Entry way 2 hour override switch... - Contractor Talk - Professional Construction and Remodeling Forum

hbelectric · 09-12-2009, 08:17 PM

I need a 2 hour override for lighting in medical building, lights operate off a 20 amp contactor. I have no idea where to start looking...something push button would be nice.

480sparky · 09-12-2009, 08:30 PM

Leviton 6652-1I.

mrmike · 09-13-2009, 06:42 AM

I'm thinking you have many lights to operate, as you said they were on a 20 amp contactor so you will need a timer with heavy duty contacts............. If you want a push button type switch?, you will have to wire it to pull in a timer relay to operate that 20 amp contactor. Need more Specifics !

480sparky · 09-13-2009, 07:42 AM

Quote:

Originally Posted by mrmike

I'm thinking you have many lights to operate, as you said they were on a 20 amp contactor so you will need a timer with heavy duty contacts............. If you want a push button type switch?, you will have to wire it to pull in a timer relay to operate that 20 amp contactor. Need more Specifics !

I'm gonna say it's the lighting circuits that are 20 amps, not the coil on the contactor. I've never seen a lighting contactor coil draw more than an amp.

TimelessQuality · 09-13-2009, 08:11 AM

Similar situation..folks place.

Have a gas well that needs saltwater pumped periodically..as needed. We have a pressure switch on a volume tank that will start it..but it needs to run for like an hour after the pressure comes back up.

Timer won't work... need some thing like a relay w/delay?

BTE · 09-13-2009, 12:42 PM

Sparky is right. If you install just a push button, you'll need to install some type of timing device that hooks up to a 7-day timer. It is best to install a twist timer that mechanically times itself out that is wired to a lighting contactor.

hbelectric · 09-13-2009, 12:47 PM

Quote:

Originally Posted by mrmike

I'm thinking you have many lights to operate, as you said they were on a 20 amp contactor so you will need a timer with heavy duty contacts............. If you want a push button type switch?, you will have to wire it to pull in a timer relay to operate that 20 amp contactor. Need more Specifics !

I'm using the 365 day time clock on the right in the picture, so basically you are saying this levinton 6652 push button, will most likely need a relay to close the lighting contactor. If this is the case, not a problem.

firemike · 09-13-2009, 01:22 PM

Quote:

Originally Posted by hbelectric

I need a 2 hour override for lighting in medical building, lights operate off a 20 amp contactor. I have no idea where to start looking...something push button would be nice.

We used to use something like this in the stores we did. just a simple off-delay relay that controls the coil of the contactor.

http://www.grainger.com/Grainger/items/1EJP3

Turn the light switch off and the contactor turns the lights off after predetermined amount of time (ie. Give the employees enough time to get out of the building before all the lights went off)

480sparky · 09-13-2009, 01:51 PM

Quote:

Originally Posted by hbelectric

I'm using the 365 day time clock on the right in the picture, so basically you are saying this levinton 6652 push button, will most likely need a relay to close the lighting contactor. If this is the case, not a problem.

You can put the 7-day timer and the 2-hour switch in parallel with each other. That way, either one will turn on the lights as needed. Run them with the same circuit to control the same relay.

hbelectric · 09-13-2009, 02:29 PM

Quote:

Originally Posted by 480sparky

You can put the 7-day timer and the 2-hour switch in parallel with each other. That way, either one will turn on the lights as needed. Run them with the same circuit to control the same relay.

Yeah I understand, I know some of these timers won't close contactors. But this one says its good for inductive loads/motor loads.

mrmike · 09-13-2009, 03:45 PM

Quote:

Originally Posted by 480sparky

I'm gonna say it's the lighting circuits that are 20 amps, not the coil on the contactor. I've never seen a lighting contactor coil draw more than an amp.

???? Lighting circuits are never across the coil of the Contactor. The lighting is across the contacts of the Contactor. The coil is usually pulled in by a relay or remote switch, etc- most times thru a Photocell. We had multiple outside area lights turned on by one contactor with just one photocell to turn them on.................

480sparky · 09-13-2009, 04:03 PM

Quote:

Originally Posted by mrmike

???? Lighting circuits are never across the coil of the Contactor. The lighting is across the contacts of the Contactor. The coil is usually pulled in by a relay or remote switch, etc- most times thru a Photocell. We had multiple outside area lights turned on by one contactor with just one photocell to turn them on.................

I think we said the same thing.

It's the lighting circuits that use 20 amps, not the coil. Sometimes it's the same circuit, but the coil won't use 20 amps when pulled in.

ampman · 09-15-2009, 08:08 PM

Quote:

Originally Posted by firemike

We used to use something like this in the stores we did. just a simple off-delay relay that controls the coil of the contactor.

http://www.grainger.com/Grainger/items/1EJP3

Turn the light switch off and the contactor turns the lights off after predetermined amount of time (ie. Give the employees enough time to get out of the building before all the lights went off)

this is what is needed timers will need to be reset in the event of a power outage unless they are battery backed up ,make it to complicated and "employees" will not get it