### Overview

In the “Line differential protection, 3 or 6 CT sets” function, the L3CPDIF is used for conventional two-terminal lines with or without a 1½ circuit breaker arrangement in one end, as well as three-terminal lines with single breaker arrangements at all terminals. The L6CPDIF is used for conventional two-terminal lines with 1½ circuit breaker arrangements in

both ends, as well as multi-terminal lines with up to five terminals.

For more detailed information on “Line differential protection 3 or 6 CT sets, with in-zone transformers”, refer to ABB, Relion 670 Series manuals.

To see other supported functions, click here.

#### Function Identification

Function description | IEC 61850 identification |
IEC 60617 identification |
ANSI/IEEE C37.2 device number |

Line differential protection, 3 CT sets, 2-3 line ends | L3CPDIF | 3Id/I > | 87L |

Line differential protection, 6 CT sets, 3-5 line ends | L6CPDIF | 3Id/I > | 87L |

Line differential protection 3 CT sets, with in-zone transformers, 2-3 line ends | LT3CPDIF | 3Id/I > | 87T |

Line differential protection 6 CT sets, with in-zone transformers, 3-5 line ends | LT6CPDIF | 3Id/I > | 87T |

Line differential logic | LDLPSCH | 3Id/I > | 87L |

### Signals & Setting Parameters

#### L3CPDIF function block

#### L3CPDIF Input signals

L3CPDIF Input signals | |||

Name | Type | Default | Description |

I3P1 | GROUP SIGNAL | – | Three phase current grp1 samples and DFT values |

I3P2 | GROUP SIGNAL | – | Three phase current grp2 samples and DFT values |

I3P3 | GROUP SIGNAL | – | Three phase current grp3 samples and DFT values |

#### L3CPDIF Output signals

L3CPDIF Output signals | |||

Name | Type | Description | |

TRIP | BOOLEAN | Common, main, trip output signal | |

TRL1 | BOOLEAN | Trip signal from phase L1 | |

TRL2 | BOOLEAN | Trip signal from phase L2 | |

TRL3 | BOOLEAN | Trip signal from phase L3 | |

STARTRES | BOOLEAN | Start of restrained differential protection | |

STARTUNR | BOOLEAN | Start of unrestrained differential protection | |

STARTENH | BOOLEAN | Start of enhanced restrained differential protection | |

START | BOOLEAN | Common, main, start output signal | |

STL1 | BOOLEAN | Start signal from phase L1 | |

STL2 | BOOLEAN | Start signal from phase L2 | |

STL3 | BOOLEAN | Start signal from phase L3 | |

INTFAULT | BOOLEAN | Internal fault has been detected | |

EXTFAULT | BOOLEAN | External fault has been detected | |

BLK2H | BOOLEAN | Common block signal, due to 2nd harmonic | |

BLK2HL1 | BOOLEAN | Block signal due to 2nd harmonic, phase L1 | |

BLK2HL2 | BOOLEAN | Block signal due to 2nd harmonic, phase L2 | |

BLK2HL3 | BOOLEAN | Block signal due to 2nd harmonic, phase L3 | |

BLK5H | BOOLEAN | Common block signal, due to 5-th harmonic | |

BLK5HL1 | BOOLEAN | Block signal due to 5th harmonic, phase L1 | |

BLK5HL2 | BOOLEAN | Block signal due to 5th harmonic, phase L2 | |

BLK5HL3 | BOOLEAN | Block signal due to 5th harmonic, phase L3 | |

ALARM | BOOLEAN | Alarm for sustained differential current | |

OPENCT | BOOLEAN | An open CT was detected | |

OPENCTAL | BOOLEAN | Open CT Alarm output signal. Issued after a delay … | |

IDL1 | REAL | Instantaneous differential current, phase L1 | |

IDL2 | REAL | Instantaneous differential current, phase L2 | |

IDL3 | REAL | Instantaneous differential current, phase L3 | |

IDL1MAG | REAL | Magnitude of fund. freq. differential current, phase L1 | |

IDL2MAG | REAL | Magnitude of fund. freq. differential current, phase L2 | |

IDL3MAG | REAL | Magnitude of fund. freq. differential current, phase L3 | |

IBIAS | REAL | Magnitude of the bias current, common for L1, L2, L3 | |

IDNSMAG | REAL | Magnitude of the negative sequence differential current | |

#### L3CPDIF Group settings (basic)

L3CPDIF Group settings (basic) | |||||

Name | Values (Range) | Unit | Step | Default | Description |

Operation | Off On |
– | – | Off | Operation Off / On |

IdMin | 0.20 – 2.00 | IB | 0.01 | 0.30 | Oper – restr charact., section 1 sensitivity, multiple IBase |

IdMinHigh | 0.20 – 10.00 | IB | 0.01 | 0.80 | Initial lower sensitivity, as multiple of IBase |

tIdMinHigh | 0.000 – 60.000 | s | 0.001 | 1.000 | Time interval of initial lower sensitivity, in sec |

IdUnre | 1.00 – 50.00 | IB | 0.01 | 10.00 | Unrestrained differential current limit, multiple of IBase |

NegSeqDiffEn | Off On |
– | – | On | Off/On selection for internal / external fault discriminator |

NegSeqROA | 30.0 – 120.0 | Deg | 1.0 | 60.0 | Internal/external fault discriminator Operate Angle, degrees |

IMinNegSeq | 0.01 – 0.20 | IB | 0.01 | 0.04 | Min. value of neg. seq. curr. as multiple of IBase |

