Dual air

[pjude]

HI! I recenty bought a 86 345 and need some help! This unit is designed to only run one roof air at a time. I can run both if hooked to shore power and also run the genset. Being in TEXAS we need to run both units either on shore or on the genset. How do and where do I rewire the units so that I can run both at the same time?
Pete

[vswingfield]

Hi Pete,

Check out the thread at http://www.airforums.com/forums/f427...fit-33581.html Dual Air Retrofit. I posted a question about adding a second AC unit to my Excella and the responses and advice have been excellent.

Baughan

[vswingfield]

Originally Posted by vswingfield

Hi Pete,

Check out the thread at http://www.airforums.com/forums/f427...fit-33581.html Dual Air Retrofit. I posted a question about adding a second AC unit to my Excella and the responses and advice have been excellent.

Baughan

OK, it's late and I have been struggling with my old Coleman this evenging. The unit quit at 6:30 and it took me till 8:45 to get it working again. Needs a new switch on the unit. Have already replace the thermostat on the unit. Have only owned the trailer since January, the AC is the only negative so far.

That should read

Vaughan not Baughan

[pjude]

This 345 is equiped with 2 air units but I have to move a switch in the upper cabinet to run either the front air or the rear air. I need to run both units at the same time. I have an Onan 7000 generator so I have the amps needed but need to wire both units to the genset....any advice?
Pete

[jking]

Guys, the roof A/C draws 18 amps average when the compressor starts (sometimes as much as 23 amps). Your coach is wired for a total of 30 amps draw through the electric hookup wire. There is no safe way to use both a/c units on 'shore power'. Yoou can overheat wires and start fires. On generator power both will operate as factory wired - designed that way. - Jamie

[HiHoAgRV]

My SOB RV had a similar setup except the AC's would both run off of the gen, but only the front off of shore power. I located the wiring for the rear AC an installed a plug and socket. When I got to a camp, I would run a seperate extension cord from the newly installed rear AC plug to the 15A outlet on the camp hookup. The rest of the RV ran off of the standard 30A setup. Easier that rewiring the whole mess for 50A

[pjude]

Jking: I cannot run both units off of the genset. A switch above the micro limits the use to either the front or the rear AC except when I plug into shore power then I can use the front air from shore power and the rear from the genset...In Texas I need to run both from the genset while traveling.
Pete

[HiHoAgRV]

In my SOB, the transfer switch had the air's tied to seperate contacts. When pulled in, both airs were tied to the genset. When not pulled in, the rear air was dropped off (no feed to contact 2 from shore power). The answer to your problem lies in properly wiring of the transfer switch. I am making an assumption your unit has an automatic transfer switch and you don't have to replug stuff to run off of the generator. Depending on where the feeds are, it could be a pretty big job just routing the wires.
If you want both airs to run at camp you will need to convert to 50 amp or use a trick like I posted above.

[bkahler]

Originally Posted by pjude

Jking: I cannot run both units off of the genset. A switch above the micro limits the use to either the front or the rear AC except when I plug into shore power then I can use the front air from shore power and the rear from the genset...In Texas I need to run both from the genset while traveling.
Pete

Pete,

I know what you're dealing with, we have an 84 310 (and your 345) that is set up the same. On our 310 there is an automatic transfer switch under the passenger side rear closet. Under that closet you should find a circuit breaker box and a transfer switch box. The circuit breaker box is for the circuit going from the Genset to the rear air. The way the generator is setup is it will have two 120 vac circuits. One circuit is ONLY for the rear air and nothing else. The other circuit feeds the rest of the coach. In order to run the rear ac while on shore power you will need to break the line from just before the ciruit breaker where it comes from the generator that feeds the rear air and have a seperate connector that you feed directly from a 20 amp shore power ciruit. I'm going to be installing a double pole double throw switch so I can just select shore power or generator power for the rear air.

If you give me some time I can work up a sketch of what you're going to need to do.

Rest asured there is a way to do what you want but it will take a little rewiring. Nothing major fortunately.

Brad

[pjude]

bkahler...Thanks for your info but I'm being misunderstood. I can run both the units pluged into shore power if I also turn on the genset to run the rear air. What I want to do is run both units off of the 7000W Onan while traveling which I cannot do now and it is unbarable in the rear of the coach when the temps in Texas are in the 90's.

[bkahler]

Originally Posted by pjude

bkahler...Thanks for your info but I'm being misunderstood. I can run both the units pluged into shore power if I also turn on the genset to run the rear air. What I want to do is run both units off of the 7000W Onan while traveling which I cannot do now and it is unbarable in the rear of the coach when the temps in Texas are in the 90's.

