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BlunerBill · 07-05-2018, 05:41 PM

I have a low mileage, nearly new 2001 Class A Winnebago Adventurer that I lost a generatior in a couple years ago up in New Jersey . Knowing I wanted to use it to go across America we bought a new replacement and installed it ourselves. No problem, disconnect the gas line, the electric wiring and 4 bolts and down she comes. Reverse procedure and we’re driving across the country with AC on and in Phoenix the Basement AC konks out! A trip to Home Depot netted us a stand alone in the floor temporary solution. So we purchased a new Coleman replacement AC unit and when the local RV dealer called us and said you could hang meat in there it’s so cold, we went to pick it up. It was sitting in the staging area and I went in, started the generator and kicked on the AC .... nothing. So the guy said it worked on shore power and plugged it in to prove it. Indeed it did. They’ve done everything they know to get it to run on the gen-set. They’ve tested everything they know to test including the transfer switch. EVERYTHING seems correct but I still don’t seem to get power to the new AC system on the generator. Any ideas?

jelag · 07-05-2018, 06:30 PM

This is too complicated for this forum... any good AC electrical guy should be able to trace this down and solve it....

Do other items (120V) work when the Gen Set is running?

I don't know you skill level but when you plug into a 50 amp service your actually plugging into two sides of the service panel... your getting (2) 120v legs... on a common wired cable, its 120 vac across the red and white wires and a second 120 vac leg across the black and white wires... and if you were to test across the red and black wires you'd have 240 vac....

Most electrical boxes for an RV have two main breakers... each runs one side of the 50 amp service.. in my unit I have (2) 25 amp circuit breakers and one of my AC units runs off one of the 25 amp breakers, and the other AC runs off the other 25 amp breaker... you need to look to see if in fact you have two breakers and see which side of these breakers that the AC breaker is on.

You might have only one leg of the transfer switch that locking in... and only one side the service panel is seeing the 120 vac service when the generator is running.

These are simple tests, and I don't understand why the guy who installed the unit can't diagnosis the problem...

Hope this starts to get you on the path....

Jim18655 · 07-05-2018, 07:13 PM

Winnebago shows a 50 amp and a 30 amp service for a 32' Adventurer ( from your profile). Which do you have?

http://www.winnebagoind.com/diagram/2001/132292.pdf

twinboat · 07-05-2018, 07:21 PM

What size is your generator. Anything over 4000 watts has 2 outputs with a double or 2 breakers.

Check them.

BlunerBill · 07-06-2018, 08:54 AM

I should have mentioned in my original post that it is a 30 amp motor home and it is an Onan 5500 as I recall. The RV is not in my presence at the time so it’s hard to remember something I changed a year and a half ago. But it’s today’s replacement for what I had. The two breakers on the generator are in the On position and Has been tested at the shop where it is now. The two breakers in the box left of the step are in the On position and everything else seems to work fine on shore power or with the generator. He said he tested the transfer switch (which is something I was not aware of) and there is power on both sides as was designed to be. It has me at a loss and their AC/Generator guy too. I thought I’d take this conversation to him to read. Thank you all for responding and hopefully it will give him some information to think about and maybe spawn an idea that gets me back on the road.

Ljwt330 · 07-06-2018, 10:28 AM

Quote:

Originally Posted by BlunerBill

I should have mentioned in my original post that it is a 30 amp motor home and it is an Onan 5500 as I recall. The RV is not in my presence at the time so it’s hard to remember something I changed a year and a half ago. But it’s today’s replacement for what I had. The two breakers on the generator are in the On position and Has been tested at the shop where it is now. The two breakers in the box left of the step are in the On position and everything else seems to work fine on shore power or with the generator. He said he tested the transfer switch (which is something I was not aware of) and there is power on both sides as was designed to be. It has me at a loss and their AC/Generator guy too. I thought I’d take this conversation to him to read. Thank you all for responding and hopefully it will give him some information to think about and maybe spawn an idea that gets me back on the road.

Re: bold, above.

The only thing I can offer is to ask if your coach has an Energy Management System that distributes AC to various outlets to avoid overloads. Don't even know if that's applicable to 30 amp units, but it's something that would be in between the power source, the transfer switch and house panel, and the outlets.

Quincy · 07-06-2018, 10:59 AM

I don't know why it is too complicated for this forum. Some of the posters like 007 or Twinboat, Old Biscut and many others are more than capable of sorting this out. Before they offer the solution I would offer my 2 cts. Look at the electrical components that are not in the circuit when the rig is on shore power. The parts that are supplying power to the AC unit only when the rig is on Gen power. Good luck and keep us in the loop.

Rkesselus · 07-06-2018, 11:35 AM

I am a little confused. This is a replacement unit, Correct? If the old unit was working and was 220 and the new unit is the same as the old one I would question the tech. that installed the unit as that is the only person who messed with the AC connections. If I missed something here just shoot me. Richard

YC1 · 07-06-2018, 11:39 AM

I would see if the 110 volts is present inside the AC under both conditions.

I would also see if 12 volts is present inside as well.

Not knowing what "modifications" have been made on purpose or by accident it is indeed a bit hard to diagnose remote controlled but if a tech can't give you that basic information you need to go elsewhere.

I often found tidbits of information from customers would not be given to me until I asked the same question several different ways. A tiny clue they thought was not related would lead me to the resolution.

I have diagnosed thousands of things over the phone in my 50 years as a service manager and owner of an electronics company.

twinboat · 07-06-2018, 11:40 AM

The second output of the generator may run the AC. A 5500 watt generator has 2 outputs, one for normal 30 amp operation and the second 20 amp output for a second air conditioner, or so you can heat water and microwave at the same time..

If the AC also runs on 30 amp shore power, there is a second transfer switch that selects between the inputs.

Tell your guy to follow the 20 amp breakers wire from the generator to its destination.

The 30 amp breaker, from the generator, goes to the normal shore cord transfer switch. The 20 amp goes to another one.

.