Control relay classification method

There are many types of control relays, and the classification methods are various. The most common one is to classify according to its principle of action:

1. Voltage relay: mainly used for motor loss (undervoltage) protection and overvoltage protection.

2. Current relays: for overload and short circuit protection of motors (generators), magnetic field control and loss of field protection for generators and DC motors.

3. Intermediate relay: Its purpose is to increase the number of control loops or to expand the control signal by intermediate conversion.

4. Time relay: time control for AC/DC motor (generator) and program control of process.

5. Thermal relay: Used for overload protection of AC motors (generators).

6. Temperature relay: mainly used for motor (generator) overheat protection or temperature control devices.

7. Speed ​​relay and brake relay: used for reverse braking and energy braking of induction motors.

8. Special relays: There are many types, including reed relays, pulse relays, pressure relays, and acoustic and optical relays. They are mainly used in automatic detection and automatic control systems of generator sets.