Generator not Powering Roof A/C

[DutchPrairie]

2011 Tour CD. Recently, while on the road and in conditions needing supplemental cooling in the coach, the Onan 10kw QD would start the main a/c units, but then they would shut down. Now, they don’t even fire up. Power monitoring panel shows 83 amps available. Breakers not tripped on genny or for a/c units.

In northern Iowa at Camp Winnebago. Hot and humid. Shore power runs units great. Worried about getting back on the road in a few days. Thoughts on what I can do?

[Morich]

Some small details may change the answer?
Do other 110AC items also fail when the air fails running on generator?
My first thought is that the generator power and the cord power are much the same except generator has a lower limit. The limit should not be a problem but there are fairly common problems with the connections in the tranfer switch coming loose and the contact is not always good.
Click this drawing to see what shows in the transfer switch:


Basic idea is that the switch chooses cord or generator power and then sends that out to the load center. Once that choice is made, the rest is the same used for either.
So if the power fails to the air cond. on generator, it should also be bad to all other 110 AC items like microwave, outlet, etc. If those are also bad, I would suggest checking the connections inside the transfer switch for them getting somewhat loose to make or lose contact at times!

Some suggest checking and tighten these connections as a good preventive measure! The three I highlighted in blue are the three main ones to check but while there give the others a check as they may also be getting a bit loose.
One of the problems is that the soft copper of the wire can get mashed and change shape as we drive and bang them around on bumps!

Hope that may help?

[DutchPrairie]

Morich- thank you. I was unable to check other 110 VAC sources while driving. Will unhook from shore power this morning and test. Diagram and suggestions very helpful.

[DutchPrairie]

Ran gen test without shorepower. It took 2-3 mins but one by one, appliances came on. Then I switched primary a/c units on. Powered them up. Then added rear a/c unit. It all shut down with genny still running.

Onan folks here came and threw a volt meter on genset. Showing 270 vac. NO appliances receiving power. Should be 230ish. They will be helping to determine next steps.

[Morich]

It may be a technical point on how and where they are testing but it is very rare (never?) to find RV which have 220Volt systems. Use care if they are not RV folks?
Winnebago uses two 110 legs but they are the same phase and will not show 220!
Changing wiring to get 220 will likely cause a lot of trouble!

This is often a problem with folks who don't normally do RV work as it looks so much the same but is very different! I can't save they are wrong without being on scene but be aware this can be a problem isf they are not used to rV work as it looks so close it is easily confused!

[DutchPrairie]

Thanks for the concern. Well placed. It is a 120/240 unit - 2 legs. It all works off of 120. Onan folks thought controller was possibly bad ($1300 and not in stock) but turns out a wire had become unseated… re-hooking wires together properly with their respective male/female connectors solved it. I guess rough interstate roads south of Chicago strike again!

Thanks Morich.

[Morich]

All's well then! Glad to hear it works. Too hot for no Air!
I'm sometimes paranoid at the mention of 240 as it has happened that folks are close to right but rewire to use things like direr plugs which are240 and look very close to the same plug!