Generator Maintenance

Excellence in Product Support

Caterpillar Confidential: Yellow

2011 TC ConferenceLafayette, IN

Generator Maintenance

Speaker:Aaron Kempf


2011 TC ConferenceLafayette, INElectric

PowerPage 263 Caterpillar Confidential: Yellow

Overview Shipping Maintenance Startup Maintenance Regular, Periodic and Annual Maintenance Monitoring Recommendations Insulation Test Recommendations Bearing Temperature Guidelines Bearing Replacement Stator Temperature Guidelines Vibration Measuring Guidelines Important Updates Maintenance Literature

Agenda




Overview Scheduled Maintenance

Who: Customers and Dealers! CAT Warranty Statement states that the User is responsible for

performance of the required maintenance. What: Applications

All Applications (Standby, Prime, Continuous, etc.) Where:

Onsite, before/during/after Storage, before/after Shipping When: Product Life

Shipping, Storage, Start-up, Regularly, Periodically, Annually How: Procedures

Cleaning, Drying, Storage, Insulation Resistance, Alignment, Vibration, Bearing Greasing, Bearing Temperature Monitoring, Stator Temperature Monitoring, Controls and Protection Settings

Why: Publications (OMMs and SOTAs for SR4,SR4B, and SR5) SENR5359, SEBU6918, SEBU7270, SENR7968, KENR5284




What happens when shipping maintenance is not effective?

Generator Maintenance - Shipping




Packaging Proper generator set cover protection needs to be in place for the

environment generator set is being shipped in. Handling

Proper lifting of generator sets using lifting eyes and fixtures. Refer to respective OMM for more information.

Shipping damages cant be claimed as warranty. These damages should be claimed through the shipping/freight company.

Example of generator foot damage from shipping

Example of grease deterioration after improper shipping and storage

Generator Maintenance - Shipping




REFERENCE:SEHS9031 Storage

Procedure for Caterpillar

Products

Generator Maintenance - StorageBelow are some photos of adequate and inadequate storage practices.In these examples, the generators/sets should be properly covered from the elements when stored.

BAD

BADBETTER

BEST

Tight wrapping is good for shipping and short storage times. If longer storage is required, make sure to cover the package loosely.




Dry Location Cover for protection Loose to allow generator to breathe

Turn rotor ten (10) revolutions every sixty (60) days Maintain winding temperature

At least 5 C higher than the ambient temperature Space heater

Insulation test (reference SEHS9124) Insulation test must be done when generator is

received Insulation test must be repeated prior to start-up.

Generator Maintenance - StorageMake sure to complete when package is not installed and

there is no intention of installing in the near future.

Make every effort to complete when package is in storage

and make sure to complete when package is being installed or is installed and not running (i.e.,

standby).

Example taken from SEBD0660 showing condensation inside

the generator.Example of hot spot created on bearing race

after long storage period without rotor turning.




Generator Maintenance - Start-up Before applying battery and shore power voltage to the Generator Set

Inspect generator for debris, foreign objects, leaks and loose

connections, broken fittings, rubbing or damaged wiring, guards and

components. Repair as necessary.

i.e., Lead chaffing from generator stator to bus.

Check for proper grounding.

(Reference REHS4634)

Check space heaters for proper operation.

Example of loose PMG bolts, not noted before startup




Generator Maintenance - Start-up System check prior to Generator Set operation

Must DOCUMENT data on each for future reference Alignment (LEBW4975, SEHS7654, SEHS7259, SEHS7073, REHS0177). Air gap (main generator, exciter, & PMG) even around circumference Insulation test (Reference SEHS9124) Measure Generator winding resistances

(SENR5359 for SR4B, KENR5284 for SR5) Main Stator/Rotor, Exciter Stator/Rotor, PM Stator/Rotor Compensate readings for temperature and use micro-ohmmeter Record for trend plotting!

Coordination of settings Generator control and protective settings Factory default settings not applicable to every application Dealer and/or third party consultant is responsible for Coordination Study

at each site Circuit breaker ECM, EMCP, and CDVR, Droop (KW and KVAR) Differential Protection, Reverse KVAR Protection, etc.




