ECN Forum Forums General Topics of the Trade General Discussion Area What is the primary purpose of a relay?

Relay, cintactor...the difference is only in scale!

Well....almost. Most 'contactors' have only "normally open" contacts. A relay typically will also have "normally closed" contacts. These contacts will let the relay operate something when the relay is "off". A common example is your typical alarm system; cut a wire, and you trigger the alarm.

Now...take a contactor, add overloads... and you now have a "starter." Add a disconnect switch, and it's now a "combination starter."