CrossBlockEn | No Yes |
– | – | No | Off/On selection of the cross -block logic |

ChargCurEnable | Off On |
– | – | Off | Off/On selection for compensation of charging currents |

AddDelay | Off On |
– | – | Off | Off/On selection for delayed diff. trip command |

IMaxAddDelay | 0.20 – 5.00 | IB | 0.01 | 1.00 | Below limit, extra delay can be applied, multiple of IBase |

tDefTime | 0.000 – 6.000 | s | 0.001 | 0.000 | Definite time additional delay in seconds |

tMinInv | 0.001 – 6.000 | s | 0.001 | 0.010 | Inverse Delay Minimum Time. In seconds |

CurveType | ANSI Ext. inv. ANSI Very inv. ANSI Norm. inv. ANSI Mod. inv. ANSI Def. Time L.T.E. inv. L.T.V. inv. L.T. inv. IEC Norm. inv. IEC Very inv. IEC inv. IEC Ext. inv. IEC S.T. inv. IEC L.T. inv. IEC Def. Time Programmable RI type RD type |
– | – | IEC Def. Time | 19 curve types. Example: 15 for definite time delay. |

k | 0.05 – 1.10 | – | 0.01 | 1.00 | Time Multiplier Setting (TMS) for inverse delays |

IdiffAlarm | 0.05 – 1.00 | IB | 0.01 | 0.15 | Sustained differential current alarm, factor of IBase |

tAlarmdelay | 0.000 – 60.000 | s | 0.001 | 10.000 | Delay for alarm due to sustained differential current, in s |

#### L3CPDIF Group settings (advanced)

L3CPDIF Group settings (advanced) | |||||

Name | Values (Range) | Unit | Step | Default | Description |

EndSection1 | 0.20 – 1.50 | IB | 0.01 | 1.25 | End of section 1, as multiple of reference current IBase |

EndSection2 | 1.00 – 10.00 | IB | 0.01 | 3.00 | End of section 2, as multiple of reference current IBase |

SlopeSection2 | 10.0 – 50.0 | % | 0.1 | 40.0 | Slope in section 2 of operate-restrain characteristic, in % |

SlopeSection3 | 30.0 – 100.0 | % | 0.1 | 80.0 | Slope in section 3 of operate- restrain characteristic, in % |

I2/I1Ratio | 5.0 – 100.0 | % | 1.0 | 10.0 | Max. ratio of 2nd harm. to fundamental harm dif. curr. in % |

I5/I1Ratio | 5.0 – 100.0 | % | 1.0 | 25.0 | Max. ratio of 5th harm. to fundamental harm dif. curr. in % |

p | 0.01 – 1000.00 | – | 0.01 | 0.02 | Settable curve parameter, user- programmable curve type. |

a | 0.01 – 1000.00 | – | 0.01 | 0.14 | Settable curve parameter, user- programmable curve type. |

b | 0.01 – 1000.00 | – | 0.01 | 1.00 | Settable curve parameter, user- programmable curve type. |

c | 0.01 – 1000.00 | – | 0.01 | 1.00 | Settable curve parameter, user- programmable curve type. |

OpenCTEnable | Off On |
– | – | On | Open CTEnable Off/On |

tOCTAlarmDelay | 0.100 – 10.000 | s | 0.001 | 1.000 | Open CT: time in s to alarm after an open CT is detected |

tOCTResetDelay | 0.100 – 10.000 | s | 0.001 | 0.250 | Reset delay in s. After delay, diff. function is activated |

OCTBlockEn | Off On |
– | – | On | Enable Open CT blocking function trip Off/On |

#### L3CPDIF Non group settings (basic)

L3CPDIF Non group settings (basic) | |||||

Name | Values (Range) | Unit | Step | Default | Description |

GlobalBaseSel | 1 – 12 | – | 1 | 1 | Selection of one of the Global Base Value groups |

NoOfUsedCTs | 2 3 |
– | – | 2 | Total number of 3-Ph CT sets connected to diff protection |

#### L3CPDIF Monitored data

L3CPDIF Monitored data | ||||

Name | Type | Values (Range) | Unit | Description |

IDL1MAG | REAL | – | A | Magnitude of fund. freq. differential current, phase L1 |

IDL2MAG | REAL | – | A | Magnitude of fund. freq. differential current, phase L2 |

IDL3MAG | REAL | – | A | Magnitude of fund. freq. differential current, phase L3 |

IBIAS | REAL | – | A | Magnitude of the bias current, common for L1, L2, L3 |

IDNSMAG | REAL | – | A | Magnitude of the negative sequence differential current |

