ANSI IEC 60617 Description

21FL FLOC Fault locator

21G Z< Three-phase underimpedance protection, low-set stage

24 U/f> Overexcitation, low-set stage

24 U/f>> Overexcitation, high-set stage

25 SYNC Synchro-check/ voltage check, stage 1

25 SYNC Synchro-check/ voltage check, stage 2

27 3U< Three-phase undervoltage, low-set stage

27 3U<< Three-phase undervoltage, high-set stage

27, 47, 59U1< U2> U1>

Phase-sequence voltage protection, stage 1

27, 47, 59U1< U2> U1>

Phase-sequence voltage protection, stage 2

32 P← Three-phase underpower or reverse power, stage 1

32 P← Three-phase underpower or reverse power, stage 2

32 P← Three-phase underpower or reverse power, stage 3

32P/32Q P>→/Q>→ Three-phase directional overpower, stage 1

32P/32Q P>→/Q>→ Three-phase directional overpower, stage 2

32P/32Q P>→/Q>→ Three-phase directional overpower, stage 3

37 3I< Three-phase non-directional undercurrent, stage 1

37 3I< Three-phase non-directional undercurrent, stage 1

37 3I< Three-phase non-directional undercurrent, stage 2

40 X< Three-phase underexcitation protection, low-set stage

40 X<< Three-phase underexcitation protection, high-set stage

46 I2> Negative-phase sequence, low-set stage

46 I2>> Negative-phase sequence, high-set stage

46 ΔI> Phase discontinuity

46R Phase reversal protection

48, 14, 66 Is²t, n<Three-phase start-up supervision for motors (incl. I2t and speed device modes, and start-up counter)

49F 3Ith> Three-phase thermal protection for cables

49M/49G/49TThree-phase thermal protection for devices (motors, generators and transformers)

50N I0>>> Non-directional earth-fault, instantaneous stage

50N/51N I0>> Non-directional earth-fault, high-set stage

50P/51P 3I>>> Three-phase non-directional overcurrent, instantaneous stage

51 3I> Three-phase non-directional overcurrent, low-set stage

51C, 37C, 68C 3I> 3I< Three-phase overload protection for shunt capacitor banks

51N I0>/SEFNon-directional earth-fault, low-set stage (or SEF=sensitive earth-fault protection)

51NC 3ΔI> Three-phase current unbalance protection for H-bridge connected shunt

capacitor banks

51NC ΔI> Current unbalance protection for shunt capacitor banks

51P-1 3I> Three-phase non-directional overcurrent, low-set stage

51V I(U)> Voltage-dependent overcurrent, low-set stage

51V I(U)>> Voltage-dependent overcurrent, high-set stage

551P-2 3I>> Three-phase non-directional overcurrent, high-set stage

59 3U> Three-phase overvoltage, low-set stage

59 3U>> Three-phase overvoltage, high-set stage

59N U0> Residual overvoltage, low-set stage

59N U0>> Residual overvoltage, High-set stage

59N U0>>> Residual overvoltage, instantaneous stage

60 FUSEF Fuse failure supervision

67-1 3I>→ Three-phase directional o/c, low-set stage

67-2 3I>>→ Three-phase directional o/c, high-set stage

67 3I>>>→ Three-phase directional o/c, instantaneous stage

67N I0>>>→ Directional earth-fault, instantaneous stage

67N I0>>→ Directional earth-fault, high-set stage

67N I0>→ Directional earth-fault, low-set stage

67N/51N I0>→ /SEF Directional earth-fault, low-set stage (or SEF=sensitive earth-fault protection)

68 3I2f> Three-phase transformer inrush and motor start-up current detector

79 0 → 1 Auto-reclosure

81U/81O f</f>, df/dt Underfrequency or overfrequency, stage 1 (incl. rate of change)

87G 3DI> Stabilized three-phase differential protection for generators

87G/87M 3DI>High-impedance or flux-balance based differential protection for generators and motors

87N ΔI0>, REF High-impedance based restricted earth-fault

87T 3ΔI>, 3ΔI>> Stabilized three-phase differential protection for transformers

87TN ΔI0> Stabilized restricted earth-fault, stage A