Under Voltage Relay

SP-0 Mod D

The input consists of a star-connected three-phase transformer, followed by a rectifier bridge. R4 and V9 limit the voltage to approx. 27 V = to the other electronics. The relay K1 is controlled by the
comparator V17 which receives a reference from the voltage divider R12, R8.

The measuring voltage is taken from the voltage divider R5, R6. This is selected so that the comparator does not switch on the relay until the switch-on voltage is sufficiently high.

The relay drops off when the voltage after R4 has dropped to 5-6 Volts. R1, R2 and R3 are varistors, which come into operation at approx. 330/600 V~, for the 110/220 Volt version respectively.

Normal connection and voltage at all phases:

Typical applications

Interlocking of switch controls in power and transformer stations. Voltage indication on lines / busbars.

Electrical specifications

Order information

Art.nr. Type Assembly
SP0 MOD.D 110V 50 / 60Hz
DIN 35
P0 MOD.D 220V 50 / 60Hz
DIN 35

DIN 35