NSANGLE | REAL | – | deg | Angle between local and remote neg. seq. currents |

ICHARGE | REAL | – | A | Amount of compensated charging current |

#### L6CPDIF function block

#### L6CPDIF Input signals

L6CPDIF Input signals | |||

Name | Type | Default | Description |

I3P1 | GROUP SIGNAL | – | Three phase current grp1 samples and DFT values |

I3P2 | GROUP SIGNAL | – | Three phase current grp2 samples and DFT values |

I3P3 | GROUP SIGNAL | – | Three phase current grp3 samples and DFT values |

I3P4 | GROUP SIGNAL | – | Three phase current grp4 samples and DFT values |

I3P5 | GROUP SIGNAL | – | Three phase current grp5 samples and DFT values |

I3P6 | GROUP SIGNAL | – | Three phase current grp6 samples and DFT values |

#### L6CPDIF Output signals

L6CPDIF Output signals | |||

Name | Type | Description | |

TRIP | BOOLEAN | Common, main, trip output signal | |

TRL1 | BOOLEAN | Trip signal from phase L1 | |

TRL2 | BOOLEAN | Trip signal from phase L2 | |

TRL3 | BOOLEAN | Trip signal from phase L3 | |

STARTRES | BOOLEAN | Start of restrained differential protection | |

STARTUNR | BOOLEAN | Start of unrestrained differential protection | |

STARTENH | BOOLEAN | Start of enhanced restrained differential protection | |

START | BOOLEAN | Common, main, start output signal | |

STL1 | BOOLEAN | Start signal from phase L1 | |

STL2 | BOOLEAN | Start signal from phase L2 | |

STL3 | BOOLEAN | Start signal from phase L3 | |

INTFAULT | BOOLEAN | Internal fault has been detected | |

EXTFAULT | BOOLEAN | External fault has been detected | |

BLK2H | BOOLEAN | Common block signal, due to 2nd harmonic | |

BLK2HL1 | BOOLEAN | Block signal due to 2nd harmonic, phase L1 | |

BLK2HL2 | BOOLEAN | Block signal due to 2nd harmonic, phase L2 | |

BLK2HL3 | BOOLEAN | Block signal due to 2nd harmonic, phase L3 | |

BLK5H | BOOLEAN | Common block signal, due to 5-th harmonic | |

BLK5HL1 | BOOLEAN | Block signal due to 5th harmonic, phase L1 | |

BLK5HL2 | BOOLEAN | Block signal due to 5th harmonic, phase L2 | |

BLK5HL3 | BOOLEAN | Block signal due to 5th harmonic, phase L3 | |

ALARM | BOOLEAN | Alarm for sustained differential current | |

OPENCT | BOOLEAN | An open CT was detected | |

OPENCTAL | BOOLEAN | Open CT Alarm output signal. Issued after a delay … | |

IDL1 | REAL | Instantaneous differential current, phase L1 | |

IDL2 | REAL | Instantaneous differential current, phase L2 | |

IDL3 | REAL | Instantaneous differential current, phase L3 | |

IDL1MAG | REAL | Magnitude of fund. freq. differential current, phase L1 | |

IDL2MAG | REAL | Magnitude of fund. freq. differential current, phase L2 | |

IDL3MAG | REAL | Magnitude of fund. freq. differential current, phase L3 | |

IBIAS | REAL | Magnitude of the bias current, common for L1, L2, L3 | |

IDNSMAG | REAL | Magnitude of the negative sequence differential current | |

#### L6CPDIF Group settings (basic)

L6CPDIF Group settings (basic) | |||||

Name | Values (Range) | Unit | Step | Default | Description |

Operation | Off On |
– | – | Off | Operation Off / On |

IdMin | 0.20 – 2.00 | IB | 0.01 | 0.30 | Oper – restr charact., section 1 sensitivity, multiple IBase |

IdMinHigh | 0.20 – 10.00 | IB | 0.01 | 0.80 | Initial lower sensitivity, as multiple of IBase |

tIdMinHigh | 0.000 – 60.000 | s | 0.001 | 1.000 | Time interval of initial lower sensitivity, in sec |

IdUnre | 1.00 – 50.00 | IB | 0.01 | 10.00 | Unrestrained differential current limit, multiple of IBase |

NegSeqDiffEn | Off On |
– | – | On | Off/On selection for internal / external fault discriminator |

NegSeqROA | 30.0 – 120.0 | Deg | 1.0 | 60.0 | Internal/external fault discriminator Operate Angle, degrees |

IMinNegSeq | 0.01 – 0.20 | IB | 0.01 | 0.04 | Min. value of neg. seq. curr. as multiple of IBase |

CrossBlockEn | No Yes |
– | – | No | Off/On selection of the cross -block logic |

I2/I1Ratio | 5.0 – 100.0 | % | 1.0 | 10.0 | Max. ratio of 2nd harm. to fundamental harm dif. curr. in % |

I5/I1Ratio | 5.0 – 100.0 | % | 1.0 | 25.0 | Max. ratio of 5th harm. to fundamental harm dif. curr. in % |

ChargCurEnable | Off On |
– | – | Off | Off/On selection for compensation of charging currents |

AddDelay | Off On |
– | – | Off | Off/On selection for delayed diff. trip command |

IMaxAddDelay | 0.20 – 5.00 | IB | 0.01 | 1.00 | Below limit, extra delay can be applied, multiple of IBase |

tDefTime | 0.000 – 6.000 | s | 0.001 | 0.000 | Definite time additional delay in seconds |

tMinInv | 0.001 – 6.000 | s | 0.001 | 0.010 | Inverse Delay Minimum Time. In seconds |

CurveType | ANSI Ext. inv. ANSI Very inv. ANSI Norm. inv. ANSI Mod. inv. ANSI Def. Time L.T.E. inv. L.T.V. inv. L.T. inv. IEC Norm. inv. IEC Very inv. IEC inv. IEC Ext. inv. IEC S.T. inv. IEC L.T. inv. IEC Def. Time Programmable RI type RD type |
– | – | IEC Def. Time | 19 curve types. Example: 15 for definite time delay. |

k | 0.05 – 1.10 | – | 0.01 | 1.00 | Time Multiplier Setting (TMS) for inverse delays |

