Air conditioners when on generator power

[RMCKEE]

I have issues with running air conditioners when on generator power. I have three air conditioners that all can be controlled individually. Every time I switch to generator power and power on just one air conditioner, it trips the breaker. I have read all the manuals on the generator and the air conditioners, but does not cover this issue. Is it an issue with the air conditioners and the electric panel or is it that the generator isnt big enough to push the air conditioner.?
Thanks

[Samuel]

Need more information, do you shut everything down before you start generator or do you just switch from shore power to gen power while everything is on.The proper way is to shut everything down disconnect shore cords. Then start gen let it run for a few minutes than turn a/c pump first then turn each a/c switch on one at a time until it runs.

[bud37]

Welcome to the forum....I agree a little more info will help.....what size genny ( KW) do you have, does it run all the rest of the boat without any issues etc., there can never be too much info.

Have you had any recent work done on the gen.?

[waybomb]

Original ac unit?
In-rush current on those is phenomenal.
Could be simply that. If you have access to a amprobe with a telltale, well, it will tell the tale!

[mjk1040]

Based on the info you have supplied, it tells me that the amps being supplied to the AC panel are not enough. When your A/C unit kicks on it spikes the amps and if the amps being supplied are not up to par it will trip the breaker. If when your A/C unit kicks on while on shore power and you don not have the same issue happening, then my guess would be you generator is not putting out the amps needed to supply the A/C requirements and thus trips the breaker and most likely the main breaker. IMO!

[Viper]

If you know how to operate a volt meter, take a reading at an outlet and see what the generator is outputting with no loads on, then start turning on loads such as the water heater, stove, etc. and see if there is a dramatic voltage drop. The generator rpm should react briefly when you first turn each item on but then recover right away. Then turn off those items you just turned on and with your meter still in an outlet, turn on that air conditioner and see what happens to the reading. Low voltage will cause the load (amps) to climb and that's what trips the breaker. Other than that, the unit should not be drawing more on the genny than it does on shore power providing the voltages from both sources are the same. A weak breaker will also cause this. They have a trip threshold that may not be triggered by a more stable shore power voltage but may trip a weak breaker in the presence of low generator voltage. Other possibilities here of coarse such as generator wiring, poor connections at the source selector switch, etc.

If you have original equipment/factory setup, the generator will handle all three units operating at the same time.

[Keith S]

It is difficult to give meaningful advice without knowing the make and model of generator you have. Different models operate in different ways. It could be your rpm is too low, the governor is not responding correctly or a weak capacitor if your model uses them.

[Viper]

The Kohler 7.5R23 was a popular unit in Carvers of that Vintage. Is this the one you have?

[tomschauer]

Also, what breaker is tripping? The one on the generator, the main panel 120v , or the air conditioner breaker?

[PhilH]

Also, found our breakers do go bad without warning. Try replacing the old circuit breaker with a new one. That solved 2 of my problems.