| current draw vintage roof air [message #219000] |
Sun, 18 August 2013 20:34  |
hertfordnc
Messages: 1164
Registered: September 2009
Location: East NC
Karma: 0
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Just acquired another old camper (it's a sickness)
Came with large roof air, very old. It worked well for a while before popping the 20 amp house breaker.
I think a modern high efficiency 13K btu only draws 12 amps right?
Does it make sense that a much older one might draw 20?
Not practical to drive it to the nearest campground an plug it in.
When it worked it was perfect, very cool and very quiet.
thanks
Dave & Ellen Silva
Hertford, NC
76 Birchaven, 1-ton and other stuff
Currently planning the Great american Road Trip Summer 2021
It's gonna take a lot of Adderall to get this thing right.
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| Re: current draw vintage roof air [message #219006 is a reply to message #219000] |
Sun, 18 August 2013 20:43  |
Hal StClair
Messages: 971
Registered: March 2013
Location: Rio Rancho NM
Karma: -12
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If you are running on an extension cord your voltage drop might trip your breaker. As the voltage goes down, the amps will rise causing the problem.
Hal
"I enjoy talking to you. Your mind appeals to me. It resembles my own mind, except you happen to be insane."
1977 Royale 101348,
1977 Royale 101586, Diesel powered,
1974 Eagle Bus 45',w/slideout,
Rio Rancho, NM
[Updated on: Sun, 18 August 2013 20:44] Report message to a moderator |
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| Re: current draw vintage roof air [message #219011 is a reply to message #219000] |
Sun, 18 August 2013 21:08 |
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Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
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| hertfordnc wrote on Sun, 18 August 2013 21:34 |
Just acquired another old camper (it's a sickness)
Came with large roof air, very old. It worked well for a while before popping the 20 amp house breaker.
I think a modern high efficiency 13K btu only draws 12 amps right?
Does it make sense that a much older one might draw 20?
Not practical to drive it to the nearest campground an plug it in.
When it worked it was perfect, very cool and very quiet.
thanks
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Dave,
Where that I could give you a better answer, but the truth is that I never cared enough to get out a meter for the new unit.
What I do know is that the 13.5K Coleman MarkV that I took off drew every bit of 15 amps running and that was a '95 vintage. The Carrier 15K I have now does not draw as much, but I never measured.
It would surprise me if the vintage 13K drew more than 15 amps running because that would take uncommon circuits to support that load.
A good thing would be to go and buy a "Kill-A-Watt" (~25$) and get real answers. Silly guy that I am, I carry one because they are the best thing to adjust your Onan.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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| Re: current draw vintage roof air [message #219018 is a reply to message #219000] |
Sun, 18 August 2013 21:30 |
roy1
Messages: 2126
Registered: July 2004
Location: Minden nevada
Karma: 6
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How much older then a72 Revcon can it be? The voltage at the a/c needs to be within 10 percent of the rated voltage in other words approximately 105 volts or more less can cause the breaker to trip if you are using a long run from a 20 amp supply or as Hal suggested a light extension cord you may have low voltage at the a/c unit. The older piston compressors take a little more to get going then the newer rotary ones
Roy Keen
Minden,NV
76 X Glenbrook
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| Re: current draw vintage roof air [message #223385 is a reply to message #219018] |
Sun, 22 September 2013 19:40 |
Chris Tyler
Messages: 458
Registered: September 2013
Location: Odessa FL
Karma: 7
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If its a old piston type duotherm, yes, they pull a lot of amps when you start them. Not so bad once running, and they would cool better than the coleman 13.5s back in the day. I found they would often trip the breakers on startup. It helped to start the fan first and let it run a few min first, then put it on low and kick the cooling in. I seem to remember there was an upgrade to a higher farad start capaciter...but its been ~25 yrs since I was a service tech.
Those were some durable units though!
76 Glenbrook
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| Re: current draw vintage roof air [message #223388 is a reply to message #223385] |
Sun, 22 September 2013 20:05 |
roy1
Messages: 2126
Registered: July 2004
Location: Minden nevada
Karma: 6
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| Chris Tyler wrote on Sun, 22 September 2013 17:40 |
If its a old piston type duotherm, yes, they pull a lot of amps when you start them. Not so bad once running, and they would cool better than the coleman 13.5s back in the day. I found they would often trip the breakers on startup. It helped to start the fan first and let it run a few min first, then put it on low and kick the cooling in. I seem to remember there was an upgrade to a higher farad start capaciter...but its been ~25 yrs since I was a service tech.
Those were some durable units though!
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Generaly the best size microfarad start capacitor to get the compressor up and running was the size the compressor manufacturer said too use and that goes for the start relay also.
Roy Keen
Minden,NV
76 X Glenbrook
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