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Can this run cap for a furnace be tested?

LHorn

LHorn

AK Subscriber
Subscriber
My A/C died yesterday. It was working fine around noon then about 6pm I heard the compressor running but the blower motor wasnt kicking on. When I listened to it the motor was just pulsing on and off. If I turned the cooling off and then turned the fan switch to manual it still just pulsed...then eventually did nothing. Blower cage turns fine no noise. New batteries in thermostat. Jumping the fan at the thermostat produces nothing also.

I have a cap tester and a multimeter...can I test this like a regular speaker cap?

Time is of the essence...it's in the 90's here this week. Thanks

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Yes. That is a start cap, and if it reads considerably more than 5u, it is bad and needs replaced. HD or Lowes should carry them, just make sure it's the same value (and internally protected).
 
OK...now I have to find it. I thought it would be on the main board but its not.

This is the main board...

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I dont see it anywhere. Unless it behind that board. Only thing at the motor is two plugs from the harness.

I rent and the guy they sent out said it was an internal cap in the motor that cant be replaced. But when I searched the model number of this unit it definitely shows the cap, board and the motor which is $900. I was hoping I could just pull the cap and check it easily but I guess not. I dont want to tear anything down. The owners did send him the pic of the cap I sent them...so I guess he'll have to figure it out.
 
A motor repair shop near me, stopped in to have a motor fixed and he tested the cap. For this 240V motor (cap rated higher) he filled it 120V across the cap and then spark tested it with a screwdriver. No spark dead cap, nice healthy spark took a nibble out of the screwdriver used to short the cap.
 
Blue Shadow said:
A motor repair shop near me, stopped in to have a motor fixed and he tested the cap. For this 240V motor (cap rated higher) he filled it 120V across the cap and then spark tested it with a screwdriver. No spark dead cap, nice healthy spark took a nibble out of the screwdriver used to short the cap.
Click to expand...

Yep...I'm aware of what they can do to ones bodily functions...but I cant even find it. Maybe the parts place I looked at is wrong even though the other parts are correct. :dunno:
 
highvoltage_ said:
Look where the wiring from the house comes into the unit. It should be near there.
Click to expand...

This is the blower in the house not outside if thats what you mean. The thermostat wires go to the board above. All the black and blue boxes on the board are relays. The normal canister run/start caps I'm familiar with...this setup is strange. It's freakin' 86° in my house right now! :rant: I can deal during the day but I cant sleep like this...even with a fan blasting on me. I got 3 hours last night because it was storming and I couldnt open the house up to cool it down. SMH

This is the model # in case anyone is bored...

Carrier model 59sp5a080e17--16

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Landlord is responsible for repair. How long he has to get it done?
Takes too long, you may have to get a window mount AC ($300??) in bedroom.
 
Although I'm not an HVAC tech, I have serviced many bio safety and laminar flow hoods (with blower motors just like yours) and have never come across one where the cap was internal to the motor.

The majority of the time, the problem was the start cap. Yours is located in the small metal box (with the 3 wires coming out) directly above the board. To access it, you first need to remove a couple of bolts/screws on the underside of the rails (although, yours may be secured differently). The entire unit will then slide out on those rails.

Any HVAC/motor repair shop should have it in stock. Grainger also carries a good supply, if you're near one.

Edit: There's a word (or perhaps many) for those who want to charge $900 for a $10 part. :mad:
 
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The blower motor is on tracks and will slide out. You might have to remove a couple screws. Usually the start/run caps are mounted on the side of the blower housing. Assuming that's what we are searching for
 
SolderIron said:
Landlord is responsible for repair. How long he has to get it done?
Takes too long, you may have to get a window mount AC ($300??) in bedroom.
Click to expand...

Yes they are but they hired this young guy that in watching him seemed to me like he was guessing his way through this. $300 not an option for a fixed income.

@rickb119 ..The first pic is the one on top. I know it looks like a metal cover in the crappy pic but its similar to the bottom right component. Its wires go to the board.

Second pic is what the manual calls a Capacitor Power Choke. It is the only thing wired to the motor (with two heavy black wires) other than the harness from the board. Could this be it? Could the black part I first posted about be under the white cap of this?

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Heres a description that may help although mine is not a heat pump...gas heat and AC unit...

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Here's a more detailed explanation. https://www.motioncontroltips.com/what-is-a-motor-choke-and-why-is-it-used/

The units I worked on were all standard motors, and not the type described in the article. Therefore, the tech could be right about the cap being in the motor (since it's not visible anywhere else). I think the plastic cover is just that; a cover for the wire connections.

I think you're stuck with waiting for the tech to come back (with, hopefully, the right parts).

I too can't sleep if the temp is too high. I feel for you. :hug:

The good new is, it's not coming out of your pocket.
 
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