nordyne hard start outdoor unit

Questions about repairs and parts for Nordyne furnaces, air conditioners and heat pumps for manufactured homes including Intertherm, Mac and Miller brands. Click here for Nordyne parts.

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ricksch
Posts: 9
Joined: Wed Jul 29, 2009 9:24 am

The original contactor decided to quit on friday so the whole weekend I was turning the outdoor unit on and off with the breaker. I got a new contactor from a local place but they shipped a fla30 amp res 40 amp dual pole 240v 24v coil contactor. The contactor out of the unit was a fla25 amp res30. I installed the contactor yesterday morning and the unit ran great. Last night the outdoor unit started only humming and the condenser fan motor would run real slow. This morning I got a new capacitor and installed and the unit ran fine till about 1/2 hour ago it would start doing the humming and the fan is turning real slow again. Is it possible the higher voltage contactor is affecting the capacitor?
Thanks for your help
Rick
model# T2QC-036k
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Robert
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Posts: 6413
Joined: Wed Feb 28, 2007 12:07 am
Location: Tennessee

Hi Rick,


That's not higher voltage, it's higher amps and volt-amps that the contactor can handle.


It will handle what your old one did and then some, they must be same or higher rating.


It is fine. Did you replace run capacitor with same mfd and same volts rating ?


If so, then you need to check voltage to motor and if it is 240vac, motor is bad.



Thanks,
Robert
Some people are Humbly Grateful, while some are Grumbly Hateful.................... Which one are you ?
ricksch
Posts: 9
Joined: Wed Jul 29, 2009 9:24 am

Thanks Robert.
I ment amps not volt.oops.
I took the capacitor off and matched one up at a store that sells nordyne parts.
I checked to see if the fan spins freely it does so it's not bound up.
I was standing outside when the unit was turned on and all it did was humm then after alittle time there was that buzz sound when the outside unit starts running and it started up. I'll do some volt meter tests tomorrow morning.
I really can't afford a repair man right now, laid off, money's running low, bills due, great economy right now????

Thanks
Rick
ricksch
Posts: 9
Joined: Wed Jul 29, 2009 9:24 am

I just went and turned the thermostate on and temp down to start the A/C and the outside unit just humms and the fan doesn't turn and no sound from the indoor unit of the freon going through the system.
A capacitor only cost $5.00 I'll put another one on and go from there.
Rick
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Robert
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Joined: Wed Feb 28, 2007 12:07 am
Location: Tennessee

Hi Rick,


IF nothing is working outside, no compressor or fan motor, then check to see if contactor bar is pulled all the way in with call for cooling.


IF so, should have 240vac coming into contactor top or bottom.


240vac going out the other end.



Tow small wires, one to each side should read 24vac across them and one should read 24vac to ground, other should read 0vac to ground.



IF not pulled in, use insulated handle tool and push it in to see if compressor and fan will run.



Thanks,
Rick
Some people are Humbly Grateful, while some are Grumbly Hateful.................... Which one are you ?
ricksch
Posts: 9
Joined: Wed Jul 29, 2009 9:24 am

I put on a new capacitor and hooked up volt meter. I have 240 at the bottom and when I push in the contact the top reads 244 and everything starts. Went in and turned on the thermostat and all I had was that vibrating humm sound then all of a sudden the unit started. I let it run to cool the house down. The unit shut down but wouldn't restart. I took the cover off and hooked up the volt meter and had my daughter turn the thermostat on while I watched and the contactor is not engaging infact you can see the contact vibrating in and out. I hooked up volt meter and got 3.3 volts when the contact was vibrating and when it engaged and the unit started it read 25.2 volts and the unit is running now. going to put the old contactor on after I do some touch up work on the contacts and see what happens.

Thanks Again It's Appreciated
Rick
ricksch
Posts: 9
Joined: Wed Jul 29, 2009 9:24 am

did another test on the new contactor and got 15.3 volts across the 2 wires, contactor wouldn't engage till I pushed it in.

