NSP712 Diff.protection English Version

Nanjing Sino-German Protection & Substation Control System Ltd.

NSP712

Transformer Differential Protection

Technical Instruction

Nanjing Sino-German Protection & Substation Control System Ltd.

January 2007

* These instructions apply to NSP712 V3.00 and above versions. * These instructions and the product may be updated. Please check consistency between

actual product and version of instructions.

Table of Contents

1 SCOPE........................................................................................................................................................... 1

2 FEATURES ................................................................................................................................................... 2

3 TECHNICAL DATA .................................................................................................................................... 3

3.1 RATED DATA............................................................................................................................................. 3 3.2 POWER CONSUMPTION............................................................................................................................. 3 3.3 MAIN TECHNICAL FIGURES...................................................................................................................... 3 3.4 INSULATION PERFORMANCE .................................................................................................................... 4 3.5 ELECTROMAGNETIC INTERFERENCE RESISTANCE ................................................................................... 4 3.6 MECHANICAL PERFORMANCE.................................................................................................................. 5 3.7 AMBIENT CONDITIONS ............................................................................................................................. 5

4 PRINCIPLE OF PROTECTION................................................................................................................ 6

4.1 AC INPUT ................................................................................................................................................. 6 4.2 SOFTWARE DESCRIPTION ......................................................................................................................... 6 4.3 DIFFERENTIAL PROTECTION .................................................................................................................... 7 4.4 NSP712 UNDER VOLTAGE OR OVER NEGATIVE SEQUENCE VOLTAGE BLOCK AND OVER CURRENT

PROTECTION ................................................................................................................................................ 12 4.5 NSP712 ZERO SEQUENCE VOLTAGE PROTECTION ................................................................................ 12 4.6 NSP712 OVERLOAD ALARM.................................................................................................................. 13 4.7 DEVICE ALARM...................................................................................................................................... 13

5 NSP712 SYSTEM PARAMETERS AND SETTING LIST .................................................................... 14

6 USE OF MAN-MACHINE INTERFACE ................................................................................................ 19

6.1PANEL LAYOUT ....................................................................................................................................... 19 6.2 BUTTONS................................................................................................................................................ 19 6.3 SIGNAL LAMP AND LCD ........................................................................................................................ 20 6.4 SERIAL INTERFACE................................................................................................................................. 20 6.5 MENU STRUCTURE................................................................................................................................. 21 6.6 FUNCTIONS AND MENU.......................................................................................................................... 22 6.7 OPERATION INSTRUCTIONS .................................................................................................................... 23

7 DEBUGGING GUIDELINE...................................................................................................................... 27

7.1 DEBUGGING PRECAUTIONS.................................................................................................................... 27 7.2 CHECK BEFORE ENERGIZING THE DEVICE ............................................................................................. 27 7.3 INSULATION CHECK ............................................................................................................................... 27 7.4 ENERGIZING CHECK............................................................................................................................... 27

7.5 SAMPLING ACCURACY CHECK............................................................................................................... 27 7.6 SWITCH SIGNAL INPUT CHECK .............................................................................................................. 27 7.7 RELAY CONTACT TEST ........................................................................................................................... 28 7.8 SETTING TEST ........................................................................................................................................ 28 7.9 PROTECTION FUNCTION TEST ITEMS ..................................................................................................... 28

8 DEVICE OPERATION.............................................................................................................................. 29

8.1 NORMAL OPERATION STATUS OF DEVICE .............................................................................................. 29 8.2 INSTALLATION PRECAUTIONS ................................................................................................................ 29 8.3 DEVICE INFORMATION MEANING AND TROUBLE-SHOOTING................................................................. 29 8.4 EXAMPLE OF FAULT INFORMATION ........................................................................................................ 30

9 STORAGE................................................................................................................................................... 32

10 ORDERING INSTRUCTIONS............................................................................................................... 33

ANNEX........................................................................................................................................................... 34

ANNEX 1 NSP712V3.0 INFORMATION TABLE AND SUBMITTED MEASUREMENT........................................ 34 ANNEX 2 NSP712V3.0 TRANSFORMER DIFFERENTIAL PROTECTION DEVICE SETTING CALCULATION ..... 35 ANNEX 3 TERMINAL LAYOUT ...................................................................................................................... 39 ANNEX 4 TERMINAL WIRING DIAGRAM ...................................................................................................... 40 ANNEX 5 OPENING DIMENSIONS ................................................................................................................. 42 ANNEX 6 ORDERING NUMBER..................................................................................................................... 43

NSPS NSP712 Transformer Differential Protection Technical Instruction

1 Scope

The NSP712 series differential protection applies to 2-winding transformer and 3-winding transformer with voltage level of 220kV and lower, and can satisfy the requirements for four-side differential.

Schematic Figure for three-side or four-side transformer differential by NSP712 is shown in Figure1-1.

*

●

● I2

Y

△

*

* I1 ●

I3

Y

●

Y

△

*

*I1●

I2

*●

I3

*

●

● I3

Y

△

*

*I1 ●

I2

*●

I4

Y

Figure 1-1. Wiring schematic Figure for transformer differential

NSP712 features functions such as High-set Value Differential Protection, Ratio Differential Current Protection, Under Voltage or Over negative Sequence Voltage Block and Over Current Protection, Zero Sequence Voltage Protection, Over Load Protection and TA Fault Judgment. The Ratio Differential Current Protection in NSP712 device uses 2nd harmonic ratio.

NSP712A features functions such as High-set Value Differential Protection, Ratio Differential Current Protection, TA Fault Judgment, non-electric quantity protection. The Ratio Differential Current Protection in

SP712A device uses 2nd harmonics restraint ratio. N

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2 Features

Hardware platform with high-performance 32-bit DSP+ARM dual-processor as the core, which is

reliable and effective;

Use software adjustment, automatic TA matching and vector conversion;

Use reliable Id>Blk.by TA Fault criteria, making sure the device will not have wrong action in the event

of TA Fault or AC loop fault.

User friendly LCD, Chinese man-machine interface, and the operation is easy.

The protection action process is transparent, the information recording is complete, and use continuous ware recording method, which can record 6 waves maximum, each recorded wave lasts up to 4 seconds, providing complete Sequence of Event information;

Four value sets, which can be easily copied and set, for shifting use during change of operation mode;

Provide testing and analysis software NCP-Manage, which is based on WINDOWS interface, and

significantly increases the testing and maintenance efficiency, and can easily analyze the event and

wave;

Provide maximum 3 high-speed Ethernet ports as interface for automatic communication, and also can

provide dual 485 communication interface;

Multiple clock synchronization methods: communication synchronization, Pulse Per Minute

synchronization and IRIG-B code synchronization.

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3 Technical Data

3.1 Rated Data

DC power supply: 220V or 110V, permissible deviation +20%~-20% AC voltage: 100V or 57.7V AC current: 5A or 1A Frequency: 50Hz

3.2 Power Consumption

AC voltage: ＜0.5VA/phase AC current: ＜1VA/ phase (In=5A)

＜0.5VA／phase (In=1A) DC: Normal＜15W

Action＜25W

3.3 Main Technical Figures

3.3.1 Differential Protection Ratio Differential Current Pick-up Value: 0.10Ie~2.00Ie (Ie is rated current of transformer, same below) Differential instantaneous trip: 1.00Ie~20.00Ie Ratio Differential Current Starting Slope: 0.00~0.80 Ratio Differential Current Maximum Slope: 0.20~1.20 2nd Harmonic Restraint Ratio Coefficient: 0.10~1.00 Ratio Differential Action Time: ≤ 35 ms (2 times of setting value) Differential Instantaneous Trip Action Time: ≤ 25ms (1.5 times of setting value) Ratio Differential Current Setting Error: ±5% or ±0.01Ie Differential Instantaneous Trip Setting Error: ±5%

3.3.2 Under Voltage or Over negative Sequence Voltage Block and Over Current Protection Over Negative Sequence Voltage Setting Value: 1.00V~60.00V Under Voltage Setting Value: 10.00V~100.00V Current Setting Value: 0.10A~100.00A Time Delay Setting Value: 0.00~100.00s Voltage Setting Value Error: ±5% or ±0.05V Current Setting Value Error: ±5% or ±0.01In(In is TA Rated Second Current, same below) Time Delay Setting Value Error: ±1% setting value ± 40ms

3.3.3 Over Zero Sequence Voltage Protection Zero Sequence Voltage Setting Value: 2.00V~100.00V Time Delay Setting Value: 0.00~100.00s Voltage Setting Value Error: ±5% or ±0.05V Time Delay Setting Value Error: ±1% setting value ± 40ms

3.3.4 Over Load Protection Current Setting Value: 0.10A~100.00A Time Delay Setting Value: 0.00~100.00s

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Current Setting Value Error: ±5% or ±0.01In Time Delay Setting Value Error: ±1% setting value ±40ms

3.4 Insulation Performance

3.4.1 Insulation Resistance Use megohmmeter with 500V open circuit voltage to measure the insulation resistance between the energized

section and non-energized section and the casing, as well as between the loops without electrical connections, and under normal testing atmospheric conditions, the insulation resistance between the loops of each level should not be less than 20M. 3.4.2 Dielectric Strength

Under normal testing atmospheric conditions, the device can stand 1-minute power frequency withstand voltage test with a frequency of 50Hz and a voltage of 2000V, without flashover breakdown or element damage. During the test, when any tested loop is subject to voltage, the remaining loops will be equipotentially interconnected and earthed. 3.4.3 Impulse Voltage

Under normal testing atmospheric conditions, the loop to ground and between loops of the device can stand short-time impulse of 5kV, 1.2/50µs standard lightning wave. 3.4.4 Moisture and Heat Resistance

The device can stand testing temperature of 40℃±2℃ and relative humidity of 93%±3% in the constant temperature and humidity test specified in GB/T 2423.9, and the test duration is 48hr. 2 hours before the test is finished, measure the insulation resistance between the conductive circuits and the exposed non-energized part and between the loops without electrical connection according to Paragraph 3.4.1, which should not be less than 1.5 megohm. The dielectric voltage withstand strength should not be less than 75% of dielectric strength test voltage amplitude value specified in Section 3.4.2.

