Relays РЗД-1 provide protection of electric motors in case of following situations:
• inadmissible voltage asymmetry or phase failure of three-phase AC circuit on 6 (10) kV or 380 V side of the supply transformer;
• motor overheating (overload)
Relay РЗД-1 prohibits starting the motor under inadmissible decrease of isolation resistance of its windings in relation to its case
RRelays РЗД-1 also have versions with additional functions:
• thermal protection (if posistors in the motor windings are available);
• сontrol of process parameters, for example, pipeline pressure;
• surge current control of the mechanism operating in stopping mode;
• information output for communication with controller or computer.
The unit has personnel protection device installed in the control circuits to protect from electric shock, to protect the network from short-circuits and overloads, and to prevent fires resulting from the occurrence of large earth leakage currents and shortings.