IdiffAlarm | 0.05 – 1.00 | IB | 0.01 | 0.15 | Sustained differential current alarm, factor of IBase |

tAlarmdelay | 0.000 – 60.000 | s | 0.001 | 10.000 | Delay for alarm due to sustained differential current, in s |

#### L6CPDIF Group settings (advanced)

L6CPDIF Group settings (advanced) | |||||

Name | Values (Range) | Unit | Step | Default | Description |

EndSection1 | 0.20 – 1.50 | IB | 0.01 | 1.25 | End of section 1, as multiple of reference current IBase |

EndSection2 | 1.00 – 10.00 | IB | 0.01 | 3.00 | End of section 2, as multiple of reference current IBase |

SlopeSection2 | 10.0 – 50.0 | % | 0.1 | 40.0 | Slope in section 2 of operate-restrain characteristic, in % |

SlopeSection3 | 30.0 – 100.0 | % | 0.1 | 80.0 | Slope in section 3 of operate- restrain characteristic, in % |

p | 0.01 – 1000.00 | – | 0.01 | 0.02 | Settable curve parameter, user- programmable curve type. |

a | 0.01 – 1000.00 | – | 0.01 | 0.14 | Settable curve parameter, user- programmable curve type. |

b | 0.01 – 1000.00 | – | 0.01 | 1.00 | Settable curve parameter, user- programmable curve type. |

c | 0.01 – 1000.00 | – | 0.01 | 1.00 | Settable curve parameter, user- programmable curve type. |

OpenCTEnable | Off On |
– | – | On | Open CTEnable Off/On |

tOCTAlarmDelay | 0.100 – 10.000 | s | 0.001 | 1.000 | Open CT: time in s to alarm after an open CT is detected |

tOCTResetDelay | 0.100 – 10.000 | s | 0.001 | 0.250 | Reset delay in s. After delay, diff. function is activated |

OCTBlockEn | Off On |
– | – | On | Enable Open CT blocking function trip Off/On |

#### L6CPDIF Non group settings (basic)

L6CPDIF Non group settings (basic) | |||||

Name | Values (Range) | Unit | Step | Default | Description |

GlobalBaseSel | 1 – 12 | – | 1 | 1 | Selection of one of the Global Base Value groups |

NoOfUsedCTs | 2 3 4 5 6 |
– | – | 2 | Total number of 3-Ph CT sets connected to diff protection |

#### L6CPDIF Monitored data

L6CPDIF Monitored data | ||||

Name | Type | Values (Range) | Unit | Description |

IDL1MAG | REAL | – | A | Magnitude of fund. freq. differential current, phase L1 |

IDL2MAG | REAL | – | A | Magnitude of fund. freq. differential current, phase L2 |

IDL3MAG | REAL | – | A | Magnitude of fund. freq. differential current, phase L3 |

IBIAS | REAL | – | A | Magnitude of the bias current, common for L1, L2, L3 |

IDNSMAG | REAL | – | A | Magnitude of the negative sequence differential current |

