What Is a Voltage Relay?
A voltage relay is an electronic control device that has a control system (also called an input loop) and a controlled system (also called an output loop). It is usually used in an automatic control circuit. It actually uses a smaller current to control the comparator. An "automatic switch" for high currents. Therefore, it plays the role of automatic adjustment, safety protection and conversion circuit in the circuit. Mainly used in relay protection devices for generators, transformers and transmission lines, as a starting element for overvoltage protection or low voltage blocking.
The voltage relay is a measuring relay with an input quantity and a characteristic quantity as a voltage, and is divided into an over-voltage relay and an under-voltage relay. The former acts as the voltage value increases to reach the setting value, and then moves to the post-moving state; the latter acts as the voltage value decreases to reach the setting value, and then is in the released state. The voltage relay has an electromagnetic type and a transistor type.
From the form, it can be divided into: electromagnetic voltage relay and static voltage relay (integrated circuit voltage relay). From the structure type, it can be divided into: a convex fixed structure, a convex plug type structure, an embedded plug structure, a rail type structure and the like.
From the type of voltage action, it can be divided into: overvoltage relay and low voltage (undervoltage) relay. From the way of use, it can be divided into: auxiliary source and auxiliary source voltage relay.
In addition, DC voltage relays, three-phase voltage relays, negative sequence voltage relays, and voltage relays with delay functions are common.