3.5 Electromagnetic Interference Resistance

3.5.1 Impulsive Interference The device can stand the interference test specified in GB/T 14598.13-1998. The testing power supply

frequency is 100kHz and 1MHz. Testing voltage is common mode 2500V, differential-mode 1000V decaying oscillation wave. During the test, subject the tested device to a power supply, and then overlap the interference test voltage according to the critical conditions listed in the table in Section 3.1.1 of GB/T14598.13, and the device will not act or reject the action. 3.5.2 Fast Transient Interference

The device can stand Class IV 40kV 10 fast transient interference test specified in GB/T 14598.10-1996. 3.5.3 Electrostatic Discharge

The device can stand Class IV (space discharge 15kV, contact discharge 8kV) electrostatic discharge test specified by GB/T 14598.14-1998 standard. 3.5.4 Radioactive Electromagnetic Field Interference

The device can stand radioactive electromagnetic field interference test with a Harsh Class III specified by GB/T 14598.9-1995. 3.5.5 Surge

Passed the Class III interference test (common mode 2000v, differential mode 1000V) for surge impact specified in GB/T 17626.5 1999.

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3.6 Mechanical Performance

3.6.1 Vibration The device can stand the vibration response test with a Harsh Class I specified in Section 16.2.3 of GB/T

7261-2000, Basic Testing Method for Relay and Equipment. 3.6.2 Shock

The device can stand the shock response test with a Harsh Class 1 specified in Section 16.4.1.1 of GB/T 7261-2000. The device can stand the shock durability test with a Harsh Class 1 specified in Section 16.5.1 of GB/T 7261-2000. 3.6.3 Impact

The device can stand the impact test with a Harsh Class 1 specified in Section 18.4 of GB/T 7261-2000.

3.7 Ambient Conditions

3.7.1 Ambient Temperature Working temperature: -10℃~+55℃ Storage temperature: -25℃~+75℃ At limit values, without being subject to energizing quantity, the device will not show irreversible changes,

and when the temperature returns to normal, the device can work normally. 3.7.2 Relative Humidity

Monthly average maximum relative humidity of the wettest month is 90%, and the monthly average minimum temperature of the month is 25℃, without surface condensation, and when the highest temperature is +40℃, the average maximum relative humidity will not exceed 50%. 3.7.3 Atmospheric Pressure

70-106kPa（below relative altitude above sea level of 2km）.

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4 Principle of Protection

4.1 AC Input

Input I1, I2, I3 three sides’ current, and (I1+I2+I3) forms the differential current, which will be the operating quantity of the differential relay. In this device, the phase difference existing between the current on each side of the transformer is automatically corrected by software. Current transformers on both sides use Y connection. The current reference direction on both sides directs to the protected equipment. Ua, Ub, Uc are taken from the low voltage side busbar TV, and are used as the Under Voltage Or Over Negative Sequence Voltage element for over voltage protection.

4.2 Software Description

The protection device normally performs communication, man-machine dialogue and other activities, and produces a sampling interruption at certain interval. The sampled parts go through digital filtering and pre-treating process through AD sampling, and form the quantities required for protection judgment. First, it will judge whether the differential element will be started, if so, it will first carry out the judgment of Differential Instantaneous Trip Protection. The action judgment for the Differential Instantaneous Trip Protection element is relatively simple; it essentially is a differential current over current relay, which does not require any surge current blocking judgment, TA fault judgment or TA saturation judgment. Then it goes to TA fault transient judgment procedure, if it is not TA fault, then it goes to the surge current judgment software, so as to differentiate whether it is a fault or excitation surge current. If it is not blocked by the surge current judgment element, then after the high-value ratio differential element is started, the action can be exported. The ratio differential element will also go through the TA saturation judgment, if TA is not saturated, then after the high-value ratio differential element is started, the action can be exported. Then it will go through other protection judgment such as the over current protection. For overall flow chart of the protection see Figure 4-1.

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Figure 4-1

Sampling

Computation

Differential protection pickup

TA fault judgement

TA saturation judgement

Sampling interruption

Other protections

Action logic

Return to main program

Y

YN

Y

NY

N

High-value ratio differential judgment

High-set value differential current protection judgment

N

Surge current judgement

Ratio differential judgment

4.3 Differential Protection

4.3.1 Ratio Differential General Pickup Element The ratio differential protection of the device is provided with general pickup element. When the maximum

value of the three-phase differential current is larger than the differential current pickup setting value, the pickup element will act, and after action of the pickup element, it will be widened by 500ms, open the exit relay positive power supply. Protection enter the calculation program of ratio differential fault measurement. 4.3.2 Ratio Differential Element

Action characteristics of the ratio differential protection are shown in Figure 4-2, and it can reliably evade the unbalance current in the event of external fault. The differential protection can satisfy the three-side and four-side differential requirements. The ratio differential protections uses second harmonic restraint.

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Id

Id>>

Id> K1

K2

Kb1Ie Kb2Ie Ir

Figure 4-2. Action characteristics of ratio differential protection

Where: Id is the action current; Ir is the restraint current;

>dI is the differential current pickup value;

>>dI is the Differential Instantaneous Trip value; Kl, K2 are ratio differential restraint coefficient; Ie is Rated Second Current; Kb1Ie, Kb2Ie are starting points of the action characteristic curve, in which the shaded area is the protection

action area. The device uses three-polygon ratio differential principle, whose action formula is as follows:

）（ >> dd II IeKb1≤rI )eKb(1 1IIKII rdd −∗>>− ）（ Ie KbIeKb 21 ≤< rI

)Ie Kb(K2e)KbKb(1 212 −>−∗−>− rdd IIKII ）（ Ie Kb2>rIWhere,

321 III ++=dI or 4321 IIII +++=dI

( )3215.0 IIII r ++= or ( )43215.0 IIIII r +++=

For transformer differential protection, the currents on each sides will go through Y／△ adjustment and TA matching through software, and use full Y wire connection. The full Y wire connection method offers significant advantage in reducing the secondary load of the current transformer and in improving the working performance of the current transformer. 4.3.3 2nd harmonic restraint

In the NSP712 protection, the ratio differential protection uses the 2nd harmonic in the three-phase differential current as the criteria for excitation surge current blocking. The action formula is as follows:

φφ 12 dsetd IKI ∗>

Where:

φ2dI is the 2nd harmonic of A, B and C three-phase different current; is the corresponding φ1dI

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three-phase fundamental component differential current; is the 2nd harmonic restraint coefficient. setKThe protection uses phase-wise blocking and cross blocking self-adaptive method.

4.3.4 TA Saturation Blocking Principle To avoid potential malfunction of the steady-state ratio differential protection caused by TA transient state

and steady-state saturation in the event of external fault, the device uses the harmonic of current on each side as the criteria for TA saturation, which is expressed as follows:

φφφ

φφφ

133

122

**

IKIIKI

>

>

Where:

φ2I , are the 2nd and 3rd harmonic current of a phase on a side; is the first harmonic of the

corresponding phase current; , are ratio coefficient of the 2nd and 3rd harmonic. Whose logic Figure is

shown as following:

φ3I φ1I

φ2K φ3K

eII %201 >ϕ

ϕϕ 12 %10 II >

ϕϕ 13 %10 II >

eI

Where:

Imax is Any side Max Current;

is the fundamental of a phase in a side; φ1I

is the 2nd harmonic of the corresponding phase; φ2I

is the 3φ3I rd harmonic of the corresponding phase.

