220V relay question
#1
08-06-09, 09:38 PM
220V relay question
I'm trying to wire a thermostat relay (24V coil) to control a 220V A/C unit. The whole unit runs off of two 'hot' wires, one black, one white (supposed to be black). My question is: what kind of relay (SPDT, DPST, DPDT, etc) do I need? I think I will need a DPDT, dual pole dual throw relay. If so, which wires go where?
#2
08-07-09, 04:33 AM
Member
You would just need to get something like this Dayton 2UTL4 Definite Purpose Contactor with a 24 volt coil. You can get one like this or a 2 pole.
Your line leads would just terminate on the top 2 poles and load out of the bottom. Of course your 24 volts would terminate on the coil.
It would also need to be in some sort of enclosure.
Your line leads would just terminate on the top 2 poles and load out of the bottom. Of course your 24 volts would terminate on the coil.
It would also need to be in some sort of enclosure.
#3
08-07-09, 11:18 AM
Thanks a lot, I definitely need a definite purpose contactor like you said; smaller DPDT relays won't handle the amperage I'm needing. Another question, though: when I was trying to wire it to a smaller relay, sometimes the breaker would throw, sort of. It wouldn't go all the way to the "on" position. I would change up my wiring, re-throw it, and it would be fine. What does it mean when a breaker is doing this?
#5
08-08-09, 09:35 PM
Yep, that was it. I had it wired with a single-pole switch, and one way I had it, it must have been connecting black (120V positive) to white (120V negative), throwing the breaker. Thanks a lot. Let me just be sure, 2 pole contactor, 220V: black and white line in the top, black and white load out the bottom, 24V lines wired to the coil, no thrown breaker, correct?
#6
08-09-09, 06:01 AM
Member
Sounds like you got it licked. Be sure to re-identify those white wires as ungrounded (tape with black/red tape or similar except green)Beer 4U2
