Community Forums

Firstpoet · 07-11-2021, 01:02 PM

Our 97 Southwind has 2 ACs and 30 amp service so when at the parks and plugged in only 1 at a time can be ran successfully. I see how folks talk about the 2nd AC being plugged in on shore-power separately using the 120/110 volt secondary plug that is at most parks. My question is 'how' do you do that - where do you break-out/Y-out the power so you can run an independent extension cord for the 2nd AC?

Can anyone provide guidance or a link to 'how' this is done? I'm somewhat handy and can do it if I know how. I've searched this and other forums but they all seem to discuss 'adding' a 2nd AC, not rewiring so you can plug the existing one in separately.

Thanks so much and safe MH'ing!!

twinboat · 07-11-2021, 01:11 PM

Haven't done it, but some find the wire to the second AC and cut it.

The put standard AC plugs on each end so that they can plug them back together for normal use.

When they want to run both, just unplug the 2 plugs and run an extension cord from the male plug to the power pedestal.

That can be done at the generators 20 amp output line.

Firstpoet · 07-11-2021, 01:13 PM

Thank you very much!

jacwjames · 07-11-2021, 01:26 PM

The previous owner of my coach made the modification. Both AC are hardwired using a metal Jbox. The previous owner simply added an outlet in the Jbox in the bedroom and a male plug end on the wire going to the AC unit.

If I wanted I could just pull an extension cord in through the wind, pull the AC filter door down, plug the AC into the extension cord. The AC unit still is controlled by the thermostat.

Tha_Rooster · 07-11-2021, 01:44 PM

When I had a 1994 suncruiser I installed a (double pole double throw) switch with a separate wire and plug for rear air. I could run both airs that way.

amosnandy · 07-11-2021, 02:11 PM

First, if you have 2 ac units in a 30 amp panel it is likely that someone added the second ac unit. Pull up the specifications on your rig and see if it came with 1 or 2 ac units.

It may be easier if it was added on, as someone may have already installed a box to connect the second ac. Either way I am sure each unit is on its ow circuit breaker.

Either way you could disconnect the one ac unit from the main distribution panel and install a box for it independent of the main panel. Then just run Romeo cable down into a separate box with an inline breaker on it and wire a good 20 amp extension cord that plugs into the pedestal.

Keep in mind however, if you are on a CG pedestal that has only a 30 amp and 20 amp outlet, you still likely can only draw 30 amps. It’s not 30 + 20 because the larger breaker generally feeds the smaller breaker. On a pedestal that has a 50 amp breaker you’d be fine.

You might want to do a little searching on putting soft start or easy start units on your ac. Starting is where all the load comes in and there’s lots of threads about running 2 ac units on 30 amp or with a small generator.

Firstpoet · 07-11-2021, 02:17 PM

Thanks - the MH came with 2 AC's from the factory and I understand that this will only work when the pedestal can provide all the amps needed - I've heard how folks have broken this power out for the 2nd AC and am wondering how they did it - I can run both on the generator but not on shore power as the coach is only 30 amp -

Flyer 516NG · 07-11-2021, 03:34 PM

Quote:

Originally Posted by Firstpoet

Thanks - the MH came with 2 AC's from the factory and I understand that this will only work when the pedestal can provide all the amps needed - I've heard how folks have broken this power out for the 2nd AC and am wondering how they did it - I can run both on the generator but not on shore power as the coach is only 30 amp -

I had a 2000 Southwind. It had an EMS, when the EMS sensed too much load it would shed the #2 compressor. If it was still seeing too much load, it would shut the #2 /ac off completely.

I had a 1997 Jayco class c with a 30 amp service. I put the a/c on a cord by itself that I could plug in to the pedestal, or run it off of the coach power. It wasn't a real "sanitary" way that I had it done, and could have been sort of dangerous for some unsuspecting soul. But when I traded it in, I took the extra cord out and returned it to OEM.

amosnandy · 07-11-2021, 04:14 PM

Quote:

Originally Posted by Firstpoet

Thanks - the MH came with 2 AC's from the factory and I understand that this will only work when the pedestal can provide all the amps needed - I've heard how folks have broken this power out for the 2nd AC and am wondering how they did it - I can run both on the generator but not on shore power as the coach is only 30 amp -

Well now that’s an interesting setup. That they would build a coach with only a 30 distribution panel but with more appliances than 30 amp can run.

How big is your generator? The generator should also feed through the distribution panel that only has a 30 amp breaker? Or is there another panel that handles additional load while on generator. I would think if you are tripping the 30 amp main on shore power you would also trip it on generator, no matter what the generator is capable of putting out.

Where is your distribution panel in relation to the transfer switch and shore power cord? If they are close to each other, hopefully directly above the electrical bay, it’s possible, if there is room, to take the breaker out, disconnect the hot, neutral and ground, put in a junction box, and run another wire, preferably 12/2 romex down into the electrical bay, put another junction box, with a breaker connected to a good 12 gauge extension cord. Then just stow the extension cord in the bay just like you do your 30 amp cord.

