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Old 05-24-2011, 02:10 PM   #31
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Help with older A/C unit


The resistance varies from different manufacturers, BTUs/Hp of the compressor etc etc so there is no definite readings. Usually 3-5 ohms from what I remember. If it is shorted make sure NO ONE gets near it or touches it when you reset it or they will be the path to ground and DEATH. Shorted/shorting compressors sometimes run the condensor fan slowly and confuse people and can electrocute you if you touch it.

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Old 05-24-2011, 02:31 PM   #32
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Help with older A/C unit


so there may be a glimmer of hope yet...3 ohms was my lowest...here's to hope.

I'll check the resistance to ground tomorrow morning pending the weather...check back around 11 - noon ish.

I have the fuse out so there's no power and I won't be plugging them in again until something has changed to maybe fix the problem or a new unit is installed.

Thanks.
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Old 05-24-2011, 05:04 PM   #33
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Help with older A/C unit


Time to replace it locked rotor or grounded when the fuses blow that fast.
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Old 05-24-2011, 06:30 PM   #34
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Help with older A/C unit


Pete the compressor is shot if you're reading almost 1000 ohms, it should be under 5 ohms.
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Old 05-24-2011, 07:34 PM   #35
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Help with older A/C unit


Okay. Then I guess the next question would be, once we're ready to replace, do we just replace the condenser unit or the lines and evaporator as well?

The furnace is a mid-efficiency from 2002 but judging from the age of the humidifier I replaced when we moved in, I'd say the evaporator is as old as the condenser.

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Old 05-24-2011, 09:05 PM   #36
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Help with older A/C unit


Condesor and evap coil needs to be a matched set. Keeping the old evap coil will make your new 13 seer more like an 8 and reduce capacity. I'd replace the line set also
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Old 05-24-2011, 09:31 PM   #37
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Help with older A/C unit


I agree. The old evap coil will leak freon VERY soon from age. Also will not match the new condensor and even if you tried it the operating pressures will be wrong and you will lose capacity and efficiency. I replace the lines 99% of the time. 1% is the people with totally enclosed ceilings. It gets pretty humid in Southern Ontario and with a newborn I would buy a new unit sooner than later. Trying to get one in the middle of Summer or a heatwave is going to cost a LOT more and you may have to wait/suffer for weeks by the time they get to you (Momma ain't going to be happy and you know where that leads to). Try Direct Energy or Ontario Hydro/Hydro One or whatever they call themselves. They may have rebates for higher efficiency units and reasonable financing plans. $6000 high end unit over 60 months is $100/month and you can get them cheaper than that.
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Old 05-25-2011, 11:39 AM   #38
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Okay, thanks everyone. Just for ****s and giggles I checked the compressor again.

None of the lines are any where near shorted to ground. But I got similar readings for resistance between the lines (3, 903, 906 ohms). So I guess the windings are separated/corroded inside but not touching ground.

Thanks again, this has been the most helpful set of forums I've ever been on!
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Old 06-14-2011, 12:01 AM   #39
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Just an update...We got a new AC installed...it took two days of 44*C humidex temperatures for us to get a line of credit and have my cousin who is a certified installer put one in for us. Now the weather is cold again
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Old 06-14-2011, 12:09 AM   #40
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That's pretty funny.
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Old 06-15-2011, 12:12 AM   #41
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Maybe from you point of view Doc. Did you get your rooftop unit on time?
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Old 06-15-2011, 12:16 AM   #42
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Quote:
Originally Posted by pete0403 View Post
Maybe from you point of view Doc. Did you get your rooftop unit on time?
Six tons of 410-A Trane cooling/ heat pump installed today. Waiting on the electricians to give us power.

I enjoy working with cranes, always a blast.
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Old 06-15-2011, 10:20 AM   #43
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Trane is the brand I got installed as well. A little smaller though.

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