Figure 4.3. TA saturation judgment logic Figure

Note: when TA is saturated, if there is current in one side TA, it will not block the differential. There must be at least one phase of current on each of both sides before the ratio differential is blocked. 4.3.5 High-value Ratio Differential Principle

To avoid time delayed action of the ratio differential caused by TA saturation and other factors in the event of serious fault in the area, the device is provided with a high ratio and high pickup value ratio differential protection, using its ratio restraint characteristics to resist the TA transient and steady-state saturation in the event of external fault, when in the event of TA saturation in internal fault, it can act reliably and correctly. The action formula of steady-state high-value ratio differential is expressed as follows:

)6.1(2.1 3 ered IIKII −+> er II 6.1>Where:

3K is the high-value ratio differential restraint coefficient, normally take 0.6-0.8, this device takes 0.75, in

which, the selection of differential current and restraint current are same as above. In the program, judgment is made for each phase one by one, and when above conditions are met, the ratio

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differential will act. Note: parameters of each phase of high-value ratio differential are set internally by the device (setting by user

is not necessary). 4.3.6 Differential Instantaneous Trip Protection

Differential instantaneous trip protection is essentially an over current relay reflecting the differential current, to ensure quick action trip in the event of serious fault inside of the transformer. When the differential current of any phase exceeds the Differential instantaneous trip setting value, action will happen immediately on the exit relay, and the typical exit action time is less than 25ms. 4.3.7 TA Fault Alarm Function

1) Time-delay TA Fault Alarm Function Time-delay TA fault alarm happens in the protection of sampling program. When the following two

conditions are met at the same time, and the time exceeds 2.5s, it will send TA fault alarm signal, but it will not block the ratio differential protection. This also plays a self-checking function to protect the AC sampling loop of the device. When any of the following conditions is not satisfied, and the time exceeds 5s, the TA fault alarm signal will be returned.

a) Negative sequence current on a side satisfies: ecba IIIIMaxI 01.0},,{25.02 +×≥ ;

b) At least one phase of the side has a current of zero.

ecba IIIIMaxI 01.0},,{25.02 +×≥

Figure 4.4 Time-delay TA fault judgment logic Figure

2) Transient TA Fault Alarm Function Transient TA fault alarm happens after pickup of the differential protection. When all following conditions

are met, TA on this side is considered transient fault: a) Maximum phase current of this side before pickup is larger than 0.12Ie; b) Maximum phase current of each sides after pickup is lower than 1.2Ie； c) After pickup, the current of any side is not increased from before pickup; d) At least one phase current on this side is zero (i.e. less than 0.06Ie) after pickup, and larger than 0.12Ie

before pickup. Entering the transient TA fault judgment program only after action of the ratio differential element, this also

prevents the wrong blocking of transient TA fault. Through setting control word selection, after transient TA fault judgment action, the ratio differential protection output can be blocked.

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Figure 4.5. Transient TA fault judgment logic Figure

4.3.8 NSP712 Series Differential Protection Logic Figure

Figure 4.6 NSP712 differential protection logic figure

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4.4 NSP712 Under Voltage or Over negative Sequence Voltage Block and Over Current Protection

The device is provided with two-stage under voltage or over negative sequence voltage block and over current protection respectively on the HV and MV sides. The under voltage or over negative sequence voltage element is comprised of interphase LV and negative sequence voltage or gate, using two control words to control the over current stageⅠ and stage II blocked by under voltage or over negative sequence voltage. When the under voltage or over negative sequence voltage block and over current protection control word is “1”, it means the over current protection of the stage is blocked by the under voltage or over negative sequence voltage. The current and time setting values of each stage can be set separately, control words can be set respectively to control the switching of both stages.

Figure 4.7 NSP712 under voltage or over negative sequence voltage block and over current protection

logic Figure

4.5 NSP712 Zero Sequence Voltage Protection

The device is provided with two-stage zero sequence voltage protection. A separate virtul linking piece is provided to control the switch of the protection.

Figure 4.8 NSP712 zero sequence voltage protection logic Figure

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4.6 NSP712 Overload Alarm

The device is provided with two-stage overload protection. A separate virtul linking piece is provided to control the switch of the protection.

Figure 4.9 NSP712 overload protection logic Figure

4.7 Device Alarm

When hardware fault in the device is detected, device abnormal signal will be sent, and the whole protection will be blocked. Hardware fault includes: RAM, EPROM, setting value error, etc.

When following faults are detected, alarm signal will be sent. 1) TV fault alarm When any of the following conditions is satisfied for more than 2.5s, the “TV fault” signal will be sent.

When both of the following conditions are not satisfied for more than 5s, the “TV fault return”. There is current in at least one phase and >0.12In, positive sequence phase voltage<10V. Negative sequence phase voltage >10V.

2) TA fault alarm (see 4.3.7) 3) When 2nd harmonic blocking ratio differential signal has occurred.

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5 NSP712 System Parameters and Setting List

System Parameter Parameter Description Byte Range Step

TATV Parameter 1 Differential Type 2 Two-side/three-side ----- 2 Transformer Capacity 2 0-1000.0 MVA 0.1 MVA3 Rated Primary Voltage of Side1 2 1.00-600.00 kV 0.01 kV4 Rated Second Voltage of Side1 2 0-100.00 V 0.01 V 5 Rated Primary Current of Side1 2 0-60000 A 1A 6 Rated Second Current of Side1 2 1A/5A ----- 7 Rated Primary Voltage of Side2 2 1.00-600.00 kV 0.01 kV8 Rated Second Voltage of Side2 2 0-100.00 V 0.01 V 9 Rated Primary Current of Side2 2 0-60000 A 1A

10 Rated Second Current of Side2 2 1A/5A -----

11 Vector Group side2 to side1 2

12 o’clock wiring/11 o’clock wiring without earthing/11 o’clock wiring with earthing / /1

o’clock wiring without earthing/1 o’clock wiring with earthing

-----

12 Rated Primary Voltage of Side3 2 1.00-600.00 kV 0.01 kV13 Rated Second Voltage of Side3 2 0-100.00 V 0.01 V 14 Rated Primary Current of Side3 2 0-60000 A 1A 15 Rated Second Current of Side3 2 1A/5A -----

16 Vector Group side3 to side1 2

12 o’clock wiring/11 o’clock wiring without earthing/11 o’clock wiring with earthing / /1

o’clock wiring without earthing/1 o’clock wiring with earthing

-----

17 Rated Second Voltage of TV Zero Sequence 2 0-100.00 V 0.01 V Binary Input Parameter

18 Binary Input 1filter Time 2 10-32767 1ms 19 Binary Input 2filter Time 2 10-32767 1ms 20 Binary Input3 filter Time 2 10-32767 1ms 21 Binary Input 4filter Time 2 10-32767 1ms 22 Binary Input5 filter Time 2 10-32767 1ms 23 Binary Input6 filter Time 2 10-32767 1ms 24 Binary Input 7filter Time 2 10-32767 1ms 25 Binary Input8 filter Time 2 10-32767 1ms 26 Binary Input 9filter Time 2 10-32767 1ms 27 Binary Input10 filter Time 2 10-32767 1ms 28 Binary Input 11filter Time 2 10-32767 1ms 29 Binary Input12 filter Time 2 10-32767 1ms 30 Binary Input13 filter Time 2 10-32767 1ms 31 Binary Input14 filter Time 2 10-32767 1ms

Clock Synchronization Mode

32 Clock Synchronization Mode 2 Communication synchronization/ Pulse Per Minute + communication/IRIGB code -----

Report Management 33 Save Report？ 2 Save/Note save -----

Password Information 34 User Password1 2 0-8 1 35 User Password2 2 0-8 1 36 User Password3 2 0-8 1 37 User Password4 2 0-8 1 38 User Password5 2 0-8 1 39 User Password6 2 0-8 1

RS485 Communication Parameter

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40 RS485 Address 2 0-255 41 RS485A Baud 2 1200/2400/4800 9600/19200 42 RS485A Check Mode 2 none/odd/even check 43 RS485B Baud 2 1200/2400/4800 9600/19200 44 RS485B Check Mode 2 none/odd/even check 45 RS485A Channel 2 0-4 46 RS485B Channel 2 0-4

EtherNet Communication Parameter 47 EtherNet Port A IP Address 4 ------ ------- 48 EtherNet Port A Port Number 2 0-65535 1 49 EtherNet Port A Subnet Mask 4 ------ ------- 50 EtherNet Port A Remote IP Address 4 ------ ------- 51 EtherNet Port A Remote Port Number 2 0-65535 1 52 EtherNet Port A Remote IP Port Number 2 0－6 1 53 Local MAC 6 ---- ----

The number of EtherNet Port A IP Address, Port Number and Channel is most 8 Parameters of EtherNet Port B and C are the same as that of Port A

Protection Function Configuration 54 Transformer Differential Protection 2 Open/Close -----

55 Under Voltage or Over negative Sequence Voltage Block and Over Current Protection of Side1 2 Open/Close -----

56 Under Voltage or Over negative Voltage Block and Over Current Protection of Side2 2 Open/Close -----

57 Over Zero Sequence Voltage Protection 2 Open/Close ----- 58 Over Load Protection 2 Open/Close ----- 59 TA Fault Check 2 Open/Close ----- 60 TV Fault Check 2 Open/Close -----