Generator Maintenance - Start-up System check when Generator Set is running

Must DOCUMENT data on each for future reference Record the following at No Load and Full Load

Bearing temperature (per respective OMM) Stator temperature (per respective OMM) Air inlet temperature (and at areas where air recirculation could exist)

Confirm no air recirculation is occurring Refer to TMI generator information and generator nameplate

Vibration levels (Reference A&I Guide LEBW4972) Voltage regulator & excitation system

Sensing voltage Excitation voltage and current (refer to TMI generator information)

Determined by Load and Power Factor




Generator Maintenance - Start-up After stopping the Generator Set

Inspect the generator and report malfunctions.

Inspect for loose, broken, rubbing or damaged wiring or

components.

Make repairs or adjustments to the generator set as necessary.

Check that generator air inlet filter is clean, if applicable.

Verify generator space heater is operating.




Generator Maintenance - Regular

During Generator Set operation

Must DOCUMENT and TREND data on each for future

reference

Monitor Phase current, Neutral current, Voltage, Frequency,

Power Factor, Harmonic content, and Load variation

Monitor Room Temperatures

Monitor Bearing and Stator temperatures (when applicable)

Monitor for Alarm and Shutdown Indicators

Check that generator air inlet filter is clean, if applicable.




Generator Maintenance - Periodic After stopping the Generator Set for periodic maintenance

Periodic Maintenance time interval is based on Application

Reference respective OMMs

Must DOCUMENT and TREND data on each for future reference

Inspect generator for debris, foreign objects, leaks and loose connections, broken fittings, rubbing or damaged wiring, guards and components. Repair as necessary.

Inspect Main Stator & Rotor, Exciter, and PMG Clean as needed (Moisture, Salt, Dirt, Grease, Oil)

Reference SEHS9124 for Generator Cleaning and Drying

Check space heaters for proper operation.

Check Air Gap (main generator, exciter, & PMG)

Insulation Test (SEHS9124)




Generator Maintenance - Annual After Stopping The Generator Set

Must DOCUMENT and TREND data on each for future reference Complete Periodic Maintenance Procedures Alignment (LEBW4975, SEHS7654, SEHS7259, SEHS7073, REHS0177). Measure Generator Winding resistances (SENR5359 for SR4B, KENR5284 for

SR5) Main Stator/Rotor, Exciter Stator/Rotor, PM Stator/Rotor

Vibration Levels (LEBW4972) Generator Bearings and Wear Sleeves

Grease Bearing(s) as required Refer to REHS4892 for greasing requirements Avoid over-greasing/mixing greases and use correct grease

Check for good integrity of lip seal Inspect and clean all main current carrying mechanical contacts such as

circuit breakers and transfer switches




Generator Maintenance - Monitoring Recommendations

Trending

Understand the monitored process

Normalized readings For all resistance readings, correct for temperature

Refer to SEHS9124

Record on chart

Focus on changes occurring over time

Scheduled repairs instead of unplanned downtime




Generator Maintenance - Monitoring Recommendations

Source: Graph taken and formatted from Stitch in Time (Megger, 2006)

Shown above is an example of regular insulation trending and the result of not acting ahead of time.

Time to schedule downtime and repair of the generator.




Generator Maintenance - Insulation Test Recommendations(References: OMM & SEHS9124)

When to Test Safety Testing Process Prepare for the Test Insulation Resistance Test

Perform the standard 30/60sec test at a minimum Polarization Index Test

Perform when unit is in storage and/or moist environment.




Generator Maintenance - Bearing Temperature Guidelines

Bearing Temperature Set-points All Applications Alarm 85 C Shutdown 95 C

Exceptions exist in specific SR5 product using synthetic grease. For 1800/3000 frame, set-points are:

Alarm 95 C Shutdown 105 C

Temperature is affected by ambient but max settings are not! Generators shipped with Platinum 100 ohm RTDs

Packages can be ordered with bearing RTDs RTDs are 2-wire

Track and investigate any change from historical trend




Generator Maintenance - Bearing Replacement Removing Hub and Bearings

When applicable, heat front drive hub evenly with two (2) rosebud torches with propylene gas and puller or use destructive method (ie. cutting tool, etc.) to remove hub with care not to damage rotor shaft.

