3 Phase Current Balance Protection Relays

A three phase current balance protection relay continuously monitors a three phase AC current through current transformers, tripping upon an unbalanced load condition. The output relay trips when the monitored current is outside of the user adjustable limit and the LED ceases to illuminate indicating a fault condition. The trip point is adjustable from 3% to 20% of the nominal current through the front control knob. The relay also has a built-in time delay, adjustable from 0.1 to 10 seconds, used to avoid nuisance tripping. The output relay is set to de-energise in the unbalanced condition ensuring the protection relay is failsafe. The relay is auxiliary powered and is available with an output to either open on fault or close on fault.

Key Terms: CST-100 - Current Balance - Protection Relay