Community Forums

KSagal · 03-16-2015, 08:18 PM

In my recently purchased 88 Fleetwood Southwind MH, I have found an interesting situation.

I have two roof air conditioners, main salon and back bedroom.

I also have a 30 Amp shore line service.

In reading the manual, and seeing the instructions on some switches, I see that I am instructed to only run one or the other air conditioner while on shore power, but can run both while the generator is running.

I presume that the 30 A ground line cannot supply enough current for both while the generator can.

So...

I wonder if there is a way to run a separate power source for the 'other' air conditioner, or to upgrade the 30 a service to 50 a.

HuntingHawk · 03-16-2015, 09:56 PM

Research upgrading to a 50amp shore service.

Mr_D · 03-16-2015, 10:09 PM

Quote:

Originally Posted by KSagal

I wonder if there is a way to run a separate power source for the 'other' air conditioner, or to upgrade the 30 a service to 50 a.

Some have run a seperate power line to the rear gen, others have upgraded the service to 50 amp. You need to have a sub panel and split the circuits correctly to do the 50 amp upgrade though. Not a simple job for most do it yourselfers but it can be done.
Our Magna has three 15.0 heat pumps and the dryer is a 240V home style one. So have to have a 50 amp shore power to run everything unless we cut back or run the gen set. Or, if there's a power management system it's built in. And yes, the dryer really is a 240! I've verified that with the manuals for it as well as online. With the previous Dutch Star I could run both 13.5 heat pumps on 30 amps as well as the Splendide but not all at the same time naturally.

HoneyBadger · 03-17-2015, 08:58 AM

Yes, it can be done. We did it with a purchased unit called a Dual Power (no longer in business) that let us run a separate 30amp power cord to the rear AC so we can plug both main power and the rear AC into a 50 amp power source at the same time.

I wish I could tell you exactly how its wired, but its been 10 years since we did it. Ask someone with good electrical knowledge who understands the wiring in your coach.

You need to identify the wiring which runs from the gennie to your rear AC, then establish a junction box there to run out your supplemental 30 amp cord, and then have a control box so you can shift from gennie power to shore power.

Its one of the best things we ever did in our 89 Southwind.

QuietWater · 03-17-2015, 09:18 AM

I hope this link still works. It was posted quite some time ago on a different forum. It shows how to do just what you want to do.
RV.Net Open Roads Forum: How to run two AC's with 30 Amp Service UPDATE UPDATE

Dan

puttin · 03-17-2015, 10:52 AM

The mod that comes from RV.NET would run 2 a/c's only if you were on shore power or had another stand alone power source while using the generator. Someone else posted that they have 30a. service but were able to run both a/c's...actually you'll only hear the fan, the second a/c's compressor isn't running. If you add the loads of both you'd see you're bumping up against the 30a limit pretty closely. The only real remedy is to convert to 50a and it's a fairly big project. I'd carefully consider wheather or not you really need that second a/c going all the time.

wa8yxm · 03-17-2015, 11:35 AM

Short answer to your question is yes. I can even tell you how...

First: There used to be a company (PSRV) but last I checked.. but the domain is for sale.

Identify the last wire that takes power to the A/C... This should be in the bundle that connects the Generator to the Auto Transfer Switch.

Break out that lead (Re-route it, or route it to one or two junctions boxes

USING 12 ga wire extend to a spot where you can put in a plug and socket. Use 15/20 amp outlet on the "non-AC" half of the line and .. Well, I'd like to use a 20 amp plug on the A/C side but PSRV used a 15 amp plug on theirs.

(20 amp plugs the two flat blades are perpendicular instead of parallel)

PSRV then ran the "Plug" end (Actually they used an INLET, The Outlet was on a pigtail) to a 20 amp breaker,, Then back to the air conditioner.

Use a 12ga Extension cord to the park 20 amp outlet....I like the ones Sears/K-Mart sell with the push button on the outlet

Original wiring

Breaker box,Front/rear switch/ATS/Generator------------------A/C

new setup

B-Box/Switch/ATS/Genny-----Outlet/Plug--Breaker---A/C

Does this help?

