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Topic: Failure of Onboard Generator to Provide Power-Followup (Long) (Read 8 times) previous topic - next topic
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Failure of Onboard Generator to Provide Power-Followup (Long)
Yahoo Message Number: 57476
This is a follow-up on an earlier post regarding failure of my onboard Onan generator to provide power.
The generator had had its regular monthly run under load a few days previous, and was normal. On a stop during a short trip I started the generator to run the air conditioner, but there was no 120VAC power to anything. The generator switch and all 120VAC panel breakers were cycled several times; still no power.  After getting home I plugged the line shore power back in and had full 120VAC power. I unplugged and tried the generator again: no power.
I contacted Steve Newton and with his instructions as a guide, I pulled the 120V/12V assembly out and accessed the Parallax automatic transfer switch (ATS), which is attached to the back of the Parallax Model 80 120VAV/12V housing.
For the technically uninclined, 120V current feeds into the breaker panel assembly from the generator and the line shore power through a switching mechanism. When the generator is turned on, the switch should allow a 30-60 second time delay, and then allow 120V current from the generator to flow through the breaker panel to the 120V outlets and appliances. At the same instant, the line shore power is automatically cut off to prevent both feeding into the system, and to prevent 120V current feeding back from the generator to the shore line, if attached.
I switched the lead-in wiring from the Line and Generator from the normal Line--->ATS line fitting, and Generator--->ATS generator fitting, to: Generator--->ATS line fitting, and Line--->ATS generator fitting.  After switching the lead-in wiring, I now had full normal 120VAC power when running the generator, and nothing on shore line power. This indicated that the ATS was faulty, as Michelle had correctly surmised in a previous message.
The next step was to remove and expose the ATS to check for a loose connection, loose wire, or something interfering with the relay plates. On inspection, the circuitry looked absolutely normal and I could see nothing wrong or repairable. I contacted Steve, and he had a new ATS unit UPS'd to me. When it arrived, I removed the defective ATS and did a side-by-side comparison, and still saw no obvious problem. I put the new ATS in, put all the wiring back to normal, and ran the line tests. I now had normal 120VAC on shore line, and on testing the generator  with the shore line off, there was a normal time delay, then full normal 120VAC power to all outlets and appliances. The defective ATS is being returned.

Summary: I have detailed this to help anyone who might experience a similar problem. Steve at the LD factory was most helpful for guidance and providing the replacement unit. Michelle mentioned in a previous post that it had happened to her, but in her case she lost the shore power, but still had generator power. The fault was still in the ATS.
This is the second major Parallax component failure in less than a year in my 2004 LD. I left the factory with a defective converter (the cooling fan ran constantly on 120VAC); I replaced it with a new unit sent from the LD factory, and this is still working OK. The ATS failure was without any fore-warning, and I'm just glad it didn't happen on a long trip away from home. As it was it took over ten days to resolve, and the RV coach was effectively dead in the water during much of this time, since full access to the ATS requires all electrical input be disconnected including the coach batteries and solar panel(s).

Will 2004 23.5 TK NFF  (Now Fully Functional)
Re: Failure of Onboard Generator to Provide Power-Followup (Long)
Reply #1 –
Yahoo Message Number: 57490
Will,

Thanks for the complete report to help others.  Everyone pitching
Re: Failure of Onboard Generator to Provide Power-Followup (Long)
Reply #2 –
Yahoo Message Number: 57499
Hello Will, Thanks for a nice job of summarizing the Parrallax Automatic Transfer Switch problem, analysis test and fix!  I've put a copy
Re: [Life With A Lazy Daze RV] Re: Failure of Onboard Generator to
Reply #3 –
Yahoo Message Number: 57501
Another case of trying to get too clever with the circuitry.  We had another motorhome (not an LD) and the transfer was completely manual.  Before you left you plugged the shore power line into an outlet box that came from the generator.  When you got to a site with shore power, you simply unplugged the shore power line from the generator outlet and plugged it into shore power.  Just the reverse when you left again.  It seemed in the beginning that it would have been much nicer and more convenient to have an automatic transfer switch, but when you think about it, plugging the shore power line into a socket before you travel is really not that big a deal.  And it would sure save on the problems discussed in this thread.

Dick
 
[Life With A Lazy Daze RV] Re: Failure of Onboard Generator to Prov
Reply #4 –
Yahoo Message Number: 57519
Quote from: Richard Hughes"

Another case of trying to get too clever with the circuitry.  We had another motorhome (not an LD) and the transfer was completely manual.


Richard, I couldn't agree more. We ourselves live in a storm-prone-electricity-out rural part of the Pacific Northwest, and early on I got a GenPro 9KW gasoline backup generator for the house.
The generator has been in use now for 14 years without problem.
The transfer switch for the house generator is a honking big manual unit on the basement wall next to the circuit breaker box, and when you throw the lever on that sucker you know you're in business.
Compare that with two expensive and complicated Parallax components in our Lazy Daze that have failed in the first year of ownership (despite the company's claim of 'years of trouble-free service'). I haven't heard of hardly anyone else on the forum besides Michelle relating similar component failures, so maybe I just got dealt a bad hand, so to speak.
At least the sheet metal box that holds everything together hasn't given me any trouble.

Will POAP (P______ Off At Parallax)