I’m going to assume on a coach that old there is no EMS that shuts stuff off on an overload. But even if it did since you are removing one high amp draw from the 30 amp distribution panel it would still work as usual.

All that said, if the distribution panel is close enough to the transfer switch, it might be just as easy to upgrade the distribution panel to 50 amp. That would require pulling a new wire down to the transfer switch, possibly a new ATS and a new 50 amp power cord. What the hell, to run the extra AC you have to have more than 30 amps at the pedestal anyway.

twinboat · 07-11-2021, 04:19 PM

Quote:

Originally Posted by amosnandy

Well now that’s an interesting setup. That they would build a coach with only a 30 distribution panel but with more appliances than 30 amp can run.

How big is your generator? The generator should also feed through the distribution panel that only has a 30 amp breaker? Or is there another panel that handles additional load while on generator. I would think if you are tripping the 30 amp main on shore power you would also trip it on generator, no matter what the generator is capable of putting out.

Where is your distribution panel in relation to the transfer switch and shore power cord? If they are close to each other, hopefully directly above the electrical bay, it’s possible, if there is room, to take the breaker out, disconnect the hot, neutral and ground, put in a junction box, and run another wire, preferably 12/2 romex down into the electrical bay, put another junction box, with a breaker connected to a good 12 gauge extension cord. Then just stow the extension cord in the bay just like you do your 30 amp cord.

I’m going to assume on a coach that old there is no EMS that shuts stuff off on an overload. But even if it did since you are removing one high amp draw from the 30 amp distribution panel it would still work as usual.

All that said, if the distribution panel is close enough to the transfer switch, it might be just as easy to upgrade the distribution panel to 50 amp. That would require pulling a new wire down to the transfer switch, possibly a new ATS and a new 50 amp power cord. What the hell, to run the extra AC you have to have more than 30 amps at the pedestal anyway.

Back in 1997, most RVs were 30 amp, even the long ones.

They installed 5500 watt generators with both a 30 amp and 20 amp output, the 20 amp being only for the second air conditioner. If it was real hot, you started the generator.

On shore power only, you had a choice of front or rear air.

I don't think energy management systems were very popular back then either.

50 amp service is 120/240 volts with a double breaker, requiring a completed replacement of all incoming components, including the breaker panel.

RichKimball · 07-12-2021, 09:08 AM

Quote:

Originally Posted by twinboat

Haven't done it, but some find the wire to the second AC and cut it.

The put standard AC plugs on each end so that they can plug them back together for normal use.

When they want to run both, just unplug the 2 plugs and run an extension cord from the male plug to the power pedestal.

That can be done at the generators 20 amp output line.

This is what I have done on my other coach. I did construct a 50a shore plug with a 30a and 20a pigtail each wired to its own hot line sharing a neutral and ground. One for the 30a coach and one for 20a a/c line. The caveat there is proper CB protection. I did add a box inside the coach with a 20a breaker in it for when I was using the extension cord to power the a/c, but the coach was relying on the inside mains breaker for circuit protection. Probably not the best. But I've seen folks use a pigtail adapter plugged into 50a service and then plug their 30a rv plug into the adapter...thinking the 50a service was better. Hmmmm

MarvinG · 07-12-2021, 09:57 AM

Actually, those old 30 amp energy management systems are quite good. Mine will run both AC’s at once on 30 amp pedestal. If it sense the voltage is low, it will shed one or both as needed until voltage sensing shows it can bring one or both back. And as pointed out, the generators had the secondary output for the AC alone.

Now the remote temperature sensing on those units is not so good. I’ve broken the yellow wire going to the AC with a battery operated digital thermostat and now have great temperature control as well as still have the working energy management system.

Adding a soft start device would be helpful but not really needed if generally on shore power. I’ve toyed with breaking the line from the generator to the 2nd AC so I could run it on a separate circuit as described in previous posts on this thread. I’ve never done it because I do fine without out. . . . So far. But I can’t run the microwave and the 2nd AC at the same time.

RichKimball · 07-12-2021, 10:01 AM

I did the same as to the thermostats Marvin. Put in 2 separate DC powered thermostats as the temp swing could be as high as 5 deg sometimes. Worked great.

And it was those times in high heat that running the microwave to make supper and killing of the 2nd a/c where that was a big problem. Even restoring power to the a/c...it still takes about 15 minutes for it to begin cooling again.

Firstpoet · 07-12-2021, 01:47 PM

Our MH from the factory is a 30 amp and has 2 ACs - it's a 1997 - my question was where do you split the power so you can run the 2nd AC using a simple extension cord...I appreciate all the replies - I'm looking for someone that has done this - the MH was not customized or anything weird in the configuration - it is a 1997 with the original electronic set-up - thanks very much!