Start-Restart safety switch

[John Schindler]

A lot of safety rules require an interlock, such as a switch on a door or
gate, to shut down equipment when the door is opened. The equipment is not
supposed to restart after a shutdown like this, but require the door be
closed, and some other operation (like a pushbutton) restart the gear.

I have seen some products that perform some of these functions, but they
don't contain the start-restart switch, and some of them have logic or other
switches that make them look a bit failure prone themselves. It would be
nice if there was a package that contained a latching push button that draws
power through the interlock switch, and also had an indicator light.

Does anyone know of such as switch, or keywords to use in a search?

Thanks in advance,

John

 

[John Schindler]

I use a relay. A push button closes the circuit to operate the relay. A
set of contacts on the relay
are in parallel with the switch so once operated, the relay stays
operated. The door switch can be
in series with the relay coil so that opening the door releases the relay

You would then have to close the door and push the button to operate the
relay.

Cheers
Bill K7NOM

That looks like the solution,

Thanks for your help,

John

 

[Bill Janssen]

John Schindler wrote:

A lot of safety rules require an interlock, such as a switch on a door or
gate, to shut down equipment when the door is opened. The equipment is not
supposed to restart after a shutdown like this, but require the door be
closed, and some other operation (like a pushbutton) restart the gear.

I have seen some products that perform some of these functions, but they
don't contain the start-restart switch, and some of them have logic or other
switches that make them look a bit failure prone themselves. It would be
nice if there was a package that contained a latching push button that draws
power through the interlock switch, and also had an indicator light.

Does anyone know of such as switch, or keywords to use in a search?

Thanks in advance,

John




I use a relay. A push button closes the circuit to operate the relay. A

set of contacts on the relay
are in parallel with the switch so once operated, the relay stays
operated. The door switch can be
in series with the relay coil so that opening the door releases the relay

You would then have to close the door and push the button to operate the
relay.

Cheers
Bill K7NOM