compressor different need help - http://www.hvacmechanic.com/ Forums

Original message

mint5jf

98.222.106.219

"compressor different need help" , posted Tue 3 Jun 22:18

just installed new copeland 2 ton compressor and it has two new black wires coming from the bottom of the compressor that the other one did not. what do i do with these. are they for some kind of thermal breaker or something?
thanks
also is there anything i need to know about starting up a brand new compressor? i only do new installs in complexes and have never done compressor change.

Replies:

Houston204

98.196.66.53

"Re(1):compressor different need help" , posted Tue 3 Jun 23:21

Those 2 wires are your crankcase heater. Most brands just wire them hot to 240 volts. If you have a single pole contactor, you can wire them to opposite sides of the leg broken by your contacts.
(This Carrier example has a temp control, but most carriers just use the single pole method)

Trane uses a temperature control on many of their units (Violet & Violet w/white stripe). You would wire that hot, since the temp control breaks the circuit.

Be sure your lines are free of debris from your last compressor. I recommend a suction filter with that liquid line drier. Pull a good vacuum.

If your metering device is a TXV charge by subcool. If your metering device is a piston, monitor the high side but charge by superheat.

"Tip of the Day" Remember to remove power first.

mint5jf

98.222.106.219

"Re(2):compressor different need help" , posted Thu 5 Jun 21:40

well i got it going but after about 5 minutes the compressor just kicks off. why would that do that?

mint5jf

98.222.106.219

"Re(3):compressor different need help" , posted Sat 7 Jun 02:19

ok here are my thermostat wires so i can make sure i have them right.

furnace colors-
red
white
grey
brown

thermostat wires-
green
blue
white
red

ac unit wires-
red
white

please confirm for me that i have them right by telling me which wires go where.
thanks so much