Edit:
I cleaned up the contacts on the old contactor and reinstalled it and the outside unit starts right up.

Rick
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Robert
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Posts: 6413
Joined: Wed Feb 28, 2007 12:07 am
Location: Tennessee

Hi Rick,

That great. The new contactor is fine for your unit, but could be bad, it does happen.


The way the unit kept changing how and when it ran and the readings, could be something amiss in the wiring also.


Send and/or carry contactor back and have it tested to see if it is bad or not.


IF it is good, better keep testing to find source of problem.


You're very welcome, happy to help.


Thanks,
Robert
Some people are Humbly Grateful, while some are Grumbly Hateful.................... Which one are you ?
ricksch
Posts: 9
Joined: Wed Jul 29, 2009 9:24 am

I ordered a new 621661 contactor from you guys.
Does a transformer control the voltage to the thermostat? Is it in the indoor unit?

Thanks
Rick
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Robert
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Joined: Wed Feb 28, 2007 12:07 am
Location: Tennessee

Yes and yes, it is inside the control box.


You can turn t-stat off, remove cover(s) to reveal wiring and test across R and Y for 24vac to see if transformer is working.



OR, set t-stat to OFF and Fan to On. IF blower runs, transformer is fine.



Thanks,
Robert
Some people are Humbly Grateful, while some are Grumbly Hateful.................... Which one are you ?
ricksch
Posts: 9
Joined: Wed Jul 29, 2009 9:24 am

Hi Robert,
I got the new contactor this morning, I installed it and had my daughter start the AC while I watched the outside unit. The contact bar litteraly vibrated back and forth and burnt up, disintigrated.
I did the test from your last response and have 24v in the indoor unit and outside at the AC. I put the old contactor back on and started the unit with a volt meter on the terminals for the coil and got 9 volts the contactor vibrated back and forth again till the voltage went up to 15v and the contact engaged. I let the unit run then shut the stat down and waited and restarted the unit and got 16.5 v at start up then went up to 24 volts. Shut the stat down again and tried a restart with the indoor fan running(thinking that might be putting a big draw) the contact vibrated back and forth till the voltage went up to 16.7 volts but stayed there this time. Something in the defrost control board went bad???

Thanks
Rick

EDIT: AUG 25
In talking to a friends friend last night it was suggested that I might have a bad connection or bad wire(animal under house). I get 24v withno draw but when I put a draw on the system the volts go down. I was also told to check the Y and C terminals on the defrost board outside, the wires from the board to contactor come from posts T1 and C. The problem could be in the stat and to run a jumper wire between the red and yellow terminals.

EDIT: AUG 25 2:30pm
I tried to pay for technical help with paypal but it wants to charge $8.00 for shipping.

I cut back all the wires and reconnected, checked the wiring under the house. I turned the system on and had 24+volts at the R/Y and the R/C board terminals at the outdoor unit. I told my daughter to turn the stat down to start the AC and I had 6-9 volts at the contactor coil, and it chattered big time but started and 24+ at the C/Y terminals. It started ran with 9 volts at the coil and 24+V at the R/C and C/Y terminals and 9V at the T2/C terminals for the coil wires, where the 2 wires for the coil plug into the board I get 9+volts and 24+ at the C/Y terminals. After it ran for about 3 minutes the voltage at the coil went up to 16+ volts after about 10 minutes it's up to 24+ at the coil. I shut the AC off and restarted and the volts at the C/Y stat terminals on the board spiked to 31-33 the AC started and the voltage went down to 24+ and 9+ at the coil wires.

Rick
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Robert
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Posts: 6413
Joined: Wed Feb 28, 2007 12:07 am
Location: Tennessee

Hi Rick,


Just got this, sorry about the PayPal hiccup, been happening for a while now, Mark needs to look at it.


You can call toll free to do it if still needed to 1-877-263-7860.


Headed back out, will check out what you posted in depth tonight.



Thanks,
Robert
Some people are Humbly Grateful, while some are Grumbly Hateful.................... Which one are you ?
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