Second Air Conditioning compressor only comes on when plugged into 110 volts, not whe

[bobpie]

I am having trouble with my basement air.
When I am running my generator the second compressor does not come on.
Noting that in 85-90 degree weather it gets hot in the coach
Air temperature comming out of the roof vents goes above 70 degrees F.
Normally it comes out at 50 degrees F.
After arriving at he campground and plugging into power, the second compressor kicked on and the temperature comming out of the roof vents settled back down to 50 degrees F.
After getting back home I opened the electical box at the AC unit.Using a volt meter while the generator was running I had 117 V AC at only one of the compressor feed teminals.
Shut down and plug into AC power I had 120 V AC at both compressor feed terminals.
Any one know were I may be loosing power when the generator is running to the second compressor feed terminal.

[Yoda2405]

Check the breakers on your generator. There is a separate breaker for the 2nd compressor.
Good Luck,
David

[bigdomino]

Agree about breaker. Happened to me.

[bobpie]

Great, I thought that 20amp breaker was for that. I did check it yesterday at the same time I was checking out the electric.
That breaker was not tripped, I removed the cover and both the breakers came off with it.
I tested it after I pulled off the wires to the spade connectors using an ohm meter.
Continuity through it when in the on position, no continuity through it in the off position.
Does that mean the breaker is good? Or should I check it another way?
My Onan 5500 Emerald Gold has 2 breakers, One 30 amp, and One 20 amp. I am thinking the 20amp breaker supplies power to the 2nd air conditioning compressor
Thank you for your support and answers.

[grtharris]

bobpie, here is a link to your wiring diagram. 50 amp service is the last page.
You could have a problem in the transfer switch with the one leg from the generator.
http://www.winnebagoind.com/diagram/2001/132292.pdf

[Jbmsr]

Originally Posted by grtharris

bobpie, here is a link to your wiring diagram. 50 amp service is the last page.
You could have a problem in the transfer switch with the one leg from the generator.
http://www.winnebagoind.com/diagram/2001/132292.pdf

I second that. Turn coach battery's off unplug from shore power and disable the generator first. Test before touch. Could be a loose lug or burnt wire inside the transfer switch.
Jesse

[NeilV]

When I first got my coach the 20 amp feed from the generator to the second compressor had failed and they had to replace the transfer switch. The tech however wired it backwards and fed the 30 amp to the second compressor and the 20 amp to the main panel so I had problems throwing the breaker on the generator until I got back to them and had them switch the wires to the correct connections.

[bobpie]

Iwill take another look at the transfer switch, I did not see any thing odd with it the first time that I looked at it. I had to replace it about 4 years ago as I pulled out of the drive way with the coach still plugged in. OOPPSS. I have not had any problems since then with any electric.
I think I need to test the 20 amp breaker to see if it is operating. How?

[Jbmsr]

Switch the wires connected to the two breakers temporarily. If nothing works in the coach it is a bad breaker.

[bobpie]

OK. Hope to get out today and have a look see!

[bobpie]

After fiddling around with it this passed weekend I guess I just got lucky and the thing is working. Maybe a loose wire, just a coinsidence, I don't know.
Perhaps a bad relay or a relay that is going bad and just started to work again.

It will probably happen when it gets to 95 degrees again.

I am just a little confused on how the power gets to the AC from the generator. I thougth it went to the AC circut breaker box and then to the AC unit.

This does not seem to be the case as the 20amp breaker on the generator supplies power to the 2nd AC compressor.

My coach is 30amp power cord AC.

When plugged into power I had power at both 1st and 2nd circuts in the electrical box of the AC unit.

When running on the generator I only had power at the 1st circut and not the 2nd circut in the electrical box of the AC unit.

Now I have power at both circuts in the electrical box of the AC unit when running on generator power or plugged into 30amp power.

[grtharris]

bobpie, here is the A/C part of your wiring diagram.

[jerichorick]

bobpie could you be running a load that the energy management system is setting as priority and dumping the A/C compressor?

[Ray,IN]

Mine did that. Turned out to be a corroded connection in the A/C unit for 2nd compressor.

[bobpie]

thanks grtharris,jerichorick,Ray,IN for the info and wiring schematic.
I was not sheading any loads at the power center, and there was not any shorted wires or corroded connections in the AC electrical box.
The AC electric box does have 2 relays in it and a separate schematic for the internals.
The above drawing is what I was missing.
Where the power to the 2 circuits come from. Now I SEE. Thanks.

[jerichorick]

Originally Posted by bobpie

thanks grtharris,jerichorick,Ray,IN for the info and wiring schematic.
I was not sheading any loads at the power center, and there was not any shorted wires or corroded connections in the AC electrical box.
The AC electric box does have 2 relays in it and a separate schematic for the internals.
The above drawing is what I was missing.
Where the power to the 2 circuits come from. Now I SEE. Thanks.

Your welcome. The diagram did the trick I see. No problems. Just the way things are. Your generator size could not handle the load if not wired as it is. Bummer for you when dry docking.

[grtharris]

jerichorick bobpie will not have an issue when dry camping the generator will run both ac units. The issue is with the 30 amp service it will not run both AC units and the EMS will not shed the AC loads.
We had a early Vectra with a 30 amp service and it was wired the same way.

[jerichorick]

Originally Posted by grtharris

jerichorick bobpie will not have an issue when dry camping the generator will run both ac units. The issue is with the 30 amp service it will not run both AC units and the EMS will not shed the AC loads.
We had a early Vectra with a 30 amp service and it was wired the same way.

My error. Thanks for the correction. I'll have to trust you on this one. I have mainly dealt with 50A systems. The jumpers in the transfer sw and the service center are different. The diagram lead me to believe that ckt 2 is fed by the generator and ckt 1 by the power cord for the AC unit. If the RED breaker is fed by the 30A breaker I can see where the AC is connected on generator and ckt 2 is isolated on shore power. Not a bad design for what they were trying to do. At least the full AC is available during the heat of the day from the genset operation. When it is cooler at night the shore power should be enough, in theory that is. I don't know if that would work in the summer desert or TX.

We had a 50A service in our '05 Vectra and it could not keep up with the Dallas heat in the summer. It got down to about 97 or 98 at night. But those are extreme conditions to be planned away from. Family matters forced the issue.

Again, thanks for forcing me to take a better look.

Rick Y

[bobpie]

OK now I am a little confused?
All was good when plugged into 30amp shore power.
The trouble was when running the air off of the generator power.

[grtharris]

bobpie, Unless someone has changed the wiring at the ATS A/C compressor #2 is only connected to Circuit #2 on the generator. A/C compressor #1 is connected via a breaker to the 30 amp power cord or Circuit #1 on the generator.
What kind of amps are you pulling when connected to shore power and running the A/C?