House AC woes [message #282449] |
Sun, 19 July 2015 08:00 |
jhbridges
Messages: 8412 Registered: May 2011 Location: Braselton ga
Karma: -74
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I had Frady install a new Dometic heat pump a couple years ago. I've been pleased with it up till yesterday. I turned the breaker on and the fan came om. Switch is on the OFF position. Turned it to COOOL and cold air comes out for a few minutes then the fan stops, compressor still running. Turn the switch to OFF and everything stopped. A few minutes later, the fan started up. So I killed the breaker and considered. For some reason, the fan has 110 supplied to one of its windings. When the 110 is applied elsewhere, there's a problem and the motor overheats and trips out. Today's project - take the inside [panel off, check the switch, and chase the fan motor wiring with my meter. Either there's a control problem or the motor has a grounded winding.
--johnny
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
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Re: House AC woes [message #282454 is a reply to message #282449] |
Sun, 19 July 2015 09:51 |
jhbridges
Messages: 8412 Registered: May 2011 Location: Braselton ga
Karma: -74
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Senior Member |
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Well, anything's possible. I haven't pulled my schematics yet...
thanks,
Johnny
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
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Re: House AC woes [message #282455 is a reply to message #282449] |
Sun, 19 July 2015 10:13 |
Ken Burton
Messages: 10030 Registered: January 2004 Location: Hebron, Indiana
Karma: 10
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Senior Member |
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Lubricate the fan motor shaft. It is just a guess.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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Re: House AC woes [message #282458 is a reply to message #282455] |
Sun, 19 July 2015 11:45 |
roy1
Messages: 2126 Registered: July 2004 Location: Minden nevada
Karma: 6
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Senior Member |
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Check fan electrical connections and fan run capacitor
Roy Keen
Minden,NV
76 X Glenbrook
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Re: House AC woes [message #282468 is a reply to message #282449] |
Sun, 19 July 2015 13:19 |
jhbridges
Messages: 8412 Registered: May 2011 Location: Braselton ga
Karma: -74
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Senior Member |
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Wello.... fan motor is fine - turns free. Both caps and the compressor start bimetal are fine. So I pulled the inside housing off and opened the switch box. The speed/function selector switch has achieved Condition FUBAR.It got so hot it melted the low speed fan wire to the hot wire. Thus, when power was on the coach, low speed fan. Turn it on and set any other speed, the low speed winding is shorted, overheats it and trips the thermal breaker. So I go on the net looking. The nice chat ladt at a parts house volunteers, the switch is discontinued (not surprising) and there is no replacement listed. I can fix it with a couple of bat-handled toggle switches if I can't find a three speed replacement with heat rotary at the parts place. 1 DPDT for compressor and heat pump valve, two DPDT for the three fan speeds:
FAN LO->
FAN>MED_HI
COOL-HEAT
Or I can fly on two and skip the medium fan, lo and hi only.
Here's a look at what I found:
http://www.gmcmhphotos.com/photos/g6825-dometic-heat-pump.html
I suspect when the tab melted off the metal cover, the end of the plastic box loosened and rwemoved the pressure on the contacts. When they loosened, they arced and burned, this is the result.
--johnny
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
[Updated on: Sun, 19 July 2015 13:39] Report message to a moderator
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Re: House AC woes [message #282615 is a reply to message #282449] |
Mon, 20 July 2015 12:30 |
jhbridges
Messages: 8412 Registered: May 2011 Location: Braselton ga
Karma: -74
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Senior Member |
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So, I go looking for the switch. Dyer's RV has a substitute - not stock - for only 50 scoots plus 35 to Dometic to drop ship it. Adventure RV has the McCoy - for only 110 bux plus shipping. Dyer has the electrically identical (read off the side of both switches) for $13, the mount is different. Well, the original has an add-on shaft extension anyway, and the reviews for the 13 dollar one say 'you have to mount it, but it works.' So for 90 dollars less after shipping, I'll make a mount. Keep watching this space.
--johnny
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
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