Only the protection function is configured before the corresponding protection setting menu can be entered. If it is not configured, DSP program internal processing can not access the corresponding protection program module, it can only access the initial

function of the protection module. Current Valid Value Set

61 Current Valid Value Set 1 0x0017-0x1a(A-D) Protection Setting

Differential Protection

62 Switch of High-set Value Differential Current Protection 2 On/Off -----

63 Switch of Ratio Differential Current 2 On/Off ----- 64 Ratio Differential Protection Blocked by CT Fault 2 On/Off ----- 65 High-set Value of Differential Current 2 1.00 – 20.00 Ie 0.01Ie 66 Ratio Differential Current Pick-up Value 2 0.10 – 2.00 Ie 0.01Ie 67 Ratio Differential Current Strating Slope k1 2 0.00- 0.80 0.01 68 Ratio Differential Current Strating Slope k2 2 0.20 – 1.20 0.01 69 k1 Base point 2 0.00 – 2.00 0.01 70 k2 Base point 2 0.00 –5.00 0.01 71 2nd Harmonic Ratio Coefficient 2 0.1 – 1.00 0.01

Under Voltage or Over negative Sequence Voltage Block and Over Current Protection of Side1 72 Switch of Over Current Stage of Side1Ⅰ 2 On/Off -----

73 Over Current Stage Blocked by Under Voltage or ⅠOver negative Sequence Voltage of Side1 2 On/Off -----

74 Switch of Over Current Stage of Side1Ⅱ 2 On/Off -----

75 Over Current Stage Blocked by Under Voltage or ⅡOver negative Sequence Voltage of Side1 2 On/Off -----

76 Switch of Over Current Blocked by CT Fault 2 On/Off ----- 77 Negative Sequence Voltage Setting Value 2 1.00 – 60.00V 0.01V 78 Under Voltage Setting Value 2 10.00 –100.00V 0.01V 79 Over Current Stage Setting Value of Side1Ⅰ 2 0.10 –100.00A 0.01A 80 Time-delay Over Current Stage of Side1Ⅰ 2 0.00 – 100.00s 0.01s 81 Over Current Stage Setting Value of Side1Ⅱ 2 0.10 –100.00A 0.01A

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82 Time-delay Over Current Stage of Side1Ⅱ 2 0.00 – 100.00s 0.01s Under Voltage or Over negative Sequence Voltage Block and Over Current Protection of Side2

83 Switch of Over Current Stage of Side2Ⅰ 2 On/Off -----

84 Over Current Stage Blocked by Under Voltage or ⅠOver negative Sequence Voltage of Side2 2 On/Off -----

85 Switch of Over Current Stage of Side2Ⅱ 2 On/Off -----

86 Over Current Stage Blocked by Under Voltage or ⅡOver Negative Sequence Voltage of Side2 2 On/Off -----

87 Over Current Protection Blocked by TV Fault 2 On/Off ----- 88 Over Negative Sequence Voltage Setting Value 2 1.00 – 60.00V 0.01V 89 Under Voltage Setting Value 2 10.00 –100.00V 0.01V 90 Over Current Stage Setting Value of Side2Ⅰ 2 0.10 –100.00A 0.01A 91 Time-delay Over Current Stage of Side2Ⅰ 2 0.00 – 100.00s 0.01s 92 Over Current StageⅡSetting Value of Side2 2 0.10 –100.00A 0.01A 93 Time-delay Over Current Stage of Side2Ⅱ 2 0.00 – 100.00s 0.01s

Zero Sequence Voltage Protection 94 Switch of Zero Sequence Voltage StageⅠ 2 On/Off ----- 95 Switch of Zero Sequence Voltage StageⅡ 2 On/Off ----- 96 Zero Sequence Voltage StageⅠ 2 2.00 –100.00 V 0.01V 97 Time-delay of Zero Sequence Voltage StageⅠ 2 0.00 – 100.00s 0.01S 98 Zero Sequence Voltage StageⅡ 2 2.0 –100.00 V 0.01V 99 Time-delay of Zero Sequence Voltage StageⅡ 2 0.00 – 100.00s 0.01S

Over Load Protection 100 Switch of Over Load Alarm StageⅠ 2 On/Off ----- 101 Switch of Over Load Alarm StageⅡ 2 On/Off ----- 102 Switch of Over Load Alarm StageⅠ 2 0.10 –100.00 A 0.01A 103 Time-delay of Over Load Alarm StageⅠ 2 0.00 – 100.00s 0.01s 104 Over Load Alarm Stage ValueⅡ 2 0.10 –100.00 A 0.01A 105 Time-delay of Over Load Alarm StageⅡ 2 0.00 – 100.00s 0.01s

Note:

1 Wiring method 1) TA is connected in full Y type, Y／Δ switching is done by the program. 2) If the protection only uses current on two sides, only need to set the “Differential Type” to “two-side”, and

the “System Parameter” automatically displays the system parameters for differential on both sides. Current connection to side 1 and side 2 will realize the two-side differential, no need to short the side 3 terminal. For example: for a Y/△-11 two-winding transformer, only need to realize two-side differential, connect the HV side TA to side 1, and the LV side TA to side 2. Set the “Differential Type” in the “System Parameter” to “two-side”, and according to the wiring method table, select “11 o’clock wiring without earthing” or “11 o’clock wiring with earthing” for the “Vector Group side2 to side1”.

2 Electric quantity adjustment for each side of the transformer The secondary wiring for current transformer on each side of the transformer all uses Y type connection. The

secondary current is directly connected to the device. Through the transformer capacity, the setting of rated voltages on each side of the transformer and the TA transformation ratio on each side and the wiring method, the device automatically adjusts the TA secondary current phase on each side of the transformer. We take the following two-side differential as an example to demonstrate the adjustment of current value and phase for NSP712.

1） Setting Side 2 to Side 1 to “12 o’clock wiring” Before the side 1 and side 2 three-phase current is taken into the calculation of differential current and

restraint current, perform the zero operation first, whose modified formula is as follows:

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*01

**' III AA −= ；；；（1） *01

**' III BB −= *01

**' III CC −=*02

**' III aa −= ；；（2） *02

**' III bb −= *02

**' III cc −=

Where： *AI , , are per unit valve of TA secondary current of side 1; *

BI *CI

*'AI , , are the per unit value of current of each phase after modifying side 1; *'

BI *'CI

3/)( ****01 CBA IIII ++= is the per unit value of calculated zero sequence current of side 1; *aI , , are per unit valve of TA secondary current of side 2; *

bI *cI

*'aI , , are the per unit value of current of each phase after modifying side 2;

is the per unit value of calculated zero sequence current of side 2;

*'bI *'

cI 3/)( ****02 cba IIII ++=

The obtained , , and , , are taken into the calculation of differential current and restraint

current. For details of calculation formula, please refer to Section 4.3.2.

*'AI *'

BI *'CI *'

aI *'bI *'

cI

2） Setting Side 2 to Side 1 to “11 o’clock wiring without earthing” The device uses Δ->Y change to adjust the differential current balance. The first side is Y side, no adjustment,

and adjustment is made for Δ side current as follows:

3/)( ***'caa III −= ; 3/)( ***'

abb III −= ; 3/)( ***'bcc III −= （3）

Where： *aI , , are per unit valve of TA secondary current on Δ side, *

bI *cI

*'aI , , are per unit values of each phase current after correction. *'

bI *'cI



*AI *

BI *CI *'

aI *'bI *'

cI

3） Setting Side 2 to Side 1 to “11 o’clock wiring with earthing” The device uses Δ->Y change to adjust the differential current balance. The first side is Y side, perform the

zero operation as in formula (1), for Δ side current perform phase adjustment same as formula (3).



*'AI *'

BI *'CI *'

aI *'bI *'

cI

4） Setting Side 2 to Side 1 to “1 o’clock wiring without earthing” The device uses Δ->Y change to adjust the differential current balance. The first side is Y side, no adjustment,

and adjustment is made for Δ side current as follows:

3/)( ***'baa III −= ; 3/)( ***'

cbb III −= ; 3/)( ***'acc III −= （4）

Where, *aI , , are per unit valve of TA secondary current on Δ side, *

bI *cI

*'aI , , are per unit values of each phase current after correction. *'

bI *'cI



*AI *

BI *CI *'

aI *'bI *'

cI

5） Setting Side 2 to Side 1 to “1 o’clock wiring with earthing” The device uses Δ->Y change to adjust the differential current balance. The first side is Y side, perform the

zero operation as in formula (1), for Δ side current perform phase adjustment same as formula (4).

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*'AI *'

BI *'CI *'

aI *'bI *'

cI

3 Save Report? Select “Yes” for normal operation and “No” is selected only when during testing and wish to save the original fault report, in this way, the original fault report will not be superseded.

