roof ac

[wayne lawrence]

My original roof ac draws so much current (shore power) it will melt the
motorhome to shore power line adapter. I tried the fan only on all 3 speeds
for 10 min each and no problem. Then I turned the ac on lowest setting for 5 min and the adaprer prongs were too hot to touch.

Is there a quick cheep fix or am I wasting my time?
--
Wayne Lawrence
76 Birchaven
Bellflower CA
w.lawrence

 

[Larry Davick]

I bought an Atwood unit from Jim K just before parking the coach for 4 years!! It’s supposed to draw like a 13.5 k BTU unit while pumping out 15k worth of cold. The few times we used it it was great.

In a separate thread I saw a link for the Amish fridge repair folks who also have refurbished ac units.

Larry Davick
A Mystery Machine

>
> My original roof ac draws so much current (shore power) it will melt the
> motorhome to shore power line adapter. I tried the fan only on all 3 speeds
> for 10 min each and no problem. Then I turned the ac on lowest setting for 5 min and the adaprer prongs were too hot to touch.
>
> Is there a quick cheep fix or am I wasting my time?
> --
> Wayne Lawrence
> 76 Birchaven
> Bellflower CA
> w.lawrence
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

 

[jim kanomata1]

You must have firm plug contact.
Loose contact will melt the plugs.
Look at the legs and see if it is made of two piece, if so spread it so it
will make solid contact.

On Thu, Aug 29, 2019 at 8:56 PM Larry Davick via Gmclist <

> I bought an Atwood unit from Jim K just before parking the coach for 4
> years!! It’s supposed to draw like a 13.5 k BTU unit while pumping out 15k
> worth of cold. The few times we used it it was great.
>
> In a separate thread I saw a link for the Amish fridge repair folks who
> also have refurbished ac units.
>
> Larry Davick
> A Mystery Machine
>
> > On Aug 29, 2019, at 8:42 PM, Wayne Lawrence via Gmclist <

> >
> > My original roof ac draws so much current (shore power) it will melt the
> > motorhome to shore power line adapter. I tried the fan only on all 3
> speeds
> > for 10 min each and no problem. Then I turned the ac on lowest setting
> for 5 min and the adaprer prongs were too hot to touch.
> >
> > Is there a quick cheep fix or am I wasting my time?
> > --
> > Wayne Lawrence
> > 76 Birchaven
> > Bellflower CA
> > w.lawrence
> >
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.appliedgmc.com
1-800-752-7502

 

[slc]

> My original roof ac draws so much current (shore power) it will melt the
> motorhome to shore power line adapter. I tried the fan only on all 3 speeds
> for 10 min each and no problem. Then I turned the ac on lowest setting for 5 min and the adaprer prongs were too hot to touch.
>
> Is there a quick cheep fix or am I wasting my time?

----

The RV roamers are going through this now. They tend to try to run AC from their solar systems.
The roof top AC is a general PIG for POWER. Mine was the highest amp accessory that the RV had and I also
melted those plugs. One guys answer is to replace the plug every year.

There is not much you can do to an existing unit to reduce the power demand, it is built into the unit.
I think the amps are from 9 to 13amps that they DEMAND, that more than the microwave, which is my second highest
power demand.
heck my Norcold frige on 120vac is only about 3-4 amps.

You might try looking around to see if the manufacturers have smartened up and designed some more efficient
less load demanding AC roof units. It's probably not likely because there is no money in it for them.
They sell the watt busters because there is nothing else for the RVer to get.'

What the RVers in the Solar community are doing, and it won't work for us, is they are getting window AC units
that run about 4 amps, a low enough load demand that the Solar system can handle. The problem is how do you
mount that type of AC unit in an RV like the GMC??? It would be quite an effort to make one work for us, and
it can be done but most don't have the time or energy to want to do that.

--
GatsbysCruise. \
74GMC260 Former Glacier Model style. \
Waukegan, Illinois \ Keep those MiniDiscs Spinning \ MY GREYHOUND IS FASTER THAN YOUR HONOR ROLL STUDENT \ WindowsXP-Win7-Win8.1-UBUNTU STUDIO -
UBUNTU VOYAGER - Berzin Auto Center

 

[Ken B]

Any time you have heat, you have a bad connection or too thin wire. I just fixed one for someone that burned up two adapters. The usual fix is to
polish (clean) the connectors until they shine. Then bend in the female ones so there is heavy tension. I bead blast them when possible, except for
the main power cord because I cannot get it all the way to the bead blaster.

Then reassemble them and turn in on again. Start feeling the outside of all connections and the cable itself. If there is no heat then wait for 10
minutes under load and check a second time. Any place there is heat felt, you have a poor connection. I did find one power cable once that the heat
was coming from the cable itself. I cut back the cable about 2 feet and reinstalled the plug. Dissecting the cutoff piece showed that corrosion had
crept down the wires itself for a foot or so.

On the female ends tarnx, or soaking in slightly watered down Catsup will usually clean them up. I have also heard, but never tried, soaking them in
Coca cola.