ARTWERKE · 03-17-2015, 11:51 AM

I had an 89 Southwind 30' with 2 ACs , I modified to run both on shore power where there was a seperate 15-20 amp circuit on the pedestal. There is a junction box right in front of the generator that ties the 2nd generator output to the 2nd AC. I tied the generator output to a 120 v 15A outlet, then put a 15A plug on the wire going to the AC. when on shore power run an extension cord from the plug to the pedestal, whe on generator ,plug the AC into the new outlet by the generator. Set the AC selector to either front or rear and both ACs should work. If this sounds too complicated get an electrician to do it. I don't want you to get hurt.

QuietWater · 03-17-2015, 02:39 PM

ARTWERKE, In spite of what puttin wrote, doesn't the RV.net link show the same thing you posted?

KSagal · 03-17-2015, 03:10 PM

Great replies.

I believe I will use the RV.net link (thanks QuietWater) or the suggestions from Artwerke or wa8ysm, as they all have parallels that I understand.

I do not believe I will upgrade to 50 amp service, at least not right away.

I do not do this for lofty reasons, however, but because I am a cheap guy...

I can run an additional power source for the 2nd airconditioner when needed, and that is simple enough, and I have already run a 30 amp service to my pole barn that I made for the MH.

Problem is that I did this years ago, before I had any MH. I ran 220 out to the shed, and put a sub panel out there, 150 feet behind the house. I did this to run the 110 volt lights in the trees, and to power the various out buildings (I have 3 sheds in addition to the pole barn) but also because I have my house emergency generator out there too. (this places the noise farther away from the house.)

I back feed the whole house with that 220 line when necessary. I only built the system at 30 amps. Then when I got the MH, I tapped into this power.

Now, If I were to upgrade to 50 Amp service in this motorhome, I would have to redo my back yard electrics as well.

Too much work for this lazy guy. Also, I live in New England. Not enough need for both air conditioners often enough to justify all that rebuilding.

I can add the separate power option with a great deal less rebuilding of the MH or the back yard.

One last twist. I have two switches in one of the front cabin cabinets that dictate how the power is distributed, one being a generator option the other being a land line option. I believe this convenient place for these switches may mean that the wiring for these air conditioner may make a longer and more convoluted path than would otherwise seem prudent. Oh well.

Thanks again for all the great data.

puttin · 03-17-2015, 04:29 PM

All,

When you separate the feed to the 2nd a/c (as illustrated by the RV.Net link) then it will not be surge protected anymore...unless you have a 2nd surge protector for the 20a outlet you wired up. And, as I stated before, you still won't be able to use the second a/c while on the generator.

QuietWater · 03-17-2015, 09:39 PM

Puttin, I don't wish to argue the point, but read the post again. There is a yellow wire with a plug that goes into either of two outlet boxes. When on the Aux outlet the AC is on a separate line. When the plug is switched to the Gen outlet it is back to original. You can run both ACs on generator or one or the other on shorepower. It is a pretty slick setup.

Mr_D · 03-17-2015, 09:57 PM

Quote:

Originally Posted by puttin

The mod that comes from RV.NET would run 2 a/c's only if you were on shore power or had another stand alone power source while using the generator. Someone else posted that they have 30a. service but were able to run both a/c's...actually you'll only hear the fan, the second a/c's compressor isn't running. If you add the loads of both you'd see you're bumping up against the 30a limit pretty closely. The only real remedy is to convert to 50a and it's a fairly big project. I'd carefully consider wheather or not you really need that second a/c going all the time.

NOPE! Both heat pumps ran and produced heat or cool depending on their settings at the same time with 30 amps. I know, we did it for over 12 years with the Dutch Star.

puttin · 03-18-2015, 06:23 AM

Quote:

Originally Posted by QuietWater

Puttin, I don't wish to argue the point, but read the post again. There is a yellow wire with a plug that goes into either of two outlet boxes. When on the Aux outlet the AC is on a separate line. When the plug is switched to the Gen outlet it is back to original. You can run both ACs on generator or one or the other on shorepower. It is a pretty slick setup.

Got it, I only saw the first picture with only one outlet box. You'd still have to figure out how to protect the second a/c when on shorepower though.