HVAC help please...

[Ted Stryker]

Fan on the condenser isn't running... I replaced capacitors in the outside unit, and it sounds like the compressor is running, just not the fan... I get 246 volts out of the contactor when I override it, but still doesn't get the fan going... The fan motor is about 2-3 year old Dayton 1/6 hp unit and it still spins freely when pushed, not locked up like the old motor that I replaced... Is there anything left to check, or is it a closed and shut case of a bad fan motor.. thanks...

[njj502]

Check the wiring for opens or shorts. Two weeks ago I came home to a 80 degree house. The inside HVAC fan was going, outside unit fan going but compressor wasn't compressing. Eneded up being a burned up wire, burned up b/c it had corroded and resistance went up resulting in burned wire. I got lucky and stripped back about 1" of crap and put two new connectors on. Are you getting a signal out of the switch?

[Ted Stryker]

I'm an Electrician, not an A/C guy so forgive me for being a little ignorant with the terminology... As far as a signal from the switch, I assume you mean the t-stat and If so then I do think I am - or at least as of 2am this morning I was when this problem reared up... In regard to checking for shorts or open wiring, I've never done it on A/c equipment and I'd have to study into that a bit to make sure I'd be doing it correctly... I took off work this morning to replace needed parts like capacitors, and or fan motors but My electrical testing tools are on my usual service truck which is who knows where at any given time running service calls so checking windings and such may have to wait for now... I'd be happy with 80 degrees, at 10 am my house was 92 degrees... Thanks for the quick reply...

[JR IN JAX]

Are you sure the fan motor has 230 volts to it? Many times on residental units, ants, spiders or other insects get into the gap of the contactor just as it closes. They are fried but the don't conduct electricity. The contactor appears closed but it is not sending both of the hot legs [230 volt] to the compressor or fan motors. If you are sure there is 230 volts going to them, check the case temperature of the fan motor and see if it is hot. If it is not hot and has 230 volts going into it then the motor's windings are burned open.
I bought a fairly nice DVOM from Walmart for $25 while on vacation so I won't have to put one of my Fluke meters in my car when we are away from home.

[Ted Stryker]

I've got the t-stat turned off now since the fan motor isn't gonna run, so I don't know if it would get hot at the moment... The 246 volts was measured on the load side of the contactor, but I haven't actually taken the top off the unit to check it at the motor itself... Would you recommend me turn everything back on to see if the motor will get hot, or will this hurt other a/c components in some way seeing as there is no fan movement to cool the coolant lines..? I'd be happy to replace the motor again, I have a Grainger about 6 miles from here so it's not a big problem... I'm just a little dumb when it come to A/C troubleshooting and didn't want to waste $90 and a few hours... Thanks for the reply....

[njj502]

If the compressor runs but no fan I wouldn't run it. The pressures will get high and trip the pressure limit switches. That's what they are there for but still it's hard on components.

By switch I meant what ever tells the fan to turn on. I'd guess it's in the outside unit. Is that the contactor you all are talking about? I'm no electrician or A/C guy, just a jack of all trades master of none... ;)

[Ted Stryker]

The contactor mentioned is the one that is in the condenser unit itself where the power comes into the unit through the seal-tite whip from the wall mounted a/c disconnect... I'm getting full power through it when the t-stat cycles...

[JR IN JAX]

Check the condenser fan motor to see if it gets hot. If the compressor is running without the fan then use a garden hose to sprinkle the coil without hitting the fan motor. If the fan has power and is not hot then the windings in it are burned open. If the fan is hot then it could just be a bad capacitor. If you put on a new fan capacitor and have the fan powered up then carefully lift the capacitor terminal off and see if you get a small spark. No spark means bad capacitor or open capacitor winding inside the fan motor. BTW you can run a hose on the condenser coil as a short/temporary measure until the motor is replaced. OEM motors are better than the Chinese Grainger/Johnstone kit motors.

[Ted Stryker]

I just checked for continuity between the two leads that power the fan motor according to the nameplate schematic, and got no continuity with my Brother's multi meter... 10-4 on the garden hose, for about the last month I have been keeping a small sprinkler on it to supplement the fan's cooling... I'll try to check for capacitor arc here shortly... Thanks again, this is a real help...

[Ted Stryker]

It was the fan motor... I put new capacitors on the motor and compressor to no avail... Went back and bought a fan motor and put on there, and she's up and stirring... Thanks for all the help Guys, I do appreciate it...