sepam 20 user manual - Schneider Electric

3
Protection functions Remanent undervoltage
ANSI code 27R
3/6
MT10875
Operation
This protection is single-phase:
b it picks up when the U21 phase-to-phase voltage is less than the Us set point
b the protection includes a definite time delay.
Block diagram
U21
(or V1)
Characteristics
Us set point
Setting 5 % Unp to 100 % Unp
Accuracy (1) ±2 % or 0.005 Unp
Resolution 1 %
Drop-out/pick-up ratio 103 % ±2.5 %
Time delay T
Setting 50 ms to 300 s
Accuracy (1) ±2 %, or ±25 ms
Resolution 10 ms or 1 digit
Characteristic times
U < Us
Operation time < 40 ms
Overshoot time < 20 ms
Reset time < 30 ms
(1) In reference conditions (IEC 60255-6).
T
0
time-delayed output
“pick-up” signal
PCRED301005EN - 06/2008