NSANGLE | REAL | – | deg | Angle between local and remote neg. seq. currents |

ICHARGE | REAL | – | A | Amount of compensated charging current |

#### LT3CPDIF function block

#### LT3CPDIF Input signals

LT3CPDIF Input signals | |||

Name | Type | Default | Description |

I3P1 | GROUP SIGNAL | – | Three phase current grp1 samples and DFT values |

I3P2 | GROUP SIGNAL | – | Three phase current grp2 samples and DFT values |

I3P3 | GROUP SIGNAL | – | Three phase current grp3 samples and DFT values |

#### LT3CPDIF Output signals

LT3CPDIF Output signals | |||

Name | Type | Description | |

TRIP | BOOLEAN | Common, main, trip output signal | |

TRL1 | BOOLEAN | Trip signal from phase L1 | |

TRL2 | BOOLEAN | Trip signal from phase L2 | |

TRL3 | BOOLEAN | Trip signal from phase L3 | |

STARTRES | BOOLEAN | Start of restrained differential protection | |

STARTUNR | BOOLEAN | Start of unrestrained differential protection | |

STARTENH | BOOLEAN | Start of enhanced restrained differential protection | |

START | BOOLEAN | Common, main, start output signal | |

STL1 | BOOLEAN | Start signal from phase L1 | |

STL2 | BOOLEAN | Start signal from phase L2 | |

STL3 | BOOLEAN | Start signal from phase L3 | |

INTFAULT | BOOLEAN | Internal fault has been detected | |

EXTFAULT | BOOLEAN | External fault has been detected | |

BLK2H | BOOLEAN | Common block signal, due to 2nd harmonic | |

BLK2HL1 | BOOLEAN | Block signal due to 2nd harmonic, phase L1 | |

BLK2HL2 | BOOLEAN | Block signal due to 2nd harmonic, phase L2 | |

BLK2HL3 | BOOLEAN | Block signal due to 2nd harmonic, phase L3 | |

BLK5H | BOOLEAN | Common block signal, due to 5-th harmonic | |

BLK5HL1 | BOOLEAN | Block signal due to 5th harmonic, phase L1 | |

BLK5HL2 | BOOLEAN | Block signal due to 5th harmonic, phase L2 | |

BLK5HL3 | BOOLEAN | Block signal due to 5th harmonic, phase L3 | |

ALARM | BOOLEAN | Alarm for sustained differential current | |

OPENCT | BOOLEAN | An open CT was detected | |

OPENCTAL | BOOLEAN | Open CT Alarm output signal. Issued after a delay … | |

IDL1 | REAL | Instantaneous differential current, phase L1 | |

IDL2 | REAL | Instantaneous differential current, phase L2 | |

IDL3 | REAL | Instantaneous differential current, phase L3 | |

IDL1MAG | REAL | Magnitude of fund. freq. differential current, phase L1 | |

IDL2MAG | REAL | Magnitude of fund. freq. differential current, phase L2 | |

IDL3MAG | REAL | Magnitude of fund. freq. differential current, phase L3 | |

IBIAS | REAL | Magnitude of the bias current, common for L1, L2, L3 | |

IDNSMAG | REAL | Magnitude of the negative sequence differential current | |

#### LT3CPDIF Group settings (basic)

LT3CPDIF Group settings (basic) | |||||

Name | Values (Range) | Unit | Step | Default | Description |

Operation | Off On |
– | – | Off | Operation Off / On |

IdMin | 0.20 – 2.00 | IB | 0.01 | 0.30 | Oper – restr charact., section 1 sensitivity, multiple IBase |

IdMinHigh | 0.20 – 10.00 | IB | 0.01 | 0.80 | Initial lower sensitivity, as multiple of IBase |

tIdMinHigh | 0.000 – 60.000 | s | 0.001 | 1.000 | Time interval of initial lower sensitivity, in sec |

IdUnre | 1.00 – 50.00 | IB | 0.01 | 10.00 | Unrestrained differential current limit, multiple of IBase |

NegSeqDiffEn | Off On |
– | – | On | Off/On selection for internal / external fault discriminator |

NegSeqROA | 30.0 – 120.0 | Deg | 1.0 | 60.0 | Internal/external fault discriminator Operate Angle, degrees |

IMinNegSeq | 0.01 – 0.20 | IB | 0.01 | 0.04 | Min. value of neg. seq. curr. as multiple of IBase |

CrossBlockEn | No Yes |
– | – | No | Off/On selection of the cross -block logic |

ChargCurEnable | Off On |
– | – | Off | Off/On selection for compensation of charging currents |

AddDelay | Off On |
– | – | Off | Off/On selection for delayed diff. trip command |

IMaxAddDelay | 0.20 – 5.00 | IB | 0.01 | 1.00 | Below limit, extra delay can be applied, multiple of IBase |

tDefTime | 0.000 – 6.000 | s | 0.001 | 0.000 | Definite time additional delay in seconds |

tMinInv | 0.001 – 6.000 | s | 0.001 | 0.010 | Inverse Delay Minimum Time. In seconds |

CurveType | ANSI Ext. inv. ANSI Very inv. ANSI Norm. inv. ANSI Mod. inv. ANSI Def. Time L.T.E. inv. L.T.V. inv. L.T. inv. IEC Norm. inv. IEC Very inv. IEC inv. IEC Ext. inv. IEC S.T. inv. IEC L.T. inv. IEC Def. Time Programmable RI type RD type |
– | – | IEC Def. Time | 19 curve types. Example: 15 for definite time delay. |

k | 0.05 – 1.10 | – | 0.01 | 1.00 | Time Multiplier Setting (TMS) for inverse delays |

IdiffAlarm | 0.05 – 1.00 | IB | 0.01 | 0.15 | Sustained differential current alarm, factor of IBase |

tAlarmdelay | 0.000 – 60.000 | s | 0.001 | 10.000 | Delay for alarm due to sustained differential current, in s |

#### LT3CPDIF Group settings (advanced)

LT3CPDIF Group settings (advanced) | |||||

Name | Values (Range) | Unit | Step | Default | Description |

EndSection1 | 0.20 – 1.50 | IB | 0.01 | 1.25 | End of section 1, as multiple of reference current IBase |

EndSection2 | 1.00 – 10.00 | IB | 0.01 | 3.00 | End of section 2, as multiple of reference current IBase |

SlopeSection2 | 10.0 – 50.0 | % | 0.1 | 40.0 | Slope in section 2 of operate-restrain characteristic, in % |

SlopeSection3 | 30.0 – 100.0 | % | 0.1 | 80.0 | Slope in section 3 of operate- restrain characteristic, in % |

I2/I1Ratio | 5.0 – 100.0 | % | 1.0 | 10.0 | Max. ratio of 2nd harm. to fundamental harm dif. curr. in % |

I5/I1Ratio | 5.0 – 100.0 | % | 1.0 | 25.0 | Max. ratio of 5th harm. to fundamental harm dif. curr. in % |

p | 0.01 – 1000.00 | – | 0.01 | 0.02 | Settable curve parameter, user- programmable curve type. |

a | 0.01 – 1000.00 | – | 0.01 | 0.14 | Settable curve parameter, user- programmable curve type. |

b | 0.01 – 1000.00 | – | 0.01 | 1.00 | Settable curve parameter, user- programmable curve type. |

c | 0.01 – 1000.00 | – | 0.01 | 1.00 | Settable curve parameter, user- programmable curve type. |

OpenCTEnable | Off On |
– | – | On | Open CTEnable Off/On |

tOCTAlarmDelay | 0.100 – 10.000 | s | 0.001 | 1.000 | Open CT: time in s to alarm after an open CT is detected |

tOCTResetDelay | 0.100 – 10.000 | s | 0.001 | 0.250 | Reset delay in s. After delay, diff. function is activated |

OCTBlockEn | Off On |
– | – | On | Enable Open CT blocking function trip Off/On |

