detail maintenance is attempted. The detail instructions will include only safety notes that may apply to the part being discussed.

The HVB AE Power Systems, Inc. gas circuit breaker has been designed for simplicity and minimum maintenance requirements. It is expected, due to the low number of yearly operations of high voltage breakers, that the time factor and not number of operations or interruption duty will normally determine the maintenance schedules.

The inspection and maintenance can be separated into three types: Patrolling, Routine and Periodic (Table 5.1). See the installation chapter for the tool list required for inspections and maintenance.

Assemblies Installation Patrolling Routine Periodic

Monthly 3Y or 500 Operations

12Y or 2000Operations

SF6

Compensate Pressure Gauge

X X X

Compensate Pressure Switch + Regular Pressure Gauge

X X X

Gas Piping X X X

Moisture Level X X X

Mechanical

Timing Tests X X X

External Stroke X X X

Operational tests X X X

Electrical

Contact Resistance X X X

Insulation X X X

Bushings

Dirt X X X

Damage X X X

Cabinet

5-2CHAPTER 5 MAINTENANCE 5-1


Wiring Secure X X X

Aux. Sw. Links secure X X X

Fuse Blocks, Switches Secure

X X X

Relay Contacts X X X

Heaters Energized X X X

Heaters Thermostat X X X

Motor Gear Train and Mech. Links

X X X

Unusual Noise

SF6 Gas X X X

Electrical Noise X X X

Record

Mechanism Counter X X X

Gas Pressure X X X

Ambient Temp X X X

Dashpot

Oil Leak X X X

Oil Level X X

Oil Replacement X

Aux. Switch

Links X X

Wiring Secure X X

Counter X X

Mechanism

Close, Trip, Latches X X

Charging System X X

Coils Resistance X X

Mech./Crankshaft Connection

X X

Touch up Paint

And Caulk

X X

Interrupter

Arcing Contacts X

Teflon Nozzles and Teflon Covers

X

Crankbox O-ring Seals

Replacement X

Table 5.1. Inspections and Maintenance Schedule 5.4.1 Patrolling Inspection and Maintenance 5.4.1.1 GENERAL

Interval: weekly-to-monthly as best suits the customer's conditions.

This is an observation and data recording inspection that can be expected to limit emergency maintenance requirements by noting possible problems and arranging a planned time for corrections. These recordings must be analyzed to derive full benefit from them and keep the breaker utilization at a high level.

The Patrolling Inspection is done under following conditions:

1. Breaker NOT removed from service.

2. SF6 gas NOT removed

3. Breaker in ANY position open or closed.

4. If any of the inspections indicate the GCB is not to specifications refer to either the Routine Maintenance Section or the specific section that covers the out of specification item.

5.4.1.2 PATROLLING INSPECTION AND MAINTENANCE DETAILS

1. Interval one week to one month, as best suits the customer’s conditions, but should be regular.

2. Visual inspection for unusual conditions.

a. Entrance Bushings

i. Excessive dirt

ii. External damage

b. Cabinet

i. All wiring appears secured

ii. Drive links to auxiliary switch

iii. All fuse blocks or switches appear tight or normal.

iv. Relay contacts show no excessive arcing

v. The 160-watt heaters (located on the upper left side of cabinet) should be energized at all time, depending on customer requirement

vi. Check the settings of the thermostat heaters

vii. Inspect motor gear train and mechanism links. To do this a mirror will be helpful.


c. External

i. Inspect Dashpot for oil leaks.

d. Unusual Noise

i. SF6 gas system, leaks

ii. Electrical noise in entrance bushing area or internal to the gas tanks.

e. Record

i. Mechanism counter

ii. Gas pressure. If the pressure is 5 psig below normal, check for leaks at a planned outage or next routine maintenance. For patrolling inspection it is suggested the plus or minus error, at normal pressure, be marked on the face with a marking pencil.

iii. Ambient temperature

f. Dashpot

i. Inspect for Oil Leak

5.4.2 Routine Inspection and Maintenance

5.4.2.1 GENERAL

Interval: 500 operations or 3 years interval whichever comes first.

During this inspection are checked: the electrical current path, the SF6 gas system, the control relays and the mechanism.

