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Carrier split system heat pump


I have a 3 ton Carrier split system heat pump.  The condenser fan motor bearing locked
down.  I replaced the motor.  The old motor was an OEM 3 wire motor. I replaced with a
universal 4 wire motor.  Installed a 5 mfd cap.  Removed the wires from the duel cap on
the motor. ran my blk wire to the defrost board. ran my yellow wire to the contactor.
brown and brwn/wht wire to the new 5/440 cap.

Started the unit. verified proper rotation. Unit ran for about 10 seconds. contactor disengauged
Defrost board took it out.  no 24 volts present at the contactor.  I checked my low voltage wires
I have 24 volts across yellow and common going to the defrost board.  Board kept the unit off
for about 5 minutes. Then, click the 24 volts was restored to the contactor for about 10 seconds- then off again for 5 minutes.

I disconnected power leads to the compressor .  Restarted  condenser fan motor came on and stayed on.  Reattached compressor wires- restarted  compressor pulled 8 amps.
RLA on compressor is 18 amps.
Checked pressures- compressor is running   I did not see a low pressure switch. didnn't look that close either.

any ideas

Sounds like a low pressure lockout to me.

 ???  If the RLA is 18 and you only read 8 on start-up makes no sense. Starting Amp's are 5 times the running amps. :)


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