Oops! Sorry about that. What you're asking for is the way the system was originaly designed. It sounds like the circuit breaker for the rear air only on the genset is turned off or tripped. There may actually be two circuit breakers involved. One on the genset and one on the passenger side probably under the closet. Poke around under the closet and see if you can find a single circuit breaker. Assuming you find it check to make sure its turned on. Also on the genset there is likely to be a circuit breaker for each circuit. Check to see that it is turned on and not off or tripped.

I'll look in my service manual which covers the 345 as well and see if it mentions anything specific about the 345.

Good luck!

Brad

[pjude]

Thank you for your interest and advice...it was a breaker on the genset that was tripped. The previous owner stated that it was not possible to run both units on the coach but I felt like there had to be a way since this thing gets sweltering here in East Texas. I also find it strange that Airstream would only put in 30 amp power. I have a 1973 Travco that I refurbished and it has 50 amp stock from the factory. Once again many thanks and I hope alls well
Pete

[bkahler]

Originally Posted by pjude

Thank you for your interest and advice...it was a breaker on the genset that was tripped. The previous owner stated that it was not possible to run both units on the coach but I felt like there had to be a way since this thing gets sweltering here in East Texas. I also find it strange that Airstream would only put in 30 amp power. I have a 1973 Travco that I refurbished and it has 50 amp stock from the factory. Once again many thanks and I hope alls well
Pete

Cool! (pun intended)

Glad I could help. I've received so much help from this forum that its nice to give something back.

I guess the 30 amp system was designed before most places had 50 amp service available.

We're not too far north of you here in Arkansas and just standing inside our MH without the air on and I start dripping sweat.

Brad

[mlmarch]

On my 345 i had an electronic relay added to allow for me to plug in the coach power(for one of the ac units)and also plug in another 20 amp feed so that I can run both units when camping without having to run the generator. The relay prevents potential electrical problems with the selection switch. System works great and saves wear on generator. Most campgrounds have the 30 amp plug along with another 15-20 amp outlets. I also had an adapter plug built so that if the campground has a 50 amp plug then i can plug my 30 and the 20 into my adapter then plug the adapter into the 50.

[bkahler]

Originally Posted by mlmarch

On my 345 i had an electronic relay added to allow for me to plug in the coach power(for one of the ac units)and also plug in another 20 amp feed so that I can run both units when camping without having to run the generator. The relay prevents potential electrical problems with the selection switch. System works great and saves wear on generator. Most campgrounds have the 30 amp plug along with another 15-20 amp outlets. I also had an adapter plug built so that if the campground has a 50 amp plug then i can plug my 30 and the 20 into my adapter then plug the adapter into the 50.

Any chance of posting some pictures of the installation?

Thanks,

Brad

[pjude]

How did you get the relay work done....yourself or electrician. Can you further explain how the system is installed?
Thanks,
Pete

[mlmarch]

i had the local airstream service company do the original installation and he used a magnetic relay and it later failed. I had it replaced with an electronic version. There is also a simpler way where you cut the feed to one of the a/c units and reconnect with an outlet and plug. when the gen is on you have the plug attached to the outlet-when at shore power unplug the gen and then plug in another cord that is attached to shore power. The key is that you cannot have the gen and shore power capacity to be connected at the same time or you will feed 220 to the ac unit. My relay auto switches to prevent this. I probably would have set it up with the dual plug due to less cost if i had known that at the beginning. The plug is located in the gen compartment and has a cover to protect it. The cord from shore power feeds thru the bottom of the compartment and that way you can close the front grille. The 345 needs both ac units going when it gets in the 90's both on the road and parked.

[mlmarch]

The relay is mounted under the bench seat that is closest to the driver. you open the cabinet door and it is facing you. That way the relay is protected and is accessible and close to gen compartment. The key again is to prevent both shore power and gen from both feeding the ac unit. You can do it with the relay or by unplugging and plugging is different cords into the added outlet inside gen compartment.

[bkahler]

Originally Posted by mlmarch

The relay is mounted under the bench seat that is closest to the driver. you open the cabinet door and it is facing you. That way the relay is protected and is accessible and close to gen compartment. The key again is to prevent both shore power and gen from both feeding the ac unit. You can do it with the relay or by unplugging and plugging is different cords into the added outlet inside gen compartment.

I've been planning on using plugs for the shore line conversion. Just haven't had the time to do it. Underneath the passenger closet is where all the boxes are on a 310 and I'm just going to put a plug there.

Brad

[3 Dog Nite]

The PO of my 345 told me he has run both a/c units off the genset while driving. He said turn the switch to the rear unit & start it. While it is on, flip the switch to the front unit & turn it on. I tried this once in my driveway just to see if it worked (it did). After 3 minutes, I turned it off. I don't know if the units were safe to run like this and anticipate checking the systems out before I do it for an extended period of time. I suggest you do the same.