Anyplace there is heat you have a problem.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

 

[charles boyd]

sir: 15 amp extension cords and adapters are not safe for A/Cs. If you must use an extension cord it needs to be a minimum of 30 amp rated and of
good quality wire and ends. 30' for 30 amps, 50' or more go with 50 amp set-up. Just my way of thinking..
--
C. Boyd
76 Crestmont
East Tennessee

 

[6cuda6]

Plus a/c systems take almost double the current at start up so your looking at upwards of 30amps then it will drop to the specified current from
there.... its imperative that you have a good connection and a cord able to carry the load.....your looking at at least 12 gauge wire extention cord
best would be 10 gauge for 25' or more but that gets big/bulky plus pricy.
--
Rich Mondor,

Brockville, ON

77 Hughes 2600

 

[Irish Rogue]

A bit off topic but - in response:
I had Leon (The Amish guy) install a 2 dr fridge/freezer (the 26’ size) in my 23’ about 3 years ago. He did a Gr8 job for reasonable /bargain price. Still working - very satisfied. I recommend him highly.
Mike/The Corvair a holic

Sent from my iPhone

>
> I bought an Atwood unit from Jim K just before parking the coach for 4 years!! It’s supposed to draw like a 13.5 k BTU unit while pumping out 15k worth of cold. The few times we used it it was great.
>
> In a separate thread I saw a link for the Amish fridge repair folks who also have refurbished ac units.
>
> Larry Davick
> A Mystery Machine
>

>>
>> My original roof ac draws so much current (shore power) it will melt the
>> motorhome to shore power line adapter. I tried the fan only on all 3 speeds
>> for 10 min each and no problem. Then I turned the ac on lowest setting for 5 min and the adaprer prongs were too hot to touch.
>>
>> Is there a quick cheep fix or am I wasting my time?
>> --
>> Wayne Lawrence
>> 76 Birchaven
>> Bellflower CA
>> w.lawrence
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

 

[Ken B]

A good 12 gauge cord will easily carry 15 amps or even 20 amps. Keeping it as short as practical also helps reduce voltage drops. The problem is
most people have 16 ga or 14 ga. extension cords, not 12 ga. I did an experiment once and with a 50 foot 12 ga. cord I saw a 2 volt drop with my AC
on high. The voltage was 122 at the wall where the cord was plugged in and 120 inside the coach at full AC load. Heck I have 12 ga. circuit runs
longer than that inside my house. I did once run a GMC on a 16 ga. 10 foot cord. The cord did get slightly warm.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

 

[jerry work]

Unfortunately it is worse than double depending on the head pressure, state of maintenance, and original design the start up draw can be up to five times the running amps. This is a big issue in the world of bus conversions where the goal is to run one or more ac units off of the house battery bank once converted to lithium battery technology. Sometimes you can and some times you can’t.

Jerry Work
Kerby, OR
————-
Plus a/c systems take almost double the current at start up so your looking at upwards of 30amps then
————-

 

[mark sawyer]

I haven't tried these, and they're not cheap, but the Micro-Air Easy Start soft starter seems like a possible solution...

Saw a video a while back where they started a fairly large marine AC system off an inverter with one of these.....

https://www.microair.net/products/easystart-364-3-ton-single-phase-soft-starter-for-air-conditioners?variant=30176048267

> Unfortunately it is worse than double depending on the head pressure, state of maintenance, and original design the start up draw can be up to
> five times the running amps. This is a big issue in the world of bus conversions where the goal is to run one or more ac units off of the house
> battery bank once converted to lithium battery technology. Sometimes you can and some times you can't.
>
> Jerry Work
> Kerby, OR
> ---------
> Plus a/c systems take almost double the current at start up so your looking at upwards of 30amps then
> ---------
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

--
Mark S. '73 Painted Desert,
Manny 1 Ton Front End,
Howell Injection,
Leigh Harrison 4bag and Rear Brakes,
Fort Worth, TX

 

[jerry work]

Marco is right. These soft start units make a high difference in trying to run an ac off of lithium batteries. While it is a practical no go with any lead avid battery it can be done with lithium batteries. More after the presentation at GMCWS.

Variable frequency devices out of industrial control systems make it not only possible but practicable for short (one to two hour) periods as well. Melt your wallet and several hours are possible. A long day of dry camping? Not yet and not likely any time soon. We have to wait for solid electrolyte lithium batteries for that. Don’t hold your breath. We might see that about twice the time all these recent FMCA renewals expire.

Jerry Work
Kerby, OR
.......
I haven't tried these, and they're not cheap, but the Micro-Air Easy Start soft starter seems like a possible solution..
.....::

 

[wayne lawrence]

I want to thank each and every one who replied. THANK YOU! You all reminded me of things I should have known
and saved me money and time.

I am using a 10/3 extention cord. But the end of the rv 30 amp plug is molded and was loose on the inside. replaced that and now cool.
I am kind of glad it happened as it started me checking things and I found an open in the ground wire of the dogbone.
--
Wayne Lawrence
76 Birchaven
Bellflower CA
w.lawrence

 

[john r. lebetski]

I need to retest my amp draw but from memory the larger front DuoTherm came in around 17A and rear smaller unit around 15A. A good 12Ga cord of short
length plugged into a 20A (not 15A) receptacle that is near the main panel will just run the larger unit for a short time. The continuous draw
causes heating Amp draw goes up with temp and humidity (latent heat). If everything was spot on I might be able to run the smaller unit on a 20A
receptacle for a continuous time.
--
John Lebetski
Woodstock, IL
77 Eleganza II

 

[tim]

I put an easy air soft starter on the original Dometic AC unit and now you can barely tell when the compressor starts. Before when the compressor
started you thought it was gonna come right through the roof.
--
1975 eleganza,
3 stainless steel fuel tanks holds 90 gal.,
Thorley headers and 3" SS exhaust pipe,
6 Wheel disc brakes,
Quad airbag system