Heat should be applied to the hub for approximately 5-6 minutes.Do not attempt to heat hub with one (1) torch, and forcibly pull off shaft. Puller and ram drive should be capable of supplying at least 35 tons of force.

Refer to respective SOTA manual for further bearing removal instructions using specified tools.

Installing Hub and Bearings Use an induction heater, etc. to heat the ball bearings to recommended temperature and mount to the shaft. When applicable, evenly heat the drive hub to specified temperature and mount the hub to the shaft.

Reference respective generator SOTA manual for more bearing installation and removal information.




Generator Maintenance - Stator Temperature Guidelines Stator Temperature Set-Points

Alarm 180 C, Shutdown 190 C (Standby) Alarm 155 C, Shutdown 165 C (Prime/Continuous)

Exceptions exist for SR5 product Alarm 200 C, Shutdown 215 C, (Standby) Alarm 175 C, Shutdown 200 C, (Prime/Continuous)

Based on NEMA standards, it is recommended to stay below the alarm set-points to prevent winding deterioration.

Generators with Form Wound Stators shipped with Platinum 100 ohm RTDs Random Wound Packages can be ordered with stator RTDs RTDs are 3-wire for compensation accuracy

Track and Investigate any Change from historical trend Output Limited by Rotor or Stator Temp. Temp. Rise Function of Generator Output Measurement Method

Embedded Detector Rise by Resistance The standard, must add hot spot allowance

Refer to IEEE 112-1996 (Section 8.3.3)




Generator Maintenance - Vibration Measuring Guidelines

Measure on package at normal operating temperature

Use monthly readings to establish baseline

Vibration levels are load dependent

Investigate significant changes

New frequencies showing up

Increasing amplitudes of original frequencies

To accurately compare to factory guidelines per LEBW4972, vibration tool used must be factory approved.

Alternate tools can be used for site-specific trending purposes, but comparison to factory guidelines cannot be relied upon.

New factory tool is currently being validated to replace the previously available CSI Vibration Analyzer Tool.




SEHS9124 Generator Cleaning and Drying

Existing document updated to improve wording and emphasize Polarization Index (PI) test for testing generators in storage and/or moist environments.

REHS4892 Generator Bearing Service

Special Instruction published in early 2010 to update the latest bearing maintenance recommendations.

Single and Double-shielded bearings are recommended for greasing at prescribed intervals. Research has shown grease does penetrate the shield when the bearing bracket cavity is 50% full.

Bearing Change for 1800/3000 SR5 Generators In late 2011, these generators will be packaged with greaseable (2S-3230

grease) single-shielded bearings in place of non-greaseable synthetic grease double-shielded bearings.

This allows the end-user to add new grease as the grease breaks down over time.

Generator Maintenance Important Updates




Generator Maintenance - Literature

SEBD9205 Proper Storage of Generators SEHS9031 Storage Procedures for Caterpillar Products SEHS9124 Cleaning and Drying of Generators LEXE0095 Electric Power Start-up Checklist LEBW4975 Alignment A&I Guide SEHS7654 Alignment - General Instructions SEHS7259 Alignment of Single Bearing Generators SEHS7073 Alignment of Two Bearing Generators REHS0177 Alignment of Two Bearing Close-Coupled Generators LEBW4972 Linear Vibration A&I Guide SEBU7270 SR4/SR4B High Voltage OMM SEBU6042 Maintenance for Standby Gensets




Generator Maintenance Literature, cont.

SEBU6918 SR4B Generator OMM SENR7968 SR4 Generator SOTA Manual KENR5284 SR5 Generator SOTA Manual SENR5359 SR4B Generator Service Manual SENR5833 Digital Voltage Regulator Service Manual RENR2480 VR6 Service Manual RENR7941 CDVR Service Manual REHS4892 Generator Bearing Service REHS4634 Grounding Design Guide for EPG Products

Generator Maintenance

Documents

required maintenance

inelectric powerpage

product life shipping

beforeduringafter storage

shipping damages

longer storage

beforeafter shipping

improper shipping