Generator power

[Ken Sair]

We were at the Albuquerque Balloon Fiesta in Oct. One of the days all the power shut off and the generator (Onan Q8000) went to idle. After lots of head scratching, touching, wiggling and tapping it began to work again. Fast forward to Dec 3. We spent the night in Quartzite traveling from Mesa to Palm Springs. Ran the generator for 10 hours using the A/C, heat pumps and micro wave etc. Worked flawlessly. Next morning all started well. Then, lost all power and the generator went to idle. Unable to fix. So we drove to McMahons in Indio for repair. In the lot, 100+ miles later, the generator started and ran everything perfectly. Aarrrgghhh!!

So no appointment. The symtoms were the same as the 50 amp transfer switch going out 2 years ago. So, a friend and I installed a new transfer switch. No fix, same symptoms, genny at idle, no power to coach. However, there is power going into the 50 amp transfer switch box. Strange.

An internet search produced many answers that it could be the genny voltage regulator. It is letting voltage through but not enough to make it switch over.

I'm calling Onan tomorrow. Any thought will be greatly appreciated

Ken

[Edward Buker]

Ken,

If you measure the voltage at the transfer switch when it goes to idle, is it 120V where the generator leads are and is the transfer switch not making the transfer to the coach? I think when there is no load your genset being an inverter type would go back to idle. If that is the case I would make a temporary set of jumper leads or if you can directly connect the genset leads to the leads that feed the power panel in the coach. This bypasses the relay circuit to see if everything works when there is a load presented to the generator. This is just a diagnostic to see if the circuit being used by the transfer switch company is always happy with the inverter waveform when it comes to recognizing the genset output.

When you say you have power to the transfer switch, I assume that you mean 120V from the generator. What is unknown when you have the problem, is if the generator can power the load of the coach and come back off idle. If it does then I think the problem is still in the transfer switch circuitry and I might try another brand.

later Ed

[Ken Sair]

Thanks Ed, I am calling Onan today. The switch is new and a different brand than the old one. It was just installed last monday. Different switches, same results.

Re: your first paragraph, way above my skill level. LOL

On advice from a friend I will be checking ground wires. It is intermittent after all

Ken

[Edward Buker]

Ken,

By using a different brand transfer switch you would have pretty much eliminated that being the source of the problem. As long as it is not exactly the same design/circuit board as the other one being replaced. Sometimes items today are just rebranded with another name to enlarge the market share. If that is not the case then you should feel pretty comfortable that the generator is the source of your problem. Keep us posted.

Later Ed

[Ken Sair]

Ed, two completely different designs. I ran the genny today, still no power. doing lots of reading in the trouble shooting manual. Yeesh!!

Ken

[Edward Buker]

Ken,

I think all you can hope to accomplish troubleshooting wise is to throw the generator on board breaker a few times incase it is a deteriorating contactor issue and see if you get lucky. Beyond that there is probably not a lot of things that can be done very easily on the electrical side of things that might sort this problem out.

I am not familiar with that specific generator and what the likely problem candidates might be. Sorry I do not have better news on this one.

Later Ed

[Jim Nichols]

Ken
When it happened to you in Albuquerque you had 120v at the transfer switch.  I had tapped on the three clear plastic relays in the transfer switch and you were back to normal. You have since replaced it with another and I think you said at that time it was your second switch. Now you're on a third. Could the third be goofy also? Your not tripping the gen breaker so my vote is still the transfer switch.

[Ken Sair]

Correct Jim. 3rd switch, 3 different manufactures. Breaker on the genny is not tripping. Still have 120 V at the switch but Scott said he only checked one wire. He is researching now. What are the chances of the new one being bad also? Well, its me and electricity. Very frustrating.

Genny starts, high idle for about two minutes, then drops to a low idle. Breaker in the on position. Weird.

[Jim Nichols]

What brand and model transfer system did you install?

[Ken Sair]

Its from ESCO, ES50M-65NT, in Elkhart IN. Came well recommended. I worked on it yesterday for two hours (yes I still have shore power), with Scotts instruction. There is power into the box on the genny side, there is no power coming out. So we have identified it as being a switch problem and not a generator problem. That may be the good news.

One more experiment tomorrow. It seems it is not uncommon for the switch to stick after manufacture. Tomorrow Im going to run the genny (all breakers off) and slowly switch them back on starting with the lowest, 15 amp. This may cause the switch to break free, according to internet research. See if slowly introducing power will help. Cant hurt to try.

[Jim Nichols]

Try retorqueing the screws at each incoming wire. Also the factory wiring between each relay.

[Steve Huber Co-Admin]

Ken,
Sounds like your problem is in the coil portion of the transfer relay (switch). Check the connections and source that drives the coil that activate the relay. Input and load should be OK.
BTW, do you have a Shore Guard or other input protection device installed? If so, that could be the source of your problems.
Steve

[Edward Buker]

This all seems very strange to go through 3 transfer switches and the last two have the same symptom. The other puzzling thing is tapping the relay and it suddenly works....that seems key. If the design is such that the relay coils are powered on to flip the relay switch when the shore power is applied and the coils are not powered when the genset is used then the transfer switch must be defective with sticking relays. The reasoning is that this is the resting position for the relay due to the spring loading. Mine is designed so that the relay magnetic coils are powered in the shore power position only.

The only other possibility is that circuit board is getting some marginal voltage fed somehow from the genset to the shore power side through the AC wiring, a protection device, or possibly the neutral line. You should measure the voltage between neutral and the hot lines on the shore power leads with the shore power disconnected, the genset running, and with the genset off and see if there is a voltage errantly being applied that is enough to confuse the circuit board logic into thinking it has shore power. If there is no shore power circuit board voltage being fed with the genset running then I would go for yet another transfer switch.....no guarantee but seems like the symptoms would warrant it.

Later Ed

[Ken Sair]

Jim, all wires are good, checked them twice. On the genny side there is power coming in, but no power out. Just that 'out' wire is the only one without power. Yes, I have a surge protector, but it is working properly.

Ed, we have considered the voltage regulator, if faulty and not letting in enough power to trip the transfer switch. I will try the above mentioned remedy tomorrow, spent all day today goofing off at the golf course. Ed, what you said actually makes sense to my non-electrical brain. We did that on the genny side (genny running) and thats how we found the 'dead' power line going out.

Ill know more tomorrow.

[Ken Sair]

Jim, do you recall in Albuquerque if you checked the power coming out?