#### LT3CPDIF Non group settings (basic)

LT3CPDIF Non group settings (basic) | |||||

Name | Values (Range) | Unit | Step | Default | Description |

GlobalBaseSel | 1 – 12 | – | 1 | 1 | Selection of one of the Global Base Value groups |

NoOfUsedCTs | 2 3 |
– | – | 2 | Total number of 3-Ph CT sets connected to diff protection |

ZerSeqCurSubtr | Off On |
– | – | Off | Off/On for elimination of zero seq. from diff. and bias curr |

TraAOnInpCh | No Transf A 1 2 3 |
– | – | No Transf A | Power transformer A applied on input channel X |

RatVoltW1TraA | 1.0 – 9999.9 | kV | 0.1 | 130.0 | Transformer A rated voltage (kV) on winding 1 (HV winding) |

RatVoltW2TraA | 1.0 – 9999.9 | kV | 0.1 | 130.0 | Transformer A rated voltage (kV) on winding 2 (LV winding) |

ClockNumTransA | 0 [0 deg] 1 [30 deg lag] 2 [60 deg lag] 3 [90 deg lag] 4 [120 deg lag] 5 [150 deg lag] 6 [180 deg lag] 7 [210 deg lag] 8 [240 deg lag] 9 [270 deg lag] 10 [300 deg lag] 11 [330 deg lag] |
– | – | 0 [0 deg] | Transf. A phase shift in multiples of 30 deg, 5 for 150 deg |

TraBOnInpCh | No Transf B 1 2 3 |
– | – | No Transf B | Power transformer B applied on input channel X |

RatVoltW1TraB | 1.0 – 9999.9 | kV | 0.1 | 130.0 | Transformer B rated voltage (kV) on winding 1 (HV winding) |

RatVoltW2TraB | 1.0 – 9999.9 | kV | 0.1 | 130.0 | Transformer B rated voltage (kV) on winding 2 (LV winding) |

ClockNumTransB | 0 [0 deg] 1 [30 deg lag] 2 [60 deg lag] 3 [90 deg lag] 4 [120 deg lag] 5 [150 deg lag] 6 [180 deg lag] 7 [210 deg lag] 8 [240 deg lag] 9 [270 deg lag] 10 [300 deg lag] 11 [330 deg lag] |
– | – | 0 [0 deg] | Transf. B phase shift in multiples of 30 deg, 2 for 60 deg |

#### LT3CPDIF Monitored data

LT3CPDIF Monitored data | ||||

Name | Type | Values (Range) | Unit | Description |

OPENCTIN | INTEGER | – | – | Open CT on Input : 1 for input 1, 2 for input 2 |

OPENCTPH | INTEGER | – | – | Open CT in Phase : 1 for L1, 2 for L2, 3 for L3 |

IDL1MAG | REAL | – | A | Magnitude of fund. freq. differential current, phase L1 |

IDL2MAG | REAL | – | A | Magnitude of fund. freq. differential current, phase L2 |

IDL3MAG | REAL | – | A | Magnitude of fund. freq. differential current, phase L3 |

IBIAS | REAL | – | A | Magnitude of the bias current, common for L1, L2, L3 |

IDNSMAG | REAL | – | A | Magnitude of the negative sequence differential current |

