Use of Safety Relays?

I searched and found plenty of information. Try again.

ah come on now. Not another "use google" response. Please this is becoming more than a joke at this stage. Are you on the take from Google?

A safety relay is used when some machine might injure a person if kept in operation. Safety relays are rated and designed so that they will fail in known conditions to minimize the risk that a failed safety system would erroneously permit operation and thus cause a person to be injured.

Depending on the application you can have a low voltage relay operating high voltage switchgear with low voltage safety switches all keeping high voltage away from the operator ie all relays & safteycutouts in 12volt switching any thing from 110v,220v to what have you, another application is switching lots of lights on at once, you have your low voltage low amperage light switch operating say 220volt relay that in turn will operate a high amperage switchgear or more than one switchgear all at once.

I hope this clarifies what they do.

Bazzer

We use safety relays in the elevator and escalator world. Safety devices are configured in series circuit with the relay coil fed from the "end" of the series of safety switches and when one opens the relay de-energizes. A normally open contact on the relay when closed upon energizing of the relay coil passes a signal to the controller that the safety circuit is made up. It places a mechanically opened device that reacts to safety inputs in control of the operating motor. We use a relay because should the device fail, it almost always fails in the open condition. The unit shuts down but no one gets hurt, maybe stuck but safe. Joe