4 “Remote IP”: this gives a list of IP addresses for physical ports of a remote host, each port has maximum 8 groups, and the device allows sending data to the IP addresses of remote host in the list. If not so many IP addresses are used, those unused IP addresses can be set to 0.0.0.0;

5 Physical channel and logic channel: in order to make the device adaptive to various network configurations of the communication system, the concept of physical channel and logic channel must be distinguished. The so called physical channel means actual channel of physical connection, such as the RS485A, RS485B, EtherNet Port A, EtherNet Port B and EtherNet Port C in the device. Such physical channels normally have some related settings, for example, RS485 has baud rate, start bit, data bit, stop bit and check bit, etc. EtherNet has MAC address, IP address, port number, etc. The so called logic channel is proposed considering the transmission and processing methods of information in the communication system. To handle the anomaly occurred during the channel and host operation, and increase the communication reliability of the system, the communication system normally uses redundancy configuration. A communication system normally has two or more communication channels or main/spare host backup. Considering the conciseness of data processing, during operation, normally one channel is used as the main channel and the other one as the hot spare channel, and in the event of failure in the main channel, switch to the spare channel by the host. In this way, for the above level data up loaded semi-voluntarily, it should make sure the same data will not be repeatedly reported in the same communication system during switching of channels. The solution to such problem is the use of the logic channel concept, i.e., assign the same logic channel to the communication system with redundant main/spare host, and the corresponding level of data have the same outquene pointer. Any host in the system requests one level of data from the host, the outquene pointer of the logic channel will add one.

6 “Logic channel of remote IP address”: if the functions of remote host are the same, they can be set to the same logic channel number, for example, the channel numbers of main front host and spare front host are set to 0, and the channel number for protection administration host is set to 1.

7 Notes on protection setting 1) Start value of ratio differential element normally takes 30% of the rated current of the transformer. 2) Differential instantaneous trip element is set according to the unbalanced current of the severest external

fault and current transformer saturation and evading the transformer’s excitation surge current. 3) Note on control word during protection operation The operation mode control word is entered during setting of values, used for switching of protection

operation functions. In which, when the blocking control word of “TA fault blocking ratio differential” is on, once the instantaneous TA fault judgment element has acted, it will block the ratio differential protection exit port, and other protection elements will operate normally. On the other hand, if the control word of “TA fault blocking ratio differential” is set to “off”, then, after the instantaneous TA fault judgment element has acted, it will not block the ratio differential protection exit, and all protection elements will operation normally.

4）When “TV Fault Check” and “TA Fault Check” are on, once there is an alarm, it will produce alarm information and the alarm lamp will be on.

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6 Use of Man-Machine Interface

To make the operation easy, the device is provided with a functional and flexible man-machine interface (MMI).

6.1Panel Layout

Layout of front panel of the device is shown in Figure 6-1:

Buttons

Big LCDdisplay in Chinese

Figure 6-1 Layout of device panel6.2 Buttons

There are 9 buttons on the panel: “▲”, “▼”, “◄”, “►”, “＋”, “－”, “Enter”, “Cancel” and “Reset”. Normally, the “Enter” button is used to go from one level of menu to its next level of menu, or to make a yes selection, while the “Cancel” button is used to return from one level of menu to its superior level of menu, or to make a no selection. “▲” and “▼” buttons are used to move the hand-shaped cursor up and down to highlight the submenu to be entered or the highlighting cursor to highlight data to be modified; the “◄” and “►” buttons are used to move the highlighting cursor to highlight one of the data to be modified; the “＋” and “－” buttons are used to change the data in the row/column where the cursor stays. The “Reset” button is used to reset the protection action lamp on the panel and reset of the signal relay.

The system has an automatic saving prompt function. Under the “System Parameter” and “Value Set X” menu, if a parameter or a value is changed, after pressing the “Cancel” button to return to the previous level menu, the system will automatically prompt to “save above change”? Press the “Enter” button to save the change, or press the “Cancel” button to quit the change.

The system has an information prompt function. When displaying large amount of information, multi-screen display is necessary. During the display, if the last line in the LCD has a “▼” sign, it means more information can be accessed with the “▼” button or “Enter” button. if the last line in the LCD has a “▲” sign, it means it can return to the previous information screen with the “▲” button or “cancel” button. The last line also displays the current page and the total number of pages.

To avoid misoperation, the device is provided with a 6-digit user password. When it prompts to enter the

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password, the correct password must be entered to obtain the operation authorization. During entering of the password or prompt of “wrong password” or “wrong time overlimit”, the “Cancel” button can be used to cancel the entering of password and return to the menu before entering the password. When it prompts “wrong password”, press “Enter” button to continue with the entering of password till the password is correct or wrong number overlimit. The default password is 6“▲”’s.

If the system prompts “operation failed”, press the “Cancel” button to return to the previous level of menu.

6.3 Signal Lamp and LCD

The panel is provided with 7 LED indication lamps, as follows: “Run” lamp is green color, and flashes once per second during normal operation of the device;

Run

Abnormal

Differential

Over Current

Zero Voltage

Over Load

Alarm

“Abnormal” lamp is red color, which will be on when anomaly is discovered during self-checking of the device; “Differential” lamp is red color, which will be on when the differential protection action trips, and will not be off till the “Reset” button is pressed; “Over Current” lamp is red color, which will be on when the over load protection action trips, and will not be off till the “Reset” button is pressed; “Zero Voltage” lamp is red color, which will be on when the zero sequence voltage protection action trips, and will not be off till the “Reset” button is pressed; “Over Load” lamp is red color, which will be on when the over load acts, and will be automatically off when the over load returns; “Alarm” lamp is red color, which will be on when anomaly is discovered in the system operation, such as TV fault, 2nd harmonic blocking, and will be automatically off when the anomaly returns to normal.

The device is provided with a big LCD displaying in Chinese. The LCD is provided with backlighting, which will be off when no button is operated for a long time. Once the button is operated, the backlight will be automatically on.

6.4 Serial Interface

The maintenance port on the panel of the device is DB9 hole type socket, which is defined as follows:

Table 15. Definition of Maintenance Port Socket

Socket No. Definition

2 RXD

3 TXD

5 GND

Use a communication cable shown in Figure 6-2 to connect the device to a PC, and use the NCP-Manager maintenance software to perform maintenance on the device, note that the maintenance port transmission baud rate is fixed at 9600.

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Figure 6-2. Connection between PC and Maintenance Port

接装置接PC机To PC To device

6.5 Menu Structure

The command menu uses the following tree type directory: 主菜单

实时信息

操作记录

帮助信息

手动校准

自动校准

具体保护…….

测量数据

遥信状态

通讯状态

调试工具

软件参数

装置说明

遥信事件

事件报告

故障报告

报告查询

开出传动

精度校准

计算参数

参数设定

保护定值

保护配置

TATV参数

遥信参数

通信参数

系统时间

对时方式

切换定值组

复制定值组

定值组A

定值组B

定值组C

定值组D

报告保存

修改密码

差动类型

Main menu

Parameter setting Differential type

Protection configuration

TATV parameter

Binary input parameter

Protection setting

Value set A

Value set B Communication

parameter Value set C

Value set D System time

Clock sync. mode Copy value set

Switch value setSave report

Specific protections …

Change password

Real-time information

Measurement data

Binary input status

Communication status Fault report

Calculation parameter Event report

Report queryBinary input

event

Precision calibrationOperation

record

Output transmissionDebugging

tool Manual calibration

Automatic calibration

Software parameter

Help information

Device description

Figure 6-3. Tree type menu structure

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6.6 Functions and Menu

6.6.1 Real-time Information This part of menu is mainly used to display some real-time refreshed measured values and status values,

including secondary sampling measured value, binary input status, communication status of the communication ports and the calculated rated current, etc.

（1）Secondary measured value This menu allows real-time display of many measured values and calculated values. It allows display of this

side phase voltage UA, UB, UC）, line voltage（UAB, UBC, UCA）, zero sequence voltage（own 3U0）, negative sequence voltage（U2）, each side current（Ia, Ib, Ic）, and angle of the analog values of the loops.

（2）Binary input status The binary input status allows real-time display status of all inputs of the device. （3）Communication status The communication status allows real-time display of the current communication status of the

communication channels of the device. （4）Calculation parameter The calculation parameter allows display of rated current values on each side of the transformer, and identify

whether the set of rated current is valid. 6.6.2 System Parameter

This menu is mainly used to display and change some parameters of the system. Differential type: set two-side or three-side differential according to the type of the protected transformer. Protection configuration: to configure the protection functions to be used, open and close the protection

modules. The closed protection function will not be seen in the value menu. TATV parameter: mainly used to set parameters for the protected transformer, each side TATV rated values

and wiring method, etc. This parameter should match with the actual parameter. Binary input parameter: to configure the binary input filtering time. Communication parameter: to set the parameters required by the communication methods provided by the

device, such as device address, RS485 baud rate, and EtherNet parameters. System time: to display time and local clock synchronization. Clock synchronization mode: to select the clock synchronization mode for the device. Save report: to set whether to save the fault report and record the fault wave. Change password: to change the user password.

6.6.3 Protection Setting This menu allows viewing, change, copy of the settings, and switching of valid value sets, etc.

6.6.4 Fault Report This menu allows viewing of 10 complete fault records, accurate display of related analog values during the

whole process for the protection from start, occurrence and elimination, which facilitates quick reference and analysis after an event. 6.6.5 Event Report

Event report mainly covers the following: Device self-checking information, process record for the protection action or alarm, etc. Totally 1,000 event reports can be recorded, in which the 000th is the latest information, and the 001st is the

next latest information, and so on. As there is a lot of event information, the report can be accessed directly by entering the serial number of the event report.