The Routine Inspection is done under following conditions:

1) Breaker removed from service

2) SF6 gas NOT removed

3) Breaker in open position and ALL springs discharged

4) If any of the inspections indicate the GCB is not to specifications refer to either the Periodic Maintenance Section or the specific section that covers the out of specification item

5.4.2.2 ROUTINE INSPECTION AND MAINTENANCE DETAILS

1) All patrolling items

2) Contact resistance measurement

3) Insulation resistance check

4) Check gas pressure devices

5) Check all gas piping for tightness or leaks

6) SF6 gas moisture check. Performed on a new breaker or periodic inspection refill

a) Moisture should be under 150 ppm, by volume


b) Check after 24 hours. If moisture is under 300 ppm but greater than 150 ppm, proceed to next step

c) Check at one week. If under 150 ppm proceed. If above 150 ppm remove gas for drying and replace desiccant

d) Check moisture at one month - if satisfactory omit checks until routine inspection

7) Check Dashpot for oil leak and oil level a) Check oil level by taking out the bolt located at the up end of Dashpot. The oil level should be at lower

side of the bolt hole.

8) Check Auxiliary Switch

a) Check the linkage from the output crank to the auxiliary switch linkage. Be sure all screws, nuts, cotter pins and retaining rings are in place and tight. If any need to be tightened use red Loctite 271 to secure the fasteners.

b) Check all wires to auxiliary switch for tightness.

c) Check that the counter functions properly.

9) Check and lubricate (apply a small amount of Gleitmo 805 K) the Mechanism

NOTE: There is no adjustment in the Mechanism. During breaker duty time, if any mechanism malfunction observed, contact immediately HVB AE Power Systems, inc.

a) Lubricate close and trip latches (Figure 5.2) and check cotter pins and retaining rings

i) Check the free motion of the latch shafts ensure that the spring return is working

ii) Check the free rotation of the latch rollers also look for damage to the rollers

b) Check charging system. Operate breaker several times by opening and closing the interrupter using the push buttons. Observe the operation of the motor and gear train system. Check the following conditions:

i) Motor is securely mounted

ii) Gear train is running smoothly iii) Inspect the gap between the pawls and the gear. There should always be a minimum gap of 1

mm after the motor stops iv) Time the charging operation; a second hand on a wristwatch is adequate. Ensure that the

charging cycle completes in 15 seconds or less. If the motor stops before complete charging cycle, open and close the motor circuit by control power breakers/fuse blocks/knife switches, to reset the motor overrun relay.

v) Lubricate the gears

c) Measure the resistance of the Trip and Close Coils, (125 VDC; 12.3±5% ohms, at 68 F)

d) Check the lock nuts for the mechanism rod connected to crankshaft. If any of these nuts are loose the linkage must be readjusted and the timing must be rechecked. The Red Loctite 271 should be used to secure the fasteners.


10) Mechanical Tests

a) Timing Test (Operating curves) - Appendix 2. Can be observed the over travel value at closing operation.

b) External stroke. When power-operating curves cannot be obtained then a mechanical stroke test should be made using the manual screw at the end of open spring housing.

c) Operational test. When all other work is completed a close, open and trip-free check curves should be taken at normal pressure and voltage.

11) Touch up paint and caulk as found necessary.

Routine inspection may also indicate the necessity of an internal inspection if:

• The contact resistance is high or inconsistent between phases.

• Insulator resistance low.

• Contact parting times out of tolerance as indicated by operating curves. Assuming routine inspections are stable and interruption duty is light, the interruption inspection as determined by these facts may well exceed 20 years. It is therefore recommended that at least one breaker in a yard be inspected at the first 12 year periodic maintenance to verify the interrupter is stable. The customer can then adjust the interrupter inspection period as indicated by this inspection.


Figure 5.2. Mechanism’s Latches

5.4.3 Periodic Inspection and Maintenance

5.4.3.1 GENERAL

Interval: 2000 operations or 12 years whichever comes first.

During this inspection and maintenance the operating mechanism will be lubricated. The interrupter may need to be inspected depending on number of operations. The interrupter inspection is normally determined by the interruption duty (Table 5.3.)

Current Interrupted Number of Operations Between Inspections


20,000 to 40,000 Amps 10

15,000 to 20,000 Amps 30

5,000 to 15,000 Amp 100

Rated Load Current 2,500 Amp 2000

Table 5.3. Number of Operations between Inspections

The Periodic Inspection is done under following conditions:

1) Breaker removed from service.

2) SF6 gas removed.

3) Breaker in open position and ALL springs discharged.

4) If any of the inspections indicate the GCB is not to specifications refer to either the Periodic

(1) Maintenance Section, or the specific section that covers the out of specification item.

