sepam 20 user manual - Schneider Electric
sepam 20 user manual - Schneider Electric
sepam 20 user manual - Schneider Electric
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Protection functions Phase-to-neutral undervoltage<br />
ANSI code 27S<br />
PCRED301005EN - 06/<strong>20</strong>08<br />
MT10874<br />
Operation<br />
This protection is three-phase:<br />
b it picks up when one of the 3 phase-to-neutral voltages drops below the Vs set<br />
point<br />
b it has 3 independent outputs available for the control matrix<br />
b it is operational if the number of VTs connected is V1, V2, V3 or U21, U32 with<br />
measurement of V0.<br />
Block diagram<br />
V1<br />
V2<br />
V3<br />
V1 < Vs<br />
V2 < Vs<br />
V3 < Vs<br />
Characteristics<br />
Vs set point<br />
Setting 5 % Vnp to 100 % Vnp<br />
Accuracy (1) ±2 % or 0.005 Vnp<br />
Resolution 1 %<br />
Drop-out/pick-up ratio<br />
Time delay T<br />
103 % ±2.5 %<br />
Setting 50 ms to 300 s<br />
Accuracy (1) ±2 %, or ±25 ms<br />
Resolution<br />
Characteristic times<br />
10 ms or 1 digit<br />
Operation time pick-up < 35 ms (typically 25 ms)<br />
Overshoot time < 35 ms<br />
Reset time<br />
(1) In reference conditions (IEC 60255-6).<br />
< 40 ms<br />
T<br />
T<br />
T<br />
1<br />
0<br />
0<br />
0<br />
time-delayed output<br />
time-delayed output<br />
time-delayed output<br />
“pick-up” signal<br />
3/7<br />
3
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