Power Loss On Off Switch 2

[NicSacco]

I am looking for a swith, mountable to the front of an enclosure, that when power is lost or inturupted, Automatically switches to the "off" postion and has to phisically be turned on. Any idea's would be helpful.

 

[busbar]

Search on "3-wire control" circuits.

 

[rbulsara]

Use two push buttons and a relay. Wire them like a simple motor controller circuit (latching and reset circuit).

N.O. pushbutton =(Start or 'on' or 'reset') and one N.C. push button =(stop or 'off')wired in series with the relay coil and one N.O. holding (latching) contact connected across the N.O. (start) contact.

Wire the load through remaining realy contact(s).

 

[DanDel]

Or, for heavy duty industrial circuits, use an ANSI device type 86, lockout relay and associated wiring. Check with Electroswitch.

http://www2.gocci.com/electroswitch/electroswitchesandrelays/default.htm

 

[jbartos]

Suggestion: A circuit breaker (may be a little luxury) with an Undervoltage Relay (UVR) (ANSI Device No. 27) release would do the job. However, it is necessary to have the power supply to come back on to be able to reset the circuit breaker since it is latched by UVR on no power supply on the line side.

 

[NicSacco]

I am thinking mor on the line of a switch that turns your dryer on. When you turn or push it, the dryer kicks on, but if ther is a loss of power, you need to physically restart the dryer to get it started again. I am just now sure how this is accomplished and thought I would ask here before I went and ripped my dryer apart.

thanks for the suggestions so far...keep 'em coming

 

[DanDel]

NicSacco, all you are talking about is a simple magnetic relay with a holding contact. When you press the start button, it closes the relay and also a holding contact which keeps the relay coil circuit energized. Upon a loss of power, the relay opens and must be closed again manually.

 

[jbartos]

Comment on the previous posting: This solution may be even more expensive than the circuit breaker with an undervoltage release. I just assume the power will not or should not be interrupted so often.
Incidentally, Busbar second posting that addresses 3-wire control circuit is probably referring to a magnetic contactor or starter circuit. Any better control product catalog has it included, e.g. Square D Digest catalog, General Electric control catalog, etc.
Visit

http://fie.engrng.pitt.edu/fie2002/papers/1499.pdf

etc. for more info