What is pointing relay

The relay protection and automation for operational circuits, control circuits and signaling commonly used devices such as a pointing relays (EDM) (another name - blinker). When triggered, the blinker is "falling flag" that indicates the personnel that the circuit at the site emergency situation has occurred. In this article I will tell you about the application and principle of operation of this device.

Why you need a pointing relay

The main purpose of such devices - is a duty to inform the operating personnel about the contingency situation.

For example, operational mobile teams, who arrived at the substation, first make inspection of equipment and as a result, can see, for example, that feeder-335 disconnected from the overcurrent (overcurrent), A reclosure (auto-reclosing) successfully incorporated in the feeder work. All the information they receive through the relay actuation index.

How does blinker

The basic principle of index relay various modifications concluded as follows: the mechanism is cocked blinker and a spring latch is retained only until such time as the electromagnet is located beside not work and will not break lock. Thereby triggering mechanism occurs:

existing modification

There are a number of different modifications of index relay. The most popular varieties, characterized by high reliability, are presented in the table below:

How to connect

For each type of switch manufacturer provided wiring diagram:

conclusions

Pointing relay, regardless of the type of performance and modifications, is an excellent fixative past event, and work to protect circuits or signaling. The use of these devices allows you to obtain information about the occurred event and evaluate the correct operation of the protection or alarm object.

If the article is to provide you with useful and interesting, then place the thumbs up. Thank you for your attention!