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6.6.6 Binary Input Event The binary input event records specific information of binary input change in each loop according to the time

order, which can record maximum 256 position change information, in which the 000th is the latest information, and the 001st is the next latest information, and so on. 6.6.7 Operation Record

The operation record mainly records the operations on the device through various ways (including main unit, maintenance port and buttons), such as change of setting or system parameter, output transmission, etc.

It totally can record 256 operation records, in which the 000th is the latest record, and the 001st is the next latest record, and so on. 6.6.8 Debugging Tool

The testing function mainly includes output transmission, manual calibration and automatic calibration. Output transmission: this menu is used to test the integrity of each exit loop, and also can be used to operate

the switch locally with buttons. Attention: this test may directly operate the switch, please operate with care. Make sure the corresponding switch is in the test position or not in the running state before operation!

Manual calibration: the device has been strictly tested and calibrated in the shop, so that calibration is not encouraged in the field, including manual calibration and automatic calibration. However, if anomaly has occurred, for example, separate change of CPU or TATV boards, calibration can be done. Manual calibration allows calibration of a specific analog channel.

Automatic calibration: is divided into voltage automatic calibration and each side current automatic calibration. It is required that rated analog value should be added on the voltage channel or each current channel before calibration. 6.6.9 Help Information

Software parameter: use can access the software parameters to know the authentic device model number and version of software, including DSP version number and MMI version number and the respective check code, so as to ensure unity and identity of the device. This parameter must be provided when the device is under maintenance or purchase of spare parts.

Device description: is the brief description of the device.

6.7 Operation Instructions

6.7.1 Menu Structure, Guide Path and General Operation Instructions When the device is energized, during normal operation, the LCD screen will display the main interface or the

menu for measured values. In the main interface, press “Enter” button to enter the main menu.

Menu

Main Menu **************** 01. Real-time information

Title Cursor

02. System parameter 03. Protection setting 04. Binary input event 05. Event report 06. Fault report 07. Operation record 08. Test function 09. Help information

The relationship between various menu levels refer to Figure 18 “Menu Tree Type Structure”. For operation,

press “▲” and “▼” buttons to move the cursor up and down to highlight the submenu to be entered, press “Enter” button to enter the corresponding submenu, press “Cancel” button to return to the previous menu level; the “◄”

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and “►” buttons are used to change the parameters or settings; to change the parameters, the password must be entered.

Differential Protection = = = = = = = = = =

Ratio Differential Current State Ratio Differential Current Pick-up

Value 0.20 Ie Ratio Differential Current Strating

Slope K1 0.30 Ratio Differential Current Max Strating

Slope K2 0.60

K1 Base point 1.00

K2 Base point 4.00

Highlight cursor

Setting content

Setting

6.7.2 Viewing and Change of Setting or Parameter Viewing: press the “▲” and “▼” buttons to move the cursor to select different function settings, highlight

the corresponding menu and press the “Enter” button to enter. Then you will see the corresponding contents. If a “▼” sign appears in the lower right corner of the screen, it means there is a next screen of settings. Use the “▼” button to move the cursor to the last line and go to the next screen. You can also press the “Enter” button to quickly switch between the screens. Similarly, if a “▲” sign appears in the upper left corner of the screen, it means there is a previous screen of settings. Use the “▲” and “▼” buttons to move the cursor to the top line and return to the previous screen. You can also press the “Cancel” button to quickly switch between the screens.

Change: when the corresponding menu or setting contents are highlighted, if you wish to change the setting or parameter, press the “＋” button or the “－” button. If you do not have the authorization to change the setting of the current function, the device will prompt to enter the password. Only by entering the correct password can you change the displayed settings. The authorization is valid only in the current setting module. During change of the setting or parameter, the system will perform dynamic boundary checking, once the changed value exceeds the range, the system will keep the original value unchanged, for range of settings, see “Setting List”. After the setting or parameter is changed, you may highlight the “save and exit” and press the “Enter” button to exit, then enter the password, and after the correct password is entered, press the “Enter” button, and the system will save all parameters or settings before return to the main menu interface. You may also press the “Cancel” button to return to the main menu, if the parameter is changed, the system will automatically prompt “save the change”, use the “Enter” button to confirm the saving, if you do not wish to save, press the “Cancel” button to return to the previous level of menu. 6.7.3 Measuring Value

Measuring value has multiple screens of information, use the “▲” and “▼” buttons to browse the screens. The displayed information is updated every one second. To easily view the measuring value, in the main interface, use the “▼” button to directly go to the measuring value interface. Press the “Cancel” button to return to the main menu interface.

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13:23:31.234· Phase A differential pick-up

Occur

002 2005-11-15

13:23:31.234· Phase A ratio differential action

Occur

001 2005-11-15

Phase A differential pick-up Cancel

13:23:32.234·

000 2005-11-15 = = = = = = =

6.7.4 View Report

Enter the corresponding report interface, the binary input change information, the recorded event information and operation record information will be displayed in the time order. Use the “▲” and “▼” buttons to browse all information in the screens. 6.7.5 Calibration Factor

Before the calibration factor, the precision signal source must be connected to the device according to the requirement, press the “Enter” button to enter the correct password, and then the system will automatically calibrate the factor. This function is mainly used in the in-shop debugging, and shall not be used in the field. 6.7.6 Change Password

Change password: the default password is 6 “▲”’s. When the password is changed, the new password must also be 6-button password, and the “Reset”, “Cancel” and “Enter” buttons can not be used in the password. If the password is changed successfully, the new word will come into effect, and when it prompts to enter the password, the new password must be entered. 6.7.7 Enter Password

When operation authorization is required, the system will prompt to enter the password. Take the example of saving system parameter:

When it is confirmed to save the system parameter, the system will ask to enter the password. After entering the password, press the “Enter” button. If the password is correct, the device will automatically return to the previous menu level, i.e., the main menu; if the password is wrong, the system will prompt “wrong password”. Press the “Enter” button to continue entering the password, till the wrong password is entered for three times. After the wrong password is entered for three times, the system will prompt “number of wrong password entered overlimit”, then only the “Enter” button or “Cancel” button can be pressed to quit the operation. When entering the password, press the “Cancel” button to quit. 6.7.8 Operation Failure Prompts

When saving the system parameter or setting, if the system prompts operation has failed, press the “Enter” button to return to the previous menu to view the report, analyze the cause of failure, and proceed with the next operation according to the contents of the event report. 6.7.9 Output Transmission

In the “Test Function” menu, enter the “Output Transmission” screen, use the “▲” and “▼” buttons to select

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the exit loop. After entering the correct password, the system will ask to “Confirm Transmission”, press the “Enter” button to realize the transmission, and press the “Cancel” button to quit the transmission of the current exit. After confirming the transmission, the corresponding exit relay will act for short-time, and then automatically returns.

Note: this test may directly operate the switch, please operate with care. 6.7.10 Automatic Popout of Event Report Interface by Protection Action

During operation of the device, if a new event (protection action event, etc.) has happened, the device will automatically light the LCD, and display the latest three events on the LCD screen. At this time, manual confirmation is required to return to the main interface screen, i.e., to view the information and press the “Cancel” button continuously to return.

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7 Debugging Guideline

7.1 Debugging Precautions

Read through this debugging guideline and related instructions before testing. Pullout/insertion of device modules should be minimized. Do not touch the module circuits or chips. Do not

pull out/insert the modules when energized. The electric iron or oscilloscope used must be reliably earthed to the panel cabinet. Before testing, check the panel cabinet and the device against any visible damage or loosening of screws

during transportation, particularly the screws and connecting pieces for TA loops. Any loosening is not allowed. Check the program version number and check code.

7.2 Check before Energizing the Device

Visual and wiring inspection: Mainly check the appearance of the protection device against any damage, and check the nameplate

parameters, marking and wiring against the design drawings. And check the workmanship of the device, and check the terminal against any loosening.

Check rated parameters of the power supply plug-in modules and AC plug-in modules, the trip current and switch-off current of the relay plug-in module against the actual requirements of the system.

Hardware jumper check: Configure and check the hardware according to the setting requirements.

7.3 Insulation Check

Connect the terminals of the device in parallel (insulation test for communication terminal is not necessary), and use 500V megameter to measure the insulation to the earth for the plug-in’s, and the insulation resistance should be larger than 20M.

7.4 Energizing Check

Energizing preliminary check is to check whether all the components are working normally after energizing, which mainly include the energizing self-check of the device, check of keyboard function, software version and program check code and the setting and checking of the clock. Enter the value sets according to the value list to the corresponding setting area, and switch to operate the setting area.

7.5 Sampling Accuracy Check

Enter the “Measuring Value” submenu in the “System Setting”, and on the protection panel end, add the rated voltage and current, and the sampled value on the LCD screen should be equal to the actually added value, and the error should be less than the related requirement.

7.6 Switch Signal Input Check

Enter the “Input Status” submenu, and on the switch signal input end of the device, add the excitation signal respectively, and check the conduction of the input loops, the input status displayed on the LCD screen should have corresponding change.

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7.7 Relay Contact Test

The relay contact test can also be done through the “Output Transmission” menu of the protection. Each loop of exit relay can be operated. For operation method refer to the description of operation menu. For testing of trip exit, closing loop, a closing transmission and a trip transmission should be done with the simulated circuit breaker to confirm the action of the circuit breaker.

