Signal relays are generally used for monitoring and protection, and are widely used in secondary protection circuits of power distribution high-voltage cabinets. For example, if the temperature of the transformer oil exceeds 85 degrees, a normally open contact on the temperature monitoring indicator is closed. This contact is connected to the coil circuit of the signal relay. Therefore, if there is a signal, the signal relay coil will be pulled in and the signal relay will act. , the word "light" is dropped, and the high-voltage switch is disconnected to remove the load of the transformer, thereby protecting the transformer. However, there are also many types of signal relays, some of which are directly buzzing or flashing as an alarm signal.

When the secondary protection circuit operates, the signal relay will be activated. It informs the person concerned exactly which protection is at fault, and it has a clear boot logo on its exterior.

A power relay is a device that can produce a jump in one or more electrical output circuits when the input quantity (or excitation quantity) meets certain specified conditions. It can be used in the neutral point directly grounded system as a directional element for zero-sequence current protection.

The above is the whole content of the difference between signal relays and power relays, and the data sheet should be carefully checked when selecting models. Each relay has its own indicators, and the relay is selected according to the design circuit requirements.