GE 745 Instruction Manual page 27

CHAPTER 2: OVERVIEW
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
Solid state output operate time:
at 1.2 × pickup: ......................... 22 to 30 ms
at 2.0 × pickup: ......................... 18 to 26 ms
at 4.0 × pickup: ......................... 11 to 19 ms
Relay outputs 2 to 5 operate time:
at 1.2 × pickup: ......................... 28 to 36 ms
at 2.0 × pickup: ......................... 24 to 32 ms
at 4.0 × pickup: ......................... 17 to 25 ms
PHASE / NEUTRAL / GROUND / NEGATIVE SEQUENCE TIME OVERCURRENT
Pickup level: ......................................................0.05 to 20.00 × CT in steps of 0.01
Dropout level: ...................................................97 to 98% of pickup
Curve shapes: ..................................................ANSI extremely/very/moderately/normally inverse;
Curve multiplier: .............................................0.00 to 100.00 in steps of 0.01
Reset type:.........................................................instantaneous or linear
Level accuracy: ...............................................per current input
Timing accuracy: ...........................................±3% of trip time or ±20 ms (whichever is greater) at ≥ 1.03
PHASE / NEUTRAL / GROUND / NEGATIVE SEQUENCE INSTANTANEOUS OVERCURRENT
Pickup level: ......................................................0.05 to 20.00 × CT in steps of 0.01
Dropout level: ...................................................97 to 98% of pickup
Time delay:........................................................0 to 60000 ms in steps of 1
Level accuracy: ...............................................per current input
Solid state output operate time:
at 1.2 × pickup: ......................... 22 to 30 ms
at 2.0 × pickup: ......................... 18 to 26 ms
at 4.0 × pickup: ......................... 11 to 19 ms
Relay outputs 2 to 5 operate time:
at 1.2 × pickup: ......................... 28 to 36 ms
at 2.0 × pickup: ......................... 24 to 32 ms
at 4.0 × pickup: ......................... 17 to 25 ms
RESTRICTED GROUND FAULT
Number of elements:....................................2
Minimum pickup: ............................................0.02 to 20.00 × CT in steps of 0.01
Dropout level: ...................................................97 to 98% of pickup
Slope range:......................................................0 to 100% in steps of 1
Pickup delay: ....................................................0.00 to 600.00 s in steps of 0.01
Solid-state output operating time:
Relay outputs 2 to 5 operating time:
UNDERFREQUENCY
Number of elements:....................................2
Operating current pickup: 0.05 to 1.00 × CT in steps of 0.01
Operating voltage pickup: 0.10 to 0.99 × VT in steps of 0.01
Pickup level: ......................................................45.00 to 59.99 Hz in steps of 0.01
Dropout level: ...................................................pickup + 0.03 Hz
definite time (0.1 s base curve); IEC curve A/B/C and short;
FlexCurve™ A/B/C (programmable curves); IAC extreme/
very/inverse/short
× pickup
at 1.1 × pickup: 30 to 50 ms
at 10 × pickup: 20 to 30 ms
(delay set at 0.0 s)
at 1.1 × pickup: 30 to 50 ms
at 10 × pickup: 20 to 30 ms
(delay set at 0.0 s)
SPECIFICATIONS
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