Picking the correct A/C contactor
#1
05-02-17, 12:07 AM
Picking the correct A/C contactor
Our contactor seems to be getting stuck every couple days (compressor keeps running even though the A/C is off). Flipping the breaker (or even a slight bump to the side of the unit) dislodges it and it works again for a few more days. Anyways, I assume that I need a new contactor, but I can't figure out the amperage that I need (I believe it is single-pole). The breaker is 60 amp, but 60 amp contactors don't seem to exist and that seems too high. I am attaching pictures of the A/C info and the contactor itself. Any help would be greatly appreciated!!
Thanks,
Ryan
Thanks,
Ryan
#2
05-02-17, 12:25 AM
Member
Your label indicates that the RLA (Rated Load Amps) is 10, so either a 20 or 30 amp contactor should work just fine.
#3
05-02-17, 11:48 AM
Thanks! Is it strange that the breaker is 60 amp? Am I correct that it is single pole and is there anything else I need to look for? Would something like this work: https://www.amazon.com/Carrier-Repla...+amp+contactor
Thanks again!
Ryan
Thanks again!
Ryan
#4
05-02-17, 12:40 PM
Ryan, the contactor your looking at would work fine. Contactors are pretty generic, so any 30- amp contactor would work.
Last edited by skaggsje; 05-02-17 at 12:41 PM. Reason: correction
#5
05-02-17, 06:32 PM
Super Moderator
That 60 amp breaker is wrong and should be replaced.
You need to base the ampacity of the breaker on the running amperage of the unit.
The recommendation of a maximum 20 amp breaker by the manufacturer is to ensure if the compressor fails to start it will trip before seriously damaging the compressor motor.
You also need to replace the burnt wiring along with the contactor.
With that 60 amp breaker those wires are likely glowing when the a/c is running!
You need to base the ampacity of the breaker on the running amperage of the unit.
The recommendation of a maximum 20 amp breaker by the manufacturer is to ensure if the compressor fails to start it will trip before seriously damaging the compressor motor.
You also need to replace the burnt wiring along with the contactor.
With that 60 amp breaker those wires are likely glowing when the a/c is running!
#6
05-02-17, 08:51 PM
Group Moderator
I'm guessing the 60A breaker is in the main panel. There should be some type of disconnect right at the condensor. It may use fuses that are lower in amperage.
Check for fuses in the disconnect.
Check for fuses in the disconnect.
#7
05-05-17, 01:09 AM
Thanks for the info!
There is another box outside the condenser, but the amps aren't listed on it. What type of wires would be needed to replace the ones in the picture?
Thanks again!
Ryan
There is another box outside the condenser, but the amps aren't listed on it. What type of wires would be needed to replace the ones in the picture?
Thanks again!
Ryan
#8
05-05-17, 10:29 AM
Group Moderator
Are you referring to the wires that go from the contactor to the disconnect ?
That looks like #10 THWN wire.
Did you check inside the disconnect for fuses ?
You may to pull the handle out to see behind the cartridge.
That looks like #10 THWN wire.
Did you check inside the disconnect for fuses ?
You may to pull the handle out to see behind the cartridge.
#10
05-05-17, 01:58 PM
Group Moderator
