GE 745 - 2.2 Specifications; 2.2.1 Applicability; 2.2.2 Inputs

CHAPTER 2: OVERVIEW SPECIFICATIONS
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL 2–5
2.2 Specifications
2.2.1 Applicability
TRANSFORMERS AND FREQUENCY
Transformers:...................................................two-winding or three-winding
Frequency:.........................................................50 or 60 Hz nominal
Frequency tracking:......................................40 to 65 Hz for 0.05 × CT < current ≤ 1 × CT
5 to 65 Hz for current > 1 × CT
2 to 65 Hz for voltage > 50% of VT (only if voltage sensing
is enabled)
2.2.2 Inputs
CONTROL POWER
Options:...............................................................LO/HI (specified when ordering)
LO range:............................................................20 to 60 V DC; 20 to 48 V AC at 48 to 62 Hz
HI range:.............................................................90 to 300 V DC; 70 to 265 V AC at 48 to 62 Hz
Power:..................................................................30 VA nominal, 40 VA maximum
Total loss of voltage ride-through time (0% control power): 16.7 ms
Fuse current rating:.......................................3.15 A (fuse not accessible)
Fuse type: ..........................................................5 × 20 mm slow-blow Littelfuse, high breaking capacity;
model 2153.15
PHASE CURRENT INPUT
Source CT:..........................................................1 to 50000 A primary; 1 or 5 A secondary
Relay input:.......................................................1 A or 5 A (specified at order)
Burden:................................................................less than 0.2 VA at rated load per phase
Conversion range:..........................................0.02 to 46 × CT at 50/60 Hz nominal frequency
Accuracy at < 4 × CT: ...................................±0.25% of 4 × CT (±0.01 × CT) at 50/60 Hz nominal
frequency
Accuracy at ≥ 4 × CT: ...................................±0.5% of 46 × CT (±0.2 × CT) at 50/60 Hz nominal
frequency
Overload withstand:......................................1 second at 80 times rated current; 2 seconds at 40 times
rated current; continuous at 3 times rated current
GROUND CURRENT INPUT
Source CT:..........................................................1 to 50000 A primary, 1 or 5 A secondary
Relay input:.......................................................1 A or 5 A (specified at order)
Burden:................................................................less than 0.2 VA at rated load
Conversion range:..........................................0.02 to 46 × CT
Accuracy at < 4 × CT: ...................................±0.25% of 4 × CT (±0.01 × CT)
Accuracy at ≥ 4 × CT: ...................................±0.5% of 46 × CT (±0.2 × CT)
Overload withstand:......................................1 second at 80 times rated current; 2 seconds at 40 times
rated current; continuous at 3 times rated current
VOLTAGE INPUTS
Source VT:..........................................................2 to 600 kV / 60 to 120 V
Source VT ratio:...............................................1 to 5000 in steps of 1
Relay input:.......................................................60 to 120 V phase-neutral
Burden:................................................................less than 0.025 VA at 120 V
Maximum continuous input: 273 V
Maximum accuracy input: 260 V (full-scale)