ABB REF 541 Product Manual page 30

30
Feeder Terminal
Operation accuracy
Trip time
Reset time
Reset ratio, typically
Retardation time
Operate time accuracy
Underfrequency or overfrequency protection, 5 stages, Freq1St1... Freq1St5, f1 ... f5 (81-1 ... 81-5)
Operation mode
Undervoltage limit for blocking
Start value for under-/overfrequency prot.
Operate time for under-/overfrequency prot.
Start value for df/dt protection
Operate time for df/dt protection
Operation accuracy
Start time
Reset time
Operate time accuracy
REF 541, REF 543, REF 545.
Note! The values below apply when f/fn = 0.95...1.05
± 2.5% of set value or ± 0.01 x Un
U2> operation:
Injected negative-seq. voltage = 1.1 x start value:
internal time < 42 ms
total time < 50 ms
U1< operation:
Injected positive-seq. voltage = 0.50 x start value:
internal time < 32 ms
total time < 40 ms
U1> operation:
Injected positive-seq. voltage = 1.1 x start value:
internal time < 42 ms
total time < 50 ms
70...1030 ms (depends on the minimum pulse width
set for the TRIP output)
U2> operation: 0.96
U1< operation: 1.04
U1> operation: 0.99
< 45 ms (for all operations)
± 2% of set value or ± 20 ms
Not in use
f</f> 1 timer
f</f> 2 timers
f</f> OR df/dt>
f</f> AND df/dt>
f</f> OR df/dt<
f</f> AND df/dt<
0.30...0.90 x Un
25.00...75.00 Hz
0.10...300.00 s
0.2...10.0 Hz/s
0.12...300.00 s
Under-/overfrequency (f</f>): ±10 mHz
Frequency rate of change (df/dt);
real df/dt < ±5 Hz/s: ±100 mHz/s
real df/dt < ±15 Hz/s: ±2.0% of real df/dt
Undervoltage blocking: ±1.0% of set value
Total start times at fn = 50 Hz:
Frequency measurement < 100 ms
Df/dt measurement < 120 ms
140...1000 ms (depends on the minimum pulse width set
for the trip output)
±2% of set value or ±30 ms
1MRS750443-MBG