ABB RET 541 - Page 29

Three-phase overvoltage protection, high-set stage, OV3High, 3U>>
Start voltage
Operate time
Operation mode
Measuring mode
Operation hysteresis
0.10…1.60 x Un
0.05…300.0 s
Not in use
Definite time
Phase-to-phase voltages; peak-to-peak measurement
Phase-to-phase voltages; fundamental freq. measurement
Phase-to-earth voltages; fundamental freq. measurement
1.0...5.0%
Operation accuracy
Start time:
- injected voltages
- internal time
- total time
Reset time
Reset ratio
Retardation time
Operate time accuracy at DT mode
Note! The values below apply when f/fn = 0.95...1.05
±2.5% of set value
= 1.1 x start voltage
<42 ms
<50 ms
40...1000 ms (depends on the minimum pulse width set for
the trip output)
0.96 (range 0.95...0.99)
< 50 ms
±2% of set value or ±20 ms
Three-phase undervoltage protection, low-set stage, UV3Low, 3U<
Start voltage
Operate time
Time multiplier
Operation mode
Measuring mode
Operation hysteresis
0.10…1.20 x Un
0.1…300.0 s
0.1…1.0
Not in use
Definite time
C curve
Phase-to-phase voltages; peak-to-peak measurement
Phase-to-phase voltages; fundamental freq. measurement
Phase-to-earth voltages; fundamental freq. measurement
1.0...5.0%
Operation accuracy
Start time:
- injected voltages
- internal time
- total time
Reset time
Reset ratio
Retardation time
Operate time accuracy at DT mode
Accuracy class index E at IDMT mode,
typically
Note! The values below apply when f/fn = 0.95...1.05
±2.5% of set value or ±0.01 x Un
<0.5 x start voltage:
<32 ms
<40 ms
40...1000 ms (depends on the minimum pulse width set for
the trip output)
1.04 (range 1.01...1.05)
< 60 ms
±2.5% of set value
±35 ms
Transformer Terminal RET 541, RET 543, RET 545
1MRS755543
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