Open Neutral

[Retired and Happy]

Last April we stayed at the Chattahoochie (FL) KOA for about an hour when they had no power due to a thunderstorm. Since we had medial equipment to run, we moved on. Last week we gave them another chance. This time WE were the ones without power. At least we didn't have 30 amp power from our generator when we checked out. Again we moved on, this time without any power except to the rear air conditioner. At our next stop in Mobile I spent too much time testing the wiring around the transfer switch. After many rewirings I finally used my $3.99 line tester and found an open neutral in the 30 amp circuit. I am assuming there are many places this open could take place, from the transfer switch back to the windings in the generator. Any hints on how to narrow it down, or is this a problem for the Cummins-Onan tech?

[EngineerMike]

If you are not very familiar w/110V wiring, leave this to qualified help. An open neutral is a dangerous situation, as you will get feedback thru the coach's internal neutral wiring, thru the neutral bus and be feeding 2 live legs (maybe same phase if onboard power, or maybe 220V total if pedestal power to a variety of appliances that won't like it (fridge for instance, TV for instance), and worst case you'll have a neutral connection to frame that can be downright lethal.

I would test the pedestal alone & if open neutral there- go to another site.
If pedestal is good & open neutral is in coach, you'll need a qualified tech to start at one end and check all neutral connections (xfer switch(es), 110V panel, etc.).

[Retired and Happy]

Maybe I wasn't as descriptive as I could have been. The open neutral was with a pigtail attached to the generator 30 A output after i had removed the generator wiring from the ATS. Everything is fine with shore connections, whether wired through the ATS or not. It's just the generator output that is a problem, and then only the 30 amp side. The 20 Amp side seems to be ok.

[Gary RVRoamer]

Sounds to me like a job for an Onan tech.

[J Walker]

You could look for an in line fuse on your generator that might have blown.

[Retired and Happy]

Using Google, I see many requests for Onan generator wiring diagrams, but I haven't seen any replies with the information. Do you know of a source for wiring info? 6.5 kw. I'd like to at least look for obvious possibilities for the open neutral, even though I suspect it is in the generator itself.