Does it matter which which wire goes to the A/C Contactor?

[mpire]

I got a quick question.

With my 4 ton Carrier A/C unit, the outside compressor has a contactor that fires up the unit when the signal wire tells it to turn on.

I know its 220 power, so there are two phases going to the contactor.

I don't see any reason that it would make any difference which phase goes on what side of the contactor, but I figured I would ask.

Essentially I am asking if it matters which way the wires are connected.

 

[dave67fd]

I don't see any reason that it would make any difference which phase goes on what side of the contactor

Neither do i.

 

[HVAC Phil]

No it doesn't. Most contactors out there, one leg is always hot, with the other leg being broken by the contactor.

 

[mpire]

I couldn't figure out why it wasn't starting up so I figured I would ask.

I swapped the wires and it fired off after a few minutes.

Does the fan kick on when the compressor starts, or does it just come on when its needed?

The contactor is less than a year old, it was replaced last year, so I was hoping it wasn't bad.

Wife retreated to the bedroom while I checked everything out. That mini-split was a brilliant purchase!

 

[HVAC Phil]

Being it is a carrier, it may bit a bit "over controlled". Most likely there is a timedelay on the low voltage. Also, the cond fan may have a pressure delay as well, runs as headpressure builds. Is there a circuit board?

 

[mpire]

I guess there is a circuit board. Its standard stuff. I also have backups I got from the neighbors unit when their compressor died.

I replaced the pull out disconnect and the conduit from the wall with new stuff, and it didn't start back up when I powered it up.

Then I swapped the leads and it fired up.

So IDK, I was just curious if swapping them made any difference, or if it was a delayed start.

Usually it starts right up when I hear the thermostat click on.