NSANGLE | REAL | – | deg | Angle between local and remote neg. seq. currents |

ICHARGE | REAL | – | A | Amount of compensated charging current |

#### LT6CPDIF function block

#### LT6CPDIF Input signals

LT6CPDIF Input signals | |||

Name | Type | Default | Description |

I3P1 | GROUP SIGNAL | – | Three phase current grp1 samples and DFT values |

I3P2 | GROUP SIGNAL | – | Three phase current grp2 samples and DFT values |

I3P3 | GROUP SIGNAL | – | Three phase current grp3 samples and DFT values |

I3P4 | GROUP SIGNAL | – | Three phase current grp4 samples and DFT values |

I3P5 | GROUP SIGNAL | – | Three phase current grp5 samples and DFT values |

I3P6 | GROUP SIGNAL | – | Three phase current grp6 samples and DFT values |

#### LT6CPDIF Output signals

LT6CPDIF Output signals | |||

Name | Type | Description | |

TRIP | BOOLEAN | Common, main, trip output signal | |

TRL1 | BOOLEAN | Trip signal from phase L1 | |

TRL2 | BOOLEAN | Trip signal from phase L2 | |

TRL3 | BOOLEAN | Trip signal from phase L3 | |

STARTRES | BOOLEAN | Start of restrained differential protection | |

STARTUNR | BOOLEAN | Start of unrestrained differential protection | |

STARTENH | BOOLEAN | Start of enhanced restrained differential protection | |

START | BOOLEAN | Common, main, start output signal | |

STL1 | BOOLEAN | Start signal from phase L1 | |

STL2 | BOOLEAN | Start signal from phase L2 | |

STL3 | BOOLEAN | Start signal from phase L3 | |

INTFAULT | BOOLEAN | Internal fault has been detected | |

EXTFAULT | BOOLEAN | External fault has been detected | |

BLK2H | BOOLEAN | Common block signal, due to 2nd harmonic | |

BLK2HL1 | BOOLEAN | Block signal due to 2nd harmonic, phase L1 | |

BLK2HL2 | BOOLEAN | Block signal due to 2nd harmonic, phase L2 | |

BLK2HL3 | BOOLEAN | Block signal due to 2nd harmonic, phase L3 | |

BLK5H | BOOLEAN | Common block signal, due to 5-th harmonic | |

BLK5HL1 | BOOLEAN | Block signal due to 5th harmonic, phase L1 | |

BLK5HL2 | BOOLEAN | Block signal due to 5th harmonic, phase L2 | |

BLK5HL3 | BOOLEAN | Block signal due to 5th harmonic, phase L3 | |

ALARM | BOOLEAN | Alarm for sustained differential current | |

OPENCT | BOOLEAN | An open CT was detected | |

OPENCTAL | BOOLEAN | Open CT Alarm output signal. Issued after a delay … | |

IDL1 | REAL | Instantaneous differential current, phase L1 | |

IDL2 | REAL | Instantaneous differential current, phase L2 | |

IDL3 | REAL | Instantaneous differential current, phase L3 | |

IDL1MAG | REAL | Magnitude of fund. freq. differential current, phase L1 | |

IDL2MAG | REAL | Magnitude of fund. freq. differential current, phase L2 | |

IDL3MAG | REAL | Magnitude of fund. freq. differential current, phase L3 | |

IBIAS | REAL | Magnitude of the bias current, common for L1, L2, L3 | |

IDNSMAG | REAL | Magnitude of the negative sequence differential current | |

#### LT6CPDIF Group settings (basic)

LT6CPDIF Group settings (basic) | |||||

Name | Values (Range) | Unit | Step | Default | Description |

Operation | Off On |
– | – | Off | Operation Off / On |

IdMin | 0.20 – 2.00 | IB | 0.01 | 0.30 | Oper – restr charact., section 1 sensitivity, multiple IBase |

IdMinHigh | 0.20 – 10.00 | IB | 0.01 | 0.80 | Initial lower sensitivity, as multiple of IBase |

tIdMinHigh | 0.000 – 60.000 | s | 0.001 | 1.000 | Time interval of initial lower sensitivity, in sec |

IdUnre | 1.00 – 50.00 | IB | 0.01 | 10.00 | Unrestrained differential current limit, multiple of IBase |

NegSeqDiffEn | Off On |
– | – | On | Off/On selection for internal / external fault discriminator |

NegSeqROA | 30.0 – 120.0 | Deg | 1.0 | 60.0 | Internal/external fault discriminator Operate Angle, degrees |

IMinNegSeq | 0.01 – 0.20 | IB | 0.01 | 0.04 | Min. value of neg. seq. curr. as multiple of IBase |

CrossBlockEn | No Yes |
– | – | No | Off/On selection of the cross -block logic |

I2/I1Ratio | 5.0 – 100.0 | % | 1.0 | 10.0 | Max. ratio of 2nd harm. to fundamental harm dif. curr. in % |

I5/I1Ratio | 5.0 – 100.0 | % | 1.0 | 25.0 | Max. ratio of 5th harm. to fundamental harm dif. curr. in % |

ChargCurEnable | Off On |
– | – | Off | Off/On selection for compensation of charging currents |

AddDelay | Off On |
– | – | Off | Off/On selection for delayed diff. trip command |

IMaxAddDelay | 0.20 – 5.00 | IB | 0.01 | 1.00 | Below limit, extra delay can be applied, multiple of IBase |

tDefTime | 0.000 – 6.000 | s | 0.001 | 0.000 | Definite time additional delay in seconds |

tMinInv | 0.001 – 6.000 | s | 0.001 | 0.010 | Inverse Delay Minimum Time. In seconds |

CurveType | ANSI Ext. inv. ANSI Very inv. ANSI Norm. inv. ANSI Mod. inv. ANSI Def. Time L.T.E. inv. L.T.V. inv. L.T. inv. IEC Norm. inv. IEC Very inv. IEC inv. IEC Ext. inv. IEC S.T. inv. IEC L.T. inv. IEC Def. Time Programmable RI type RD type |
– | – | IEC Def. Time | 19 curve types. Example: 15 for definite time delay. |

k | 0.05 – 1.10 | – | 0.01 | 1.00 | Time Multiplier Setting (TMS) for inverse delays |

IdiffAlarm | 0.05 – 1.00 | IB | 0.01 | 0.15 | Sustained differential current alarm, factor of IBase |

tAlarmdelay | 0.000 – 60.000 | s | 0.001 | 10.000 | Delay for alarm due to sustained differential current, in s |

#### LT6CPDIF Group settings (advanced)

LT6CPDIF Group settings (advanced) | |||||

Name | Values (Range) | Unit | Step | Default | Description |

EndSection1 | 0.20 – 1.50 | IB | 0.01 | 1.25 | End of section 1, as multiple of reference current IBase |

EndSection2 | 1.00 – 10.00 | IB | 0.01 | 3.00 | End of section 2, as multiple of reference current IBase |

SlopeSection2 | 10.0 – 50.0 | % | 0.1 | 40.0 | Slope in section 2 of operate-restrain characteristic, in % |

SlopeSection3 | 30.0 – 100.0 | % | 0.1 | 80.0 | Slope in section 3 of operate- restrain characteristic, in % |

p | 0.01 – 1000.00 | – | 0.01 | 0.02 | Settable curve parameter, user- programmable curve type. |

a | 0.01 – 1000.00 | – | 0.01 | 0.14 | Settable curve parameter, user- programmable curve type. |

b | 0.01 – 1000.00 | – | 0.01 | 1.00 | Settable curve parameter, user- programmable curve type. |

c | 0.01 – 1000.00 | – | 0.01 | 1.00 | Settable curve parameter, user- programmable curve type. |