7.8 Setting Test

The protection functions and action logic of the device have gone through multiple dynamic simulation test, type test and other tests. The field testing only needs to check the settings.

7.9 Protection Function Test Items

See Test Report for NSP712 Transformer Differential Protection Device.

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8 Device Operation

8.1 Normal Operation Status of Device

During normal operation of the device, the “Run” lamp should be on / off alternatively, and other indication lamps should be off.

In the event of interruption in the communication between the administration CPU and the protection CPU, or error discovered during self-checking of the device, the “Abnormal” lamp should be on. In the event of TV fault, TA fault, 2nd harmonic blocking action, the “Alarm” lamp should be on. When the protection returns to normal, press the “Reset” button to rest all trip indication lamps.

8.2 Installation Precautions

a) The protection cabinet must be reliably earthed. Earthing copper terminal is provided inside the cabinet, which should be reliably connected to the earthing net of the power station.

b) When possible, use shielded cable, with the shielding layer earthed at the switch room and control room. The current wire of each phase and its neutral wire should be in the same cable.

c) Secondary loop of the current transformer is earthed only in the protection cabinet.

8.3 Device Information Meaning and Trouble-shooting

Table 1. Meaning of General Alarm Information

No. Information Meaning Trouble-shooting Remark1 Device failure Power supply failure

2 Device reset Check wiring between man-machine panel and

CPU, check whether CPU is updating the program. If can not be solved, inform the manufacturer.

3 Memory self-check error RAM chip is damaged Inform the manufacturer.

4 Setting self-check error Contents in setting area are damaged Inform the manufacturer.

5 Communication fault Check wiring between CPU and MMI, check

whether MMI is updating the program. If can not be solved, inform the manufacturer.

6 Control loop fault Circuit breaker position does not match with the status of the unit

7 TV fault The TV, TA loop is abnormal or sampling loop is abnormal

Check sampling value and secondary loop wiring; determine whether it is due to secondary loop reason

or hardware reason.

8 TA1 fault Ditto Ditto 9 TA2 fault Ditto Ditto 10 TA3 fault Ditto Ditto

Table 2. Meaning of Protection Alarm Information

No. Information Meaning Trouble-shooting Remark1 Id>Blk.by TA Fault Alarm element action Handle according to operation requirements 2 Id>Blk.by 2 Har Alarm element action Handle according to operation requirements 3 TA1 Saturation Alarm element action Handle according to operation requirements 4 TA2 Saturation Alarm element action Handle according to operation requirements 5 TA3 Saturation Alarm element action Handle according to operation requirements 6 O.L.Stage 1 Alarm Alarm element action Handle according to operation requirements 7 O.L.Stage 2 Alarm Alarm element action Handle according to operation requirements

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Table 3. Meaning of Protection Action Information

No. Information Meaning Trouble-shooting RemarkId>>trip by IA Protection element action Handle according to operation requirements 1 Id>>trip by IB Protection element action Handle according to operation requirements 2 Id>>trip by IC Protection element action Handle according to operation requirements 3 Id>trip by IA Protection element action Handle according to operation requirements 4 Id>trip by IB 5 Protection element action Handle according to operation requirements Id>trip by IC 6 Protection element action Handle according to operation requirements

Id>Pickup by IA 7 Protection element action Handle according to operation requirements Id>Pickup by IB 8 Protection element action Handle according to operation requirements Id>Pickup by IC 9 Protection element action Handle according to operation requirements

U</U2>Blk I>>trip 10 Protection element action Handle according to operation requirements 11 U</U2>Blk I>trip Protection element action Handle according to operation requirements 12 3Uo>>Trip Protection element action Handle according to operation requirements 13 3Uo>Trip Protection element action Handle according to operation requirements

8.4 Example of Fault Information

Complete protection action information includes the following contents: a) Fault report, which records the sequence record of the protection action process. Each record (fault

briefing) includes action information, action time and values of the related electric quantities. Following is an example of the record. During actual action, a complete fault report includes a number of records:

2006-10-18 11:47:12.307 Phase A differential pick-up occur Differential current and restraint current after pick-up Ida=0.49 Ie Idb=0.23 Ie Idc=0.26 Ie Ira=1.83 Ie Irb=0.73 Ie Irc=1.20 Ie b) Fault record wave form compatible with COMTRADE. The device can store maximum 6 times of fault

wave recording data, each wave recording uses continuous recording method, and each cycle records 16 points, maximum 4 seconds. The record wave form includes the whole process from the 2 cycles before proteciton pick-up, protection pick-up till trip, and it also includes the 40ms wave after the action returns.

Example of wave curve for each channel is shown in Figure 8-1.

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Trigger2006-10-18

15:28:41.567

t/s0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Ua/V

-100

0

t/s0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Ub/V

-100

-50

0

50

t/s0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Uc/V

-100

-50

0

50

t/s0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

3U0/V

-5.0

-2.5

0.0

2.5

t/s0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Ia1/A

-50

0

50

t/s0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Ib1/A

-50

0

50

t/s0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Ic1/A

-5.0

-2.5

0.0

2.5

t/s0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Ia2/A

-10

0

t/s0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Ib2/A

-10

0

t/s0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Ic2/A

-4

-2

0

2

t/s0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Ia3/A

-5

0

5

t/s0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Ib3/A

-5

0

t/s0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Ic3/A

-4

-2

0

2

t/s0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

TA2饱和TA3饱和

二次谐波闭锁差动B相比率差动动作A相比率差动动作B相差动速断动作A相差动速断动作

B相差动启动A相差动启动

Figure 8-1 Record wave form

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9 Storage

Packed devices should be stored by the manufacturer and user at a temperature between -25℃~70℃, maximum relative humidity 80%, and the ambient air should be free of acidic or alkali or other corrosive or explosive gases, and measures should be taken against ingress of moisture.

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10 Ordering Instructions

To order, please indicate: a) Product model number, name and ordered quantity. b) Rated AC current, voltage and frequency. c) Rated DC voltage. d) Communication method. e) Requirements for special functions and specially requested spare parts. f) Address and time for delivery.

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Annex

Annex 1 NSP712V3.0 Information Table and Submitted Measurement

1、 NSP712V3.0 submitted measurement, in order, includes: Ua, Ub, Uc, 3U0, U2, Uab, Ubc, Uca, F,

I1a, aI1ϕ ,I1b, bI1ϕ ,I1c, cI1ϕ ,I2a, aI 2ϕ ,I2b, bI 2ϕ ,I2c, cI 2ϕ ,I3a, aI 3ϕ ,I3b, bI 3ϕ ,I3c, cI 3ϕ ,Ida, Idb, Idc, Ira,

Irb, Irc. The values all have quality description bit, and are submitted according to the code value, in which , voltage 100V is corresponding to code value 1706, rated current value is corresponding to code value 1706, phase angel uses I1a as the zero degree reference angle, and 360 degree is corresponding to code value 2048, frequency 50Hz is corresponding to 1706, the differential current and restraint current are submitted using the actual values timed by 100.

2、 Information table: No. FUN INF Description(2 occur /1 cancel)

Device alarm information Prot.set Chk EM 1 194 222 Com.Abnormal 2 194 192

TV Fault 3 194 38 TA1 Fault 4 194 39 TA2 Fault 5 194 41

6 194 42 TA3 Fault 7 194 86 GPS Signal Lost 8 194 177 Fail Battery

Protection alarm information O.L.Stage 1 Alarm 1 194 150 O.L.Stage 2 Alarm 2 194 157 Id>Blk.by 2 Har 3 194 145

Id>Blk.by TA Fault 4 194 146 TA1 Saturation 5 194 147 TA2 Saturation 6 194 148 TA3 Saturation 7 194 149

Protection action information 1 194 61 Id>>trip by IA 2 194 63 Id>>trip by IB 3 194 64 Id>>trip by IC 4 194 62 Id>trip by IA 5 Id>trip by IB 194 65

Id>trip by IC 6 194 66 Id>Pickup by IA 7 194 67 Id>Pickup by IB 8 194 68 Id>Pickup by IC 9 194 69

10 194 70 U</U2>Blk I>>trip Side1 11 194 71 U</U2>Blk I>trip Side1 12 194 72 U</U2>Blk I>>trip Side2 13 194 73 U</U2>Blk I>trip Side2

3Uo>>Trip 14 194 109 3Uo>Trip 15 194 110

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Annex 2 NSP712V3.0 Transformer Differential Protection Device Setting Calculation

1 Transformer Differential Protection 1.1 Transformer Steady State Ratio Differential

(1) Current Reduction of Device NSP712 differential protection action is based on the secondary rated current of the protected object.

Normally, load current on each side of the transformer is value of the same percentage, at the rated load, the current of the HV and LV sides is “1”, or 100%. In this way, the analysis will be easy, no need to consider complicated calculations such as the vector fitting and TA transformation ratio. This is also a calculation method which is called “per unit value” in the analysis of electric system.

