DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (
-   HVAC (
-   -   Need help replacing HVAC condensor fan motor - 3 wire old to 4 wire new (

jmcinni 08-18-2012 10:56 AM

Need help replacing HVAC condensor fan motor - 3 wire old to 4 wire new
I'm replacing my old three wire condensor fan motor with a new four wire fan motor. The capacitor is a dual run cap with three terminals. The old wires were red (goes straight to T2 on the contactor), brown/white (goes to cap), and black (goes to fan terminal on a circuit board which I think is the defrost relay). There's a terminal on that same board marked "cond" right next to the fan terminal, and that terminal is wired with a black wire to T1 on the contactor, so I'm thinking this is just a connection bridge for the fan to T1 where it hits the relay first.

On the new motor, it has brown and brown/white, which both go to the cap, and two line wires, white and black. I believe the white wire would correspond to the red wire on my old motor and the black to the black.

My question is, to get the CW rotation I need on the fan, the new motor says to switch the white and black wires. Since the black wire on my old motor goes to the circuit board first rather than to the T1 on the contactor, is this going to cause a problem for me?

hvactech126 08-18-2012 02:37 PM

to change the rotation there is often a small wiring connector that comes just off the motor that you can turn around it it will reverse the direction. switching the 240V leads will do you no good on a psc motor.

jmcinni 08-18-2012 02:55 PM

thanks for the help, I found that connector and switched it. I ended up just capping off the brown/white with a wire cap and then wiring into the existing 3-wire plug with crimp connectors going brown to brown, white to red and black to black. Fan's working great and the AC works again :thumbsup:

hvactech126 08-18-2012 03:07 PM

I hope that you replaced the capacitor as well. And that the capacitor is the correct value as needed for the replacement motor.

jmcinni 08-18-2012 04:11 PM

yes, replaced that as well.

All times are GMT -5. The time now is 01:13 AM.

User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2015 DragonByte Technologies Ltd.