OpenCTEnable | Off On |
– | – | On | Open CTEnable Off/On |

tOCTAlarmDelay | 0.100 – 10.000 | s | 0.001 | 1.000 | Open CT: time in s to alarm after an open CT is detected |

tOCTResetDelay | 0.100 – 10.000 | s | 0.001 | 0.250 | Reset delay in s. After delay, diff. function is activated |

OCTBlockEn | Off On |
– | – | On | Enable Open CT blocking function trip Off/On |

#### LT6CPDIF Non group settings (basic)

LT6CPDIF Non group settings (basic) | |||||

Name | Values (Range) | Unit | Step | Default | Description |

GlobalBaseSel | 1 – 12 | – | 1 | 1 | Selection of one of the Global Base Value groups |

NoOfUsedCTs | 2 3 4 5 6 |
– | – | 2 | Total number of 3-Ph CT sets connected to diff protection |

ZerSeqCurSubtr | Off On |
– | – | Off | Off/On for elimination of zero seq. from diff. and bias curr |

TraAOnInpCh | No Transf A 1 2 3 4 5 6 |
– | – | No Transf A | Power transformer A applied on input channel X |

RatVoltW1TraA | 1.0 – 9999.9 | kV | 0.1 | 130.0 | Transformer A rated voltage (kV) on winding 1 (HV winding) |

RatVoltW2TraA | 1.0 – 9999.9 | kV | 0.1 | 130.0 | Transformer A rated voltage (kV) on winding 2 (LV winding) |

ClockNumTransA | 0 [0 deg] 1 [30 deg lag] 2 [60 deg lag] 3 [90 deg lag] 4 [120 deg lag] 5 [150 deg lag] 6 [180 deg lag] 7 [210 deg lag] 8 [240 deg lag] 9 [270 deg lag] 10 [300 deg lag] 11 [330 deg lag] |
– | – | 0 [0 deg] | Transf. A phase shift in multiples of 30 deg, 5 for 150 deg |

TraBOnInpCh | No Transf B 1 2 3 4 5 6 |
– | – | No Transf B | Power transformer B applied on input channel X |

RatVoltW1TraB | 1.0 – 9999.9 | kV | 0.1 | 130.0 | Transformer B rated voltage (kV) on winding 1 (HV winding) |

RatVoltW2TraB | 1.0 – 9999.9 | kV | 0.1 | 130.0 | Transformer B rated voltage (kV) on winding 2 (LV winding) |

ClockNumTransB | 0 [0 deg] 1 [30 deg lag] 2 [60 deg lag] 3 [90 deg lag] 4 [120 deg lag] 5 [150 deg lag] 6 [180 deg lag] 7 [210 deg lag] 8 [240 deg lag] 9 [270 deg lag] 10 [300 deg lag] 11 [330 deg lag] |
– | – | 0 [0 deg] | Transf. B phase shift in multiples of 30 deg, 2 for 60 deg |

#### LT6CPDIF Monitored data

LT6CPDIF Monitored data | ||||

Name | Type | Values (Range) | Unit | Description |

OPENCTIN | INTEGER | – | – | Open CT on Input : 1 for input 1, 2 for input 2 |

OPENCTPH | INTEGER | – | – | Open CT in Phase : 1 for L1, 2 for L2, 3 for L3 |

IDL1MAG | REAL | – | A | Magnitude of fund. freq. differential current, phase L1 |

IDL2MAG | REAL | – | A | Magnitude of fund. freq. differential current, phase L2 |

IDL3MAG | REAL | – | A | Magnitude of fund. freq. differential current, phase L3 |

IBIAS | REAL | – | A | Magnitude of the bias current, common for L1, L2, L3 |

IDNSMAG | REAL | – | A | Magnitude of the negative sequence differential current |

NSANGLE | REAL | – | deg | Angle between local and remote neg. seq. currents |

ICHARGE | REAL | – | A | Amount of compensated charging current |

#### LDLPSCH function block

#### LDLPSCH Input signals

LDLPSCH Input signals | |||

Name | Type | Default | Description |

CTFAIL | BOOLEAN | 0 | CT failure indication from local CT supervision |

OUTSERV | BOOLEAN | 0 | Input for indicating that the terminal is out of service |

BLOCK | BOOLEAN | 0 | Block of function |

#### LDLPSCH Output signals

LDLPSCH Output signals | |||

Name | Type | Description | |

TRIP | BOOLEAN | General trip from differential protection system | |

TRL1 | BOOLEAN | Trip signal from phase L1 | |

TRL2 | BOOLEAN | Trip signal from phase L2 | |

TRL3 | BOOLEAN | Trip signal from phase L3 | |

TRLOCAL | BOOLEAN | Trip from local differential function | |

TRLOCL1 | BOOLEAN | Trip from local differential function in phase L1 | |

TRLOCL2 | BOOLEAN | Trip from local differential function in phase L2 | |

TRLOCL3 | BOOLEAN | Trip from local differential function in phase L3 | |

TRREMOTE | BOOLEAN | Trip from remote differential function | |

DIFLBLKD | BOOLEAN | Local line differential function blocked | |

#### LDLPSCH Non group settings (basic)

LDLPSCH Non group settings (basic) | |||||

Name | Values (Range) | Unit | Step | Default | Description |

Operation | Off On |
– | – | Off | Operation Off / On |

TestModeSet | Off On |
– | – | Off | Test mode On/Off |

ReleaseLocal | Block all Release local | – | – | Block all | Release of local terminal for trip under test mode |