Based on the rated capacity, rated voltage and TA transformation ratio of the transformer, the PC protection automatically performs the conversion of current on each side. The formula for rated primary current on each side is:

n

nn U

SI

11 3=

Where：

nS is the rated capacity of the transformer, and

nU1 is the rated primary voltage on each side of the transformer.

The rated secondary current of the transformer is calculated from the rated primary current as follows:

LH

nn n

II 1

2 =

Where：

nI1 is the rated primary current on each side of the transformer, and

LHn is the TA transformation ratio on each side of the transformer.

(2) Vector Fitting in Per Unit Value Secondary of current transformer on each side of the transformer all uses Y connection, whose secondary

current is directly connected to the device. Through setting of the transformer capacity, rated voltage and TA transformation ratio on each side of the transformer and the connection method, the device automatically performs

phase adjustment for TA secondary current on each side of the transformer. The device uses Y change to

adjust the differential current balance. For example, for a Y/

>−Δ−Δ 11 connection, the calibration method is as

follows: For current on theΔside:

3/)(3/)(3/)( ***'***'***'bccabbcaa IIIIIIIII −=−=−= ；；

Where, *

aI , , are the per unit values of TA secondary current on theΔside, and *bI *

cI

aI *' , , are per unit value of current of each phase after connection on theΔside. bI *'cI *'

(3) Setting of Differential Current Pick-up Value >dI

>dI is the minimum action current value for differential protection, which should be set according to the

maximum unbalanced current evading the normal rated capacity of the transformer, which is:

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nerreld ImUKKI 2)( Δ+Δ+>=

Where,

nI 2 is the rated secondary current of the transformer;

relK is the reliability coefficient, which normally takes 1.3~1.5;

erK is the ratio error of the current transformer (take 0.03×2 for 10P type, and 0.01×2 for 5P type);

UΔ is the error caused by voltage adjustment of the transformer, and mΔ is the error caused by incomplete matching of transformation ratio of the current transformer, which

can take 0.05.

In actual engineering setting calculation, can take (0.2~0.5) , and should actually measure the

unbalanced current in the loop at the maximum load.

>dI nI 2

For excitation transformer, as the forced excitation duration during work is long, and the difference between TA characteristics on both sides is big, and the unbalanced value of differential current is big, so, it is

recommended that the differential pick-up value should be larger than 0.5 . nI 2

(4) Setting of Knee Current According to above analysis and the working principle of differential protection, the first knee current

is normally set around the transformer’s rated current , which means is around “1”. The

second knee current is normally set at 2~6 times of the rated current, which means is between 2~6,

this should be determined according to the TA saturation point in actual engineering.

nIKb1 nI 1Kb

nIKb2 2Kb

(5) Setting of Ratio Restraint Factor Ratio differential pick-up current strating slope:

relapercc KmUKKKK ×Δ+Δ+××= )(1

Where,

ccK is the transformer common mode factor, take 1.0;

erK is the transformer ratio error factor, for setting calculation take 0.1;

apK is the periodical component factor, take 2;

relK is the reliability coefficient, take 1.3~1.5;

mU ΔΔ , is same as above; and

1K normally takes 0.10~0.30.

Ratio differential pick-up current maximum strating slope is:

212max.

121max.12

)(rel

K

dunbrel KKbKbI

KbKbKIIKK ×−−

−×−>−×= ∗

∗

For two-winding transformer:

max.max. )( kccerapunb ImUKKKI ×Δ+Δ+=

For three-winding transformer (take the example of external short-circuit on LV side):

max..max..max..max..max.max. IIkIIIkImkmhkhkerccapunb ImImIUIUIKKKI Δ+Δ+Δ+Δ+=

Where：

max.unbI is the maximum unbalanced current;

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apK is the periodical component factor, for current transformer of TP grade on both sides, take 1.0, for

current transformer of P grade on both sides, take 1.5~2.0 (for all use of 5P or 10P type, TA take 2.0, do not use TPY and 5P or 10P type TA to form the longitudinal difference protection of transformer);

erK , , are same as above; UΔ mΔ

hUΔ , are relative error (relative to Un) caused by the voltage adjustment on the HV and MV side of the transformer, take the maximum value (percent) away from the rated value in the voltage adjustment range;

mUΔ

III mm ΔΔ , are the respective errors caused by incomplete matching of transformation ratio of the current transformer (including the intermediate converter);

max..max.. , mkhk II are the respective periodical components (secondary value) of the current flowing through the current transformer on the voltage adjustment side during calculation of external short-circuit on LV side;

max..max.. , IIkIk II are the respective periodical components (secondary value) of the current flowing through the current transformer on both sides not close to the fault point during calculation of external short-circuit on LV side;

max.kI is the secondary value of the transformer’s maximum external three-phase short-circuit current, if it is less than 4 times of rated current, take 4 times of rated current,;

∗max.unbI , , are per unit values (based on the rated current of the transformer); >dI ∗

max.KI

1relK is the reliability coefficient, take 1.3~1.5;

2relK is the reliability coefficient considering TA saturation, take 2.0~3.0, and

2K is recommended to take 0.50. For the ratio restraint characteristics set according to the above principles, in the event of metallic

short-circuit in two phases of the transformer’s generator terminal, the differential protection sensitivity

coefficient should satisfy . 2≥senK

(6) Setting of Harmonic Restraint Factor In the differential protection using 2nd harmonic to avoid accidental operation of excitation surge current, the

2nd harmonic restraint ratio means the ratio between the 2nd harmonic component and the first harmonic component of the differential current. Normally, 2nd harmonic restraint ratio can be set to 15%~20%。

1.2 Differential Instantaneous Trip Protection Differential current instantaneous trip is a supplementary part of ratio differential protection, normally based

on the maximum charging current when evading the idle transformer. Normally take 6~8 times of the rated current.

2 Under Voltage or Over negative Sequence Voltage Block and Over Current Protection (1) Setting calculation of current relay Action current of the current relay should be set according to the evading of the transformer’s rated current,

and the formula is as follows:

nr

relset I

KK

I 2=

Where：

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relK is the reliability coefficient, take 1.3~1.5;

rK is the return coefficient, take 0.85~0.95;

nI 2 is the secondary value of the transformer’s rated current. Sensitivity factor of the current relay should be verified as follows:

set

ksen I

IK

)2(min.=

Where： )2(

min.kI is the minimum short-circuit current (secondary value) flowing through the protection in the event of

metallic short-circuit in two phases of the HV side busbar of the main transformer, requirement . 2.1≥senK

(2) LV element take the line voltage, tripping voltage can be set according to the following formula. setUl

nset UUl 6.0=

Where：

nU is the secondary value of the transformer’s rated voltage. Sensitivity factor should be verified based on the short-circuit of three phases in the busbar on the HV side of

the transformer:

)3(max.kt

setsen IX

UlK

×=

Where： )3(max.kI is the maximum short-circuit current (secondary value) in the event of metallic short-circuit of three

phases in the busbar on the HV side of the transformer;

tX tt ZX = is the reactance of the main transformer, take .

Requirement . 2.1≥senK

(3) Setting calculation for negative sequence voltage relay Negative sequence voltage relay should be set according to the evading of unbalanced voltage occurred

during normal operation, normally take:

nset UU )08.006.0(.2 −=

Where：

nU is the secondary value of the rated voltage. Sensitivity factor should be verified based on the short-circuit of two phases in the busbar on the HV side of

the transformer:

setsen U

UK

.2

min.2=

Where：

min.2U is the minimum negative sequence voltage at the installed location of the protection in the event of

short-circuit of two phases in the busbar on the HV side of the transformer.

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Requirement . 5.1≥senK

Annex 3 Terminal Layout

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Annex 4 Terminal Wiring Diagram

1 NSP712 Terminal Wiring Diagram

-40-


2 NSP712A Terminal Wiring Diagram

-41-


Annex 5 Opening Dimensions

244

6

Outline dimension sketch Installation opening dimension sketch

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Annex 6 Ordering Number

NSP712(V3.0) 1

Communication methodR: Single RS 485 network, twisted pairD: double RS 485 network, twisted pairS: single EtherNet, CAT 5E: double EtherNet, CAT 5T: triple EtherNet, CAT 5

Tele-pulse/clock synchronization method selectionG: GPS 1PPM or IRIG-B input (24V)B: Differential input IRIG-B

Specification of zero sequence TV in three-side differential1: rated value of zero sequence TV Un=100V

Specification of protection TA1: same rated values on each side, In=1A2: I side In= 1A, II side In= 1A, III side In= 5A3: I side In= 1A, II side In= 5A, III side In= 1A4: I side In= 1A, II side In= 5A, III side In= 5A5: same rated values on each side, In=5A

Power supply voltage1: DC110V, 14 DC110V binary input2: DC220V, 14 DC220V binary input

Description of NSP712(V3.0)Series Device Model Number

0

Production information

Additional informationNone:transformer three-side differentialA: transformer four-side differential

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NSP712 Diff.protection English Version

Documents

respective periodical components

german protection

binary input status

ta transformation ratio

clock synchronization mode

earthing 11 oclock wiring

earthing 1 oclock wiring

operation requirements handle