Grounding, phase sequence, phase failure blocking relay

The coil of the grounding relay is connected to a zero-sequence current transformer (cable type, busbar type, or zero-sequence current filter composed of three-phase current transformers).
Phase sequence protection: When the phase sequence of the three-phase electricity changes, the relay will also stop working. For example, if we use it in the disconnected state, it is connected in series in the external control loop, and the control loop cannot be connected.

The phase loss protector is also called the motor phase loss protector or the power supply phase loss protector. This kind of detection current control can be called phase failure relay, overload relay, overcurrent protection relay, etc., and can also be called motor protector, compressor protector, etc. according to the function, for AC 45 ~ 60Hz, voltage 24V to 380V In the power supply circuit of the electric motor, the control circuit of the motor is composed of switching appliances such as AC contactors.

Locking refers to "self-locking". After the relay is energized, it automatically locks its state and keeps the circuit connected. Even if the control current is cut off at this time, its state will not be changed. That is to say, when the power is turned on, the control current is cut off, and the connected state remains on unless the unlock button is pressed.