Running rear air when docked

[bkahler]

Fred,

Here is a short article with sketches I wrote to describe how the 120 VAC system on the motorhomes is supposed to function.

http://www.airforums.com/forums/f311...ion-41259.html

Brad

[ftbjc]

Here is a short article with sketches I wrote to describe how the 120 VAC system on the motorhomes is supposed to function.

http://www.airforums.com/forums/f311...ion-41259.html

Brad, Thanks, I saw your article and have already printed off the scketches, I plan on tracing my system to see if it is the same. Do you have twins in the bed room or a queen?, it might make a difference on where the items are located. Thanks for the help!

[bkahler]

Originally Posted by ftbjc

Here is a short article with sketches I wrote to describe how the 120 VAC system on the motorhomes is supposed to function.

http://www.airforums.com/forums/f311...ion-41259.html

Brad, Thanks, I saw your article and have already printed off the scketches, I plan on tracing my system to see if it is the same. Do you have twins in the bed room or a queen?, it might make a difference on where the items are located. Thanks for the help!

Ours is a rear twin. You should find a small breaker box on the right hand side of the opening and the transfer box to the left laying on top of the wheel well.

Have a good flash light handy or a trouble light as its a small opening and its dark in there!

Brad

[ftbjc]

[QUOTE]

Originally Posted by bkahler

Ours is a rear twin. You should find a small breaker box on the right hand side of the opening and the transfer box to the left laying on top of the wheel well.

Originally Posted by bkahler

Have a good flash light handy or a trouble light as its a small opening and its dark in there!

Brad,
I took the drawer out, opened the cabinet door under the drawer, got myself a nice light, and found nothing. I thought maybe the P/O might have moved the transfer box at first, but there are no screw or wire holes thru the wall anywhere. I wonder if Airstream wired the motor homes differently for some reason. I have found only the one transfer box and it is in the same compartment as the wire reel. Any ideas?, Will keep looking in the mean time.
Fred

[bkahler]

Fred,

Another way to try and find the second transfer box would be to trace the power feed cable coming from your generator. The power cable has to enter the coach somewhere and if your coach is wired like mine it will lead to a circuit breaker box with one circuit breaker in it. The feed from that circuit breaker box should then go to the second transfer box (assuming yours has a second transfer box).

What model and year is your motorhome?

Brad

[ftbjc]

What model and year is your motor home?

I have an 84' 310 limited with twin beds in the back, I have traced the wiring coming into the M/H from the generator. One lead goes to the circuit breaker box and then into the wall, straight up to the rear A/C unit. the other lead goes to the Univolt system under the slide out cabinet, under the microwave, next to the frig. I don't think I have a second box or a rotary switch like others have talked about. The only switch I have is next to the exhaust fan, over the stove, which can be switched back and forth for the front A/C or microwave.

[bkahler]

Originally Posted by ftbjc

What model and year is your motor home?

I have an 84' 310 limited with twin beds in the back, I have traced the wiring coming into the M/H from the generator. One lead goes to the circuit breaker box and then into the wall, straight up to the rear A/C unit. the other lead goes to the Univolt system under the slide out cabinet, under the microwave, next to the frig. I don't think I have a second box or a rotary switch like others have talked about. The only switch I have is next to the exhaust fan, over the stove, which can be switched back and forth for the front A/C or microwave.

Fred,

Our motorhome is a 1984 310 Limited. It sure looks like your coach didn't come fitted with the 2nd transfer box. Also makes me wonder if the 2nd transfer box might have been an option.

Based on your description you can pretty much throw away the write-ups that I did. They won't work for your coach at all.

Sorry about that.

Brad

[ftbjc]

I tried to find the missing box but it would appear that My M/H only has the one. This is as simple a fix I could come up with and after taking the Motor home out for the four day memorial weekend it appears to work. I traced the line coming from the rear A/C to the gen set. I have twin rear beds and the wiring came in on the curb side, under the bed. I found there were two leads coming into the coach, one feed the Univolt system the other went to the rear air. I disconnected the incoming which fed the rear a/c from the gen set. On the rear (driver) street side of my m/h is the compartment that houses the power reel (120 volt plug) as well as the air pump. I ran two Romex lines from this compartment up through the floor, around behind the three drawer chess between the beds. I mounted a two plug electric box on the inside of the compartment wall and connected one of the Romex lines. The other end of this line I connected to the original a/c lead from the generator (when the generator is running the plug is hot). I bought a motor home 30 amp extension cord, removed the female plug and connected it to the other Romex line. Under the bed on the gen set side, I mounted a 30 amp circuit breaker. I ran the leads from the a/c into one side of the 30 amp and the extension cord into the other.
I now can run the rear air by plugging it directly into an outlet, or if I want to run it using the generator, I can plug into the new plug. I hope this will help anyone who is having the same problem I had with my rear air.

[bkahler]

Fred, I'm curious does your coach have any mounting holes that might have been used by a 2nd transfer switch? The holes would be under the passenger side closet in the compartment with the pull down door. Ours is bolted to the top of the fender towards the front of the coach.

Did the one generator lead ONLY feed the univolt or did it feed the rest of the coach as well?

When I get home this weekend I'll try and remember to take a couple of pictures and post them.

Glad you got something worked out!

