| Original DuoTherm hot wire procedure [message #259645] |
Thu, 21 August 2014 18:12  |
Tilerpep
Messages: 404
Registered: June 2013
Location: Raleigh, NC
Karma: 7
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I posted in another thread I started my beach vacation with two original roof airs working well. Day 6 saw the 13.5 unit fan stop running, and Day 8 the 11K unit fan would run, but when it tried to start the compressor, just a stuck electric sound. Climbed up today. Good news on the bigger unit - a big, old, wasp nest had broken loose and jammed the outside fan against the housing. Rear air had no obvious issues like that. I pulled the electrical box covers to see if anything corroded and it looked pretty good actually.
Page 28-6 of the parts book showed me what was what, and I found the diagnosis run through on 24E-6 in maintenance book. So some clarification would help from you all...
The first remedy for a non-starting compressor is "add an extra start capacitor" momentarily. Since my front unit seems to use the same guts, can I wire the front into the rear? Am I putting this in series or parallel (I am thinking like wiring in car speakers, where ohms half and stay the same type thing here) to test this? Series seems easy with push on connectors. [Should I just swap from the other unit, rather than the hot wire combo deal as a first step?]
More info that might help: I turn fan on, fan runs fine. I turn it to "cool" and fan turns fine, two or so delay minutes pass and the big click of the relay is heard, but compressor does not get rolling.
The big unit compressor has wiring connections on top, easy to get to. The 11K compressor connections look down low, inside.
Extra thoughts are always welcome.
1975 Glenbrook, 1978 Royale rear bath
Raleigh, NC
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| Re: Original DuoTherm hot wire procedure [message #259664 is a reply to message #259645] |
Thu, 21 August 2014 20:00  |
Tilerpep
Messages: 404
Registered: June 2013
Location: Raleigh, NC
Karma: 7
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Senior Member |
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So, I didn't do the double "start" capacitor to try and restart the 11K unit, but I did switch first the "start" capacitor with the larger one from the 13.5 and it wumpwumpwumped like it was trying. So I added the "run" capacitor from the 13.5, and it ran noisily on startup (which was normal from my experience) and started cooling just fine.
Therefore, my compressor seems good, and I wonder if anyone would be willing to send me some capacitors from an otherwise failed unit? Ideally off a 11K unit, but it seems the larger 13.5 ones work. I did not let it run more than a minute to test, waiting to see if anyone who knows what's up cautions against the larger capacitors on the 11K unit.
Or, if someone understands all the ratings and capacities could link me to a source for new ones.
Now that I re-read this post, I wonder if the noisy fan startup is because that third "fan" capacitor is also weak or bad?
Thanks
1975 Glenbrook, 1978 Royale rear bath
Raleigh, NC
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| Re: Original DuoTherm hot wire procedure [message #259666 is a reply to message #259645] |
Thu, 21 August 2014 20:06 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Senior Member |
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I would remove, spray and reseat all the flag terminals to be sure of a solid connection and break the oxide. What you are refering to is a "hard start kit" a booster cap hoping to jar start a long idle compressor. Works sometimes. If the cap is OK an the unit won't start you have bigger problems. Yes I would swap caps to see if the known good solves the problem for you. FYI caps add in parallel and do the product over the sum thing in series (opposite of resistors) I would first do some power disconnected Ohm meter comparisons. Disconnect the compressor leads and Ohm from each lead to case. From what I know if there is continuity there then you have a shorted to case compressor winding and stop there, it's fried, but comfirm this on the good one to be sure it has no continuity to case. Also my bigger DuoTherm has the delay relay and the smaller rear one does not. I guess that was so that if power came back on you would be less likely to try to start both at the same time. Those turbine oil spout oilers work great on the fan motor bearings.
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: Original DuoTherm hot wire procedure [message #259668 is a reply to message #259664] |
Thu, 21 August 2014 20:16 |
A Hamilto
Messages: 4508
Registered: April 2011
Karma: 39
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Senior Member |
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Tilerpep wrote on Thu, 21 August 2014 20:00So, I didn't do the double "start" capacitor to try and restart the 11K unit, but I did switch first the "start" capacitor with the larger one from the 13.5 and it wumpwumpwumped like it was trying. So I added the "run" capacitor from the 13.5, and it ran noisily on startup (which was normal from my experience) and started cooling just fine.
Therefore, my compressor seems good, and I wonder if anyone would be willing to send me some capacitors from an otherwise failed unit? Ideally off a 11K unit, but it seems the larger 13.5 ones work. I did not let it run more than a minute to test, waiting to see if anyone who knows what's up cautions against the larger capacitors on the 11K unit.
Or, if someone understands all the ratings and capacities could link me to a source for new ones.
Now that I re-read this post, I wonder if the noisy fan startup is because that third "fan" capacitor is also weak or bad?
Thanks Are there any letters or numbers on the original capacitors? My brother needed a capacitor for his air compressor motor and there was enough identifying info on the old one to do an internet search for a replacement.
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| Re: [GMCnet] Original DuoTherm hot wire procedure [message #259684 is a reply to message #259664] |
Thu, 21 August 2014 21:16 |
bdub
Messages: 1578
Registered: February 2004
Location: Central Texas
Karma: 5
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Most electrical supply houses will have what you need for less than $15 or
so. Just take the old with you or at least the #.
bdub
On Aug 21, 2014 8:01 PM, "Tyler" wrote:
>
> So, I didn't do the double "start" capacitor to try and restart the 11K
unit, but I did switch first the "start" capacitor with the larger one from
the 13.5 and it wumpwumpwumped like it was trying. So I added the "run"
capacitor from the 13.5, and it ran noisily on startup (which was normal
from my experience) and started cooling just fine.
>
> Therefore, my compressor seems good, and I wonder if anyone would be
willing to send me some capacitors from an otherwise failed unit? Ideally
off a 11K unit, but it seems the larger 13.5 ones work. I did not let it
run more than a minute to test, waiting to see if anyone who knows what's
up cautions against the larger capacitors on the 11K unit.
>
Or, if someone understands all the ratings and capacities could link me to
a source for new ones.
>
> Now that I re-read this post, I wonder if the noisy fan startup is
because that third "fan" capacitor is also weak or bad?
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bdub
'76 Palm Beach/Central Texas
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