5.4.3.2 PERIODIC INSPECTION AND MAINTENANCE DETAILS

1) All Patrolling Inspections

2) All Routine Inspections

3) Interrupter Inspection, (Figure 2.2)

The Periodic Inspection should proceed as follows:

a) Perform timing tests before the Interrupter Inspection

b) Discharge both closing and opening springs

c) Remove power from the motor circuit by opening control power breakers, fuse blocks or knife switches

d) Close and open the breaker using the push buttons until all springs are discharged

e) Then remove control power from entire control circuit

f) Remove and store SF6 gas

g) Remove end covers (desiccant covers)

h) Inspect the inside of the tank for white powder and other arc debris. Small fine powder material is to be expected. Long slivers or whiskers are not acceptable. Contact HVB if there is any question about the material found.

i) Remove and inspect the arcing contacts:

• Inspect the surface at end for excessive burning. Remove all high spots with a fine file. Measure total length and replace if it does not meet the following specs:

NEW - 187 mm MINIMUM -184 mm


• Also replace if difference between peaks and valleys exceeds three mm

• When arcing tip shows almost no damage, inspect moving contacts with a mirror, through the nozzle. If internal parts look good do not disassemble

• Contact tip may show slight galling. Polish lightly with #400 paper to remove high spots. This is a current carrying surface and will need to be replaced when excessive galling is present.

j) Remove and inspect teflon nozzles and teflon covers:

• Inspect the tapered entrance of the teflon nozzle for damage, in the fully closed position. Black oval marks around the small inside diameter will indicate contact hitting during operations.

• The slope leading into the diameter may show black marks or slight depressions due to contact hitting the surface during re-closing operations. Clean and lightly polish with fine paper to remove black mark, but depressions do not have to be removed. The internal diameter will also have black rub marks from the contact. Clean only, do not polish or the life of the nozzle will be reduced.

• Nozzle inside diameter at smallest diameter should be checked. Replace if it does not meet the following specs:

NEW - 28 mm MAXIMUM - 29 mm

• Check end diameter in teflon cover. Replace if it does not meet the following specs:

NEW - 26 mm MAXIMUM - 27 mm

k) All parts should be cleaned with 99% isopropyl alcohol only and lint free wipes before re-assembly

l) Check all other interrupter parts for tightness then clean with 99% isopropyl alcohol and lint free wipes

m) Install the teflon nozzles, teflon covers, arc contacts

n) Contact resistance check per ROUTINE INSPECTION. This may be performed with or without SF6 gas

o) Add new desiccant to containers and reattach desiccant covers using new “O” rings. See spare parts book for part number

p) Recharge with SF6 gas per SF6 GAS SYSTEM

q) Check for gas leaks per the INSTALLATION SECTION

r) Final operating curves per ROUTINE INSPECTION.

4) Crankbox O-rings Replacement

The rotating O-ring seals should be replaced. Refer to Chapter 4, Figure 4.8, for the rotating O-ring

locations, part# and quantity. No special tools and jigs are required to replace these O-rings.

5) Dashpot oil Replacement

The oil dashpot and the O-ring seals should be replaced. The HVB approved oil is:

SHELL SPECIAL FLUID, qty = 2L or 2.1Qt.

The internals parts of the Dashpot are not user serviceable.


APPENDIX

APPENDIX 1. TORQUE VALUE CHART

THREAD SIZE STEEL INTO STEEL STEEL INTO ALUMINUM / COPPER/ BRASS

[lbf-ft] [N X cm] [lbf-ft] [N X cm]

M6 5 490 2 294

M8 10 1177 6 784

M10 15 1961 10 1177

M12 35 4413 25 2942

M16 70 9316 45 5884

M20 130 17652 80 10787

M24 300 41188 140 18633

M30 505 68647 275 37265

M36 870 117680 475 64724

M42 1450 196133 795 107873

APPENDIX 2. OPERATION TRAVEL CURVES

2.1. CLOSE

2.2. OPEN

2.3. TRIP FREE

2.4. RECLOSE

REVISION HISTORY

REVISION 8: ADDED PARAGRAPH 3.2.1. f, page 3-2

REVISION 9: ECO 110029, REMOVED THE OPERATION OF MOTOR CHARGING CIRCUIT AND WARNING PARAGRAPHS (PAGES I-III).

HVB AE Power Systems, Inc. 7250 McGinnis Ferry Road

Suwanee, GA 30024 Telephone: 770-495-1755 Fax: 770-623-9214

I.B.-R9

Documents

full dielectric

descending

gas transfer

operating

lint free

auxiliary

cool morning

insufficient