Brad

[ftbjc]

Quote,
"Fred, I'm curious does your coach have any mounting holes that might have been used by a 2nd transfer switch?

Did the one generator lead ONLY feed the Univolt or did it feed the rest of the coach as well?"



Brad, I've looked high and low for any sign of a second box, or any sign that a second box had even been there. I've looked in the location under the closet where your's is and found nothing, not even a screw hole where it might have been. The second lead from the generator did feed the rest of the coach as well as the Univolt system

[raveson]

If your coach is at all wired the same as my 89 345LE, look in the gen compartment. Both the 30 and 20 amp leads go to a 4x4 junction box on the right side of the compartment. The power solution system I installed gives you all the directions as to how to tap into the box with changes and an additional box on top of the existing. Basically the modifications allow you to use the 20 amp gen circut and add a additional shore power cord when docked. I have been using mine for a couple of years without any problems.

[bkahler]

Fred,

Just to show I wasn't making up the the transfer switch and circuit breaker on our 84 310, here are some pictures to prove it

Its a real mystery to me why Airstream would use two different (at least two) wiring schemes on the same year and model motorhome

30 amp Circuit Breaker box.


Rear A/C transfer switch.


Rear A/C wiring under passenger side closet.


Glad you got your system sorted out. If you're like me its one more item you can cross off your to-do list

Brad

[ralley]

Gentlemen: I have been reading this with some interest. Of course, our 350 is wired differently than anything mentioned here, in that only the REAR AC works when plugged in to shore power. Running both AC in the 350, if I read the AS manual that came with the vehicle correctly, appears to require running the generator. I do not remember anything in the manual about both AC actually running off the generator when it is running--but I suppose that this is quite possible for a 7K watt generator.

Is there a work-around to allow running both AC off shore power without the use of an additional 20 amp power cord? (pluging into 2 discrete shore power recepticles?) Does the running of both AC units at the same time (although not started at the same time) on the same shore power circuit require 50 amps?

We spend a goodly amount of time on weekends in places where only 30 amp service is available, and additional 20 amp circuits are not. I like using the genny only for emergencies, not routine use.

It's late, I'm tired, and I'm probably missing something--somebody please straighten me out!!

Best to all,

R

[str8strm]

The genny will run both the front and rear AC; when on shore power with NO modifications you can only chose to run one option: microwave, nutone, front air, rear air, etc. on our 85 345.

[klattu]

I wanted the same, but must be cheap, simple, idiot proof.

A 12ga. extension cord was added directlt to the AC power supply point.
The cord runs down the wall behind the acordian door, then into the rear storage box.
The cord stays in box until needed, then is run out and under to 20 amp power supply.
A double throw/double posistion switch is installed at power supply point too.
This totaly isolates AC from either Generator/30amp switch above stove, and the 20amp power cord.
Never can power come from both directions, and never any feed back to the generator.

A = Center connecters are power supply out to the AC
C = 12ga extension cord (red)
G = Power from generator or 30 amp with switch over stove set to rear AC




To locate switch center











Of course after all this work, I find a nice hole alread in place on the shroud.
The shroud was painted white while it was down.
Krylon plastic does good, but so many colors, white seems dull.
Forward is Gen
Rear is cord



Tested in very hot Florida during the 4th.
I let both run all day and night.
Camera would fog up when taken outside.
And sleeping under blankets was nice.

A nice extra is that if one breaker trips while I am away, the other is a kinda back-up.

Plus now I can use microwave and keep the rear AC going.

[klattu]

Don't panic...the DPDT switch is rated at 20amps 120volts.
(with a center 'off' position, is that a triple throw?)

Left this out...
If your diffusers don't stay put...a small O-ring on the end of one side works great.

[Jenniflow]

This is a great thread, but I know it's a little on the stale side. I figured this question was worth a try, though.

I called Power Solutions to see if they still sold that kit, but the phone was disconnected. Does anyone happen to know if they became another company and are still selling it? Or whether anyone else is selling it?

I suspect this will be harder to find as 30 amp rigs are less common (aren't they?), but I still have this 1986 345 moho and I am still hoping to run both a/cs on shore power!

Thanks!

[bkahler]

Jenni,

There are a lot of threads on Airforums discussing the various methods for upgrading to allow the rear air to run at the same time as the front when on shore power.

As mentioned above I did it to the 310. Are you planning on doing the work yourself or having someone else do it?

Brad

[Jenniflow]

Hi Brad,

I was planning on having a mechanic or technician do it.

I just found this thread, from someone's recommendation on a thread I started, lamely. I'm slammed at work, so I just went with this one.

What were you thinking about it?

Thanks,

[bkahler]

There are a variety of ways to tackle the problem. The easiest (to me anyway!) is the way I did it on the 310.

Below is the thread with the sketches I made.

310 Rear AC mod

The only thing I changed was instead of using a 3-prong plug I actually installed a double pole 30-amp switch. When the switch is one direction a new shore power cord is tied to the rear AC. When it's switched the other direction the rear AC power comes from the generator or the selector switch up in the kitchen area as originally set up from the factory.

From what I remember about the 345 wiring it shouldn't be any more difficult than the 310 was.

Take a look at the sketches I attached in the linked thread and let me know what you think.

Brad