GE T35

CHAPTER 2: PRODUCT DESCRIPTION SPECIFICATIONS
T35 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL 2-19
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Pickup level: 0.020 to 30.000 pu in steps of 0.001
Dropout level: 97% to 98% of pickup
Level accuracy:
0.1 to 2.0 × CT: ±0.5% of reading or ±0.4% of rated (whichever is greater)
> 2.0 × CT: ±1.5% of reading > 2.0 × CT rating
Curve shapes: IEEE Moderately/Very/Extremely Inverse; IEC (and BS) A/B/C and Short Inverse; GE IAC Inverse,
Short/Very/ Extremely Inverse; I
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t; FlexCurves™ (programmable); Definite Time (0.01 s base
curve)
Curve multiplier: Time Dial = 0.00 to 600.00 in steps of 0.01
Reset type: Instantaneous/Timed (per IEEE)
Curve timing accuracy at 1.03 to 20 x pickup:
±3.5% of operate time or ±½ cycle (whichever is greater) from pickup to operate
Voltage restraint: Modifies pickup current for voltage in the range of 0.1 < V < 0.9 VT Nominal in a fixed linear rela-
tionship
PHASE/GROUND IOC
Current: Phasor only
Pickup level: 0.020 to 30.000 pu in steps of 0.001
Dropout level: 97 to 98% of pickup
Level accuracy:
0.1 to 2.0 × CT rating: ±0.5% of reading or ±0.4% of rated (whichever is greater)
> 2.0 × CT rating: ±1.5% of reading
Overreach: <2%
Pickup delay: 0.00 to 600.00 s in steps of 0.01
Reset delay: 0.00 to 600.00 s in steps of 0.01
Operate time: <16 ms at 3 × pickup at 60 Hz (Phase/Ground IOC)
<20 ms at 3 × pickup at 60 Hz (Neutral IOC)
Timer accuracy: ±3% of operate time or ±1/4 cycle (whichever is greater)
TRANSFORMER HOTTEST-SPOT TEMPERATURE
Operating quantity: computed temperature in °C
Pickup level: 50 to 300°C in steps of 1
Dropout level: 1°C below pickup
Pickup delay: 0 to 30000 min. in steps of 1
TRANSFORMER AGING FACTOR
Operating quantity: computed aging acceleration factor (pu)
Pickup level: 1 to 10 pu in steps of 0.1
Pickup delay: 0 to 30000 min. in steps of 1
TRANSFORMER LOSS OF LIFE
Operating quantity: computed accumulated transformer loss of life, in hours
Pickup level: 0 to 500000 hours in steps of 1
UNDERFREQUENCY
Minimum signal: 0.10 to 1.25 pu in steps of 0.01
Pickup level: 20.00 to 65.00 Hz in steps of 0.01
Dropout level: pickup + 0.03 Hz
Level accuracy: ±0.001 Hz
Time delay: 0 to 65.535 s in steps of 0.001
Timer accuracy: ±3% of operate time or ±1/4 cycle (whichever is greater)
Operate time: typically 4 cycles at 0.1 Hz/s change
typically 3.5 cycles at 0.3 Hz/s change
typically 3 cycles at 0.5 Hz/s change
Typical times are average operate times including variables such as frequency change instance, test method, and so on, and can vary by
±0.5 cycles.