Generator runs fine, but no electricity in coach

[Janss]

We were parked at a casino overnight. Generator and electricity worked fine in the evening. Next morning, electricity stopped midstream as the coffee was filling the cup. But generator was still running. Shore power works, as our next several days were in RV parks.

No circuit breakers appeared to have flipped off, but after this happened, I purposely flipped them all off and then on again....on the generator and every breaker inside the coach. Aux batteries are good. One had a slightly loose negative cable. Tightened that, but still didn't fix the problem.

This coach has an automatic transfer switch box in the electric storage bay. Didn't see anything loose in there. Nothing felt hot.

Any ideas?

[bounder39zman]

If this model of Onan continues to run, then it is making power. Assuming circuit breakers are on (and good), then most likely problem is wiring connections in connection box (usually near genset itself), or in transfer switch. I've found most transfer switch problems to be in the time-delay circuit board in x-fer sw. It can often be by-passed with a small dip switch on circuit board. (The switch will engage on generator power, but no time delay)

[Bobbo]

Janss wrote:
Bobbo...I wouldn't know where to plug that tester in. My generator and shore power are hardwired to the automatic transfer box.

Sorry about that. I thought it was a portable generator. If you can get to the wires going from the generator to the ATS, you can use a Non Contact Voltage Tester. Touching the tip to the insulation over the hot wire makes it light up/beep. Touching the tip to the neutral or ground wire does not. If you can get to the wire, touch the tip to all sides of the wire.

[Janss]

It'll be a few days until I can work on this again. So I may be back. I appreciate all the original and additional information.

I will flip the generator and in coach circuit breakers off and on again, even though I had already done that to begin with.

No pacemakers here, but thanks for the warning.

Bobbo...I wouldn't know where to plug that tester in. My generator and shore power are hardwired to the automatic transfer box.

I know that there is no power inside the coach. The power management panel is not indicating that generator power is coming in while the gennie is running. I need to determine if the generator is not producing power or the automatic transfer switch is not working. I do not know exactly how to check these things. I may end up hiring an RV tech or electrician.

[Bobbo]

A cheap 3 light tester will tell you if the generator is putting out power, no knowledge needed. Just plug it in. If you have a bonded neutral, then two lights should light up. If you have a floating neutral, then one, and only one, light should light up. Both of those are normal results and show the generator is putting out power. (A floating neutral is reported by this device as an "OPEN GROUND.")

[MEXICOWANDERER]

I can hope there is a responsible You Tube tutorial about how to use your meter. Do not guess.

Also, I highly recommend using nitrile mechanic's gloves when working around live circuits. They will protect against 120vac shock if dry.

Also folks with Pacemakers should not work on generators. The reality is not a failure of the Pacemaker. It's vulnerability is corrupted memory that can erroneously show fibrillation, Bradycardia, or even Infarction when your cardiologist retrieves data.

[bgum]

RESETTING CIRCUIT BREAKERS
If a circuit breaker in the main power distribution
panel of the vehicle or on the genset (Figure 7) trips,
either a circuit shorted or too many appliances were
running. Note that the genset may continue to run
after a circuit breaker trips.
If a circuit breaker trips, disconnect or turn off as
many loads as possible and reset the circuit
breaker. (Push the circuit breaker to OFF to reset it
and then to ON to reconnect the circuit.) If the circuit
breaker trips right away, either the electrical dis-
tribution system has a short circuit or the circuit
breaker is faulty. Call a qualified electrician.
If the circuit breaker does not trip, reconnect the ap-
pliances, one by one, up to a total load that does not
overload the genset or cause the circuit breaker to
trip. If a circuit breaker trips right away when an ap-
pliance is connected, the appliance probably has a
short.
Electrical appliances and tools must be used and
maintained properly and be properly grounded to
cause the line circuit breakers to trip when short cir-
cuits occur.
WARNING Short circuits in electrical
appliances and tools can cause fire and electri-
cal shock leading to severe personal injury or
death. Read and follow the equipment and tool
manufacturer’s instructions and warnings
regarding use, maintenance and proper
grounding.
CONNECTING UTILITY POWER
A vehicle with provisions for connecting utility power
must have an approved device to keep the genset
and utility from being interconnected. See the gen-
set Installation Manual for more information.
WARNING Interconnecting the genset and the
public utility (or any other power source) can
lead to electrocution of utility line workers,
equipment damage and fire. Use an approved
switching device to prevent interconnections.
LINE CIRCUIT

Straight from the manual.

There appears to be two reset switches next to each other on the genny.

[Janss]

Thank you all for your responses.

bgum...Onan 5500 Marquis Gold

schlep1967...Had already pushed GFI several times, black and red, with no clicking. If shore power is powering everything, should I assume no problem with GFI?

wolfe10...I had already done that.

BB TX...I don't see a reset button.

Yes, I totally agree that I need to isolate exactly which step is not putting out power. But I don't know how to do that and realize there is a safety issue. I have a multimeter (which I set on "Volts"), but don't know exactly where to touch the red and black probes. And with or without gennie running? I see on the generator a positive terminal and also the word "ground" on a piece of metal. I had opened the transfer box and touched the probes on screws holding wires in place (without gennie running), but no reading.

I sure don't know much about electricity, so need baby step instructions 🙂

[schlep1967]

Did you check the GFI outlet in the kitchen or bathroom?

[bgum]

You are running what brand name and model genny?

[wing_zealot]

You need to limit the choices by starting at the source and moving forward. First check if gen is outputting 120 volt, if yes is there 120 incoming from gen at transfer switch, if yes, is there 120 output at transfer switch - and keep going down the line until you isolate the culprit. As it is now, you’re just throwing darts with a blindfold on.

[wolfe10]

Yes, turn OFF and back ON the breakers on the generator itself.

[BB_TX]

Generator was running but did you verify it was actually putting out power? Some generators have an overload reset pushbutton that must be pushed in addition to breakers.

[CA_Traveler]

Also a good idea to check, clean and tighten DC and AC connections. RVs vibrate and bounce down the road and connections become loose. Unplug, solar off, gen off, batteries disconnected. Again safety as a battery short can get very hot in an instant.

[CA_Traveler]

CBs can be deceptive - push them fully off then on. Check inverter CBs also as some pass through 120V.

Next I would unplug shore power and measure AC in and out of transfer switch with the gen running to isolate the problem. BUT don't do this unless you fully understand the danger involved and related safety.