Need help to night

[David0725]

My brother is pluged in to his generator 110/120? Outlet. Both mine and his cheap meters says he getting 130+ But he keeps blowing the breaker on the get set. Any ideas why hes getting 130 to start with and blowing breakers?

[Sam_Spade]

Sam Spade wrote:

David0725 wrote:
the only thing he had on was the A/C

There should not be ANY high draw devices ON when the generator is first started.

And are you saying that the cord going to the trailer is a "normal" household type plug ??

AND...if you have the normal situation, where the RV has a 30 amp cord and you are plugging it into a household 15 or 20 amp outlet......you should not EXPECT it to run the A/C.

The breaker is doing it's job by preventing you from overloading the outlet and possibly starting a fire.

[fourmat]

DrewE wrote:
The "110 plug" I assume means a normal 15A plug such as is used for most household devices. The socket for that on the generator would have either a 15 or (more likely) a 20A circuit breaker. The air conditioner alone comes close to that during startup, and the converter and other AC loads in the trailer add to that, so it's not too surprising that the breaker tripped. Your brother was simply trying to use more current than the socket can safely supply.

Note that a standard circuit breaker only responds to current, not to voltage. It's not even connected to both legs of the circuit, so has no way to "see" the voltage being delivered.

130V is a little high, but not really unexpectedly so for a generator with no load. The nominal domestic power supply standards (at the electric meter) are 120/240V +/- 5 percent, which works out to 114 to 126V. In some areas, at least occasional excursions outside this range are not uncommon, and most decently engineered devices are designed to work with at least a +/- 10 percent variation from nominal.

Some generators have some comparatively low-energy noise on their output that might "fool" meters when they're completely unloaded, but basically disappears with even a pretty small load. The meters aren't lying; they just respond to a high impedance noise source since their input impedance is very high. That may or many not be the case for this particular generator.

I'm guessing the generator may have a 120/240V 30A output, probably a twist-lock style. Wiring up an adapter for that which splits it into two 30A RV receptacles (or a single 50A receptacle used with the appropriate adapter) would go a long way towards solving your difficulties.

There is your answer

[Sam_Spade]

David0725 wrote:
the only thing he had on was the A/C

There should not be ANY high draw devices ON when the generator is first started.

And are you saying that the cord going to the trailer is a "normal" household type plug ??

[Bruce_Brown]

^^^ True. Good information/advice.

[DrewE]

The "110 plug" I assume means a normal 15A plug such as is used for most household devices. The socket for that on the generator would have either a 15 or (more likely) a 20A circuit breaker. The air conditioner alone comes close to that during startup, and the converter and other AC loads in the trailer add to that, so it's not too surprising that the breaker tripped. Your brother was simply trying to use more current than the socket can safely supply.

Note that a standard circuit breaker only responds to current, not to voltage. It's not even connected to both legs of the circuit, so has no way to "see" the voltage being delivered.

130V is a little high, but not really unexpectedly so for a generator with no load. The nominal domestic power supply standards (at the electric meter) are 120/240V +/- 5 percent, which works out to 114 to 126V. In some areas, at least occasional excursions outside this range are not uncommon, and most decently engineered devices are designed to work with at least a +/- 10 percent variation from nominal.

Some generators have some comparatively low-energy noise on their output that might "fool" meters when they're completely unloaded, but basically disappears with even a pretty small load. The meters aren't lying; they just respond to a high impedance noise source since their input impedance is very high. That may or many not be the case for this particular generator.

I'm guessing the generator may have a 120/240V 30A output, probably a twist-lock style. Wiring up an adapter for that which splits it into two 30A RV receptacles (or a single 50A receptacle used with the appropriate adapter) would go a long way towards solving your difficulties.

[David0725]

He is back home now But we still need to get to the bottom of what's going on. the generator is a potable one 6500 watts? He has a travel trailer with 30amp plug that he reduced to 110 plug. the only thing he had on was the A/C his water heater was running on propane. Im not sure but I think the frdge was on propane? I do think his coverter stays on all the time. thanks all of you for your help.

[rk911]

MrWizard wrote:
sounds like a portable generator ?
what brand what model ?

sounds like the voltage regulation is acting up/not set correctly
130v is a little high but not outside of limits...

but 130+ may be outside the limits.

MrWizard wrote:
...tripping the breaker is possibly something, surging (load spiking) on the higher voltage

try turning off the converter charging the batteries and make sure the fridge is on propane (manually set to lp)

some times the electric heating element becomes leaky, and will cause a GFI breaker to trip

or turn off ALL circuit breakers in the 129v electric panel
start generator
plug in
turn on only ONE circuit breaker at a time

excellent troubleshooting plan.

[nevadanick]

Amp draw is the problem, not voltage.

[wa8yxm]

Any ideas as to why the braker blows.. Yup. Mrs. Douglas (Eva Gabore on Green Acres) Syndrom.

How big is the generator< 2000 watt, 3500 watt, What breaker is trippig?
10 amnp, 20 amp, 30 amp?

What is he running inside the trailer A/C, Water heater,m Fridge, Battery charger/converter with low batteries, Electric fry pan, all of the above at once is a guaranteed click of darkness.

(On my RV that woudl be 12+13.5+11+7 amps 38.5 amps)

[Bruce_Brown]

I'll add to this if the generator is an inverter based system the over voltage may be caused because, as mentioned above, it's trying to provide enough power to do the job. An inverter type unit will match engine speed to load. If the load is too great the engine will overspeed in an effort to meet the load.

[Sam_Spade]

DSDP Don wrote:
You don't say what you're trying to power with the generator. You need to make sure that you don't have an electric water heater turned on, battery charger on coach/trailer turned on while trying to power other things.

This.

The breaker trips because of too much current draw, that is, too many things plugged it and running.

IF the breaker holds with nothing plugged in, the gen is probably OK.
Outside chance the breaker itself is bad but probably not.
I have a bad habit of forgetting to turn the A/C off when changing power sources.

You probably are drawing too much current because of too many things turned ON or because one of the devices is defective........or a fault has developed in the wiring.

[DSDP_Don]

You don't say what you're trying to power with the generator. You need to make sure that you don't have an electric water heater turned on, battery charger on coach/trailer turned on while trying to power other things.

[MrWizard]

sounds like a portable generator ?
what brand what model ?

sounds like the voltage regulation is acting up/not set correctly
130v is a little high but not outside of limits
tripping the breaker is possibly something, surging (load spiking) on the higher voltage

try turning off the converter charging the batteries and make sure the fridge is on propane (manually set to lp)

some times the electric heating element becomes leaky, and will cause a GFI breaker to trip

or turn off ALL circuit breakers in the 120v electric panel
start generator
plug in
turn on only ONE circuit breaker at a time

i hate typos..and i get them a lot..gaaah