AC and convection microwave on same breaker ?

[Crazycanucks]

To start with I have little knowledge of electrical systems or generators .

We were in Dover DE this past week and in need of our AC. Started our champion dual fuel generator ( tested at home in May , worked fine with AC for an hour before I turned it off )
After attaching the cord to our AS the generator sounded stressed like it was taking on a load , nothing was on except for the water pump, the microwave power comes on when we attach the cord, turned the dometic on to cool setting , after 15secs or so the AC turned on and then overpowered the generator and sent an E7 message to the domestic control panel.
I did get it to work twice by turning the breaker off then plugging in the generator , then flipping the breaker on again .
Figured out both AC and micro are on the same breaker. We never use the micro (invection)anyway and was wondering if the microwave is hard wired or plugged in behind ?
I know champion is not the generator of choice in these forums , but at 3400 it should have no issues keeping A 15k AC unit running on a 2016 - 26U.

[Bobbo]

Were your batteries low causing the converter to pull a lot of current?
Was your water heater on electric pulling a lot of current?
Was your refrigerator on electric pulling a lot of current?

Except for the converter, which you can't help, everything else should be on propane only if you are powering by generator.

I doubt if the convection microwave affected it at all unless you were cooking with it. Just powering the display takes almost no current.

[Crazycanucks]

Water heater was off , fridge on propane ( no shore power on this trip) , battery was at 12.2 ..... too low ?
Just seems weird that as soon as I plug in to AS the generator surges for a few secs .... does the converter draw that much power ?

[Crazycanucks]

Originally Posted by Bobbo

Were your batteries low causing the converter to pull a lot of current?
Was your water heater on electric pulling a lot of current?
Was your refrigerator on electric pulling a lot of current?

Except for the converter, which you can't help, everything else should be on propane only if you are powering by generator.

I doubt if the convection microwave affected it at all unless you were cooking with it. Just powering the display takes almost no current.

Water heater was off , fridge on propane ( no shore power on this trip) , battery was at 12.2 ..... too low ?
Just seems weird that as soon as I plug in to AS the generator surges for a few secs .... does the converter draw that much power ?

[Bobbo]

At 12.2v, the battery was low, but the converter does not draw a HUGE amount of power. A 55 amp converter is 55 amps of 12v DC which only comes to 6 or 7 amps AC. Your A/C should draw around 13 to 15 amps (more at startup). If those were your only 2 big draws, you SHOULD be good.

Rack your brain. Was there ANYTHING else on AC power?

I know you said the water heater was off, but it is such a power hog that you should double check that it really WAS off.

Here is a chart to help you with battery SOC (State Of Charge). You never want to get below 50% SOC.

[RonaldC303]

If the refrigerator was set to AUTO, it would have switched to AC when it became available. I haven't measured what a converter will draw when at max charge rate but I can imagine at least 6A. Those two items may have been just enough to overload the generator. Maybe not. Just speculating.

Easy to test. Turn off the circuit breaker for the converter. Make sure the frig is set to LP.

Ron

[Crazycanucks]

Originally Posted by RonaldC303

If the refrigerator was set to AUTO, it would have switched to AC when it became available. I haven't measured what a converter will draw when at max charge rate but I can imagine at least 6A. Those two items may have been just enough to overload the generator. Maybe not. Just speculating.



Easy to test. Turn off the circuit breaker for the converter. Make sure the frig is set to LP.



Ron

Thanks
Was definitely set to auto not solely LP

[Bobbo]

Originally Posted by Crazycanucks

Thanks
Was definitely set to auto not solely LP

That might just have been enough to do what you experienced. When on generator make sure EVERYTHING that can be set to propane only is set to propane only.

Originally Posted by RonaldC303

If the refrigerator was set to AUTO, it would have switched to AC when it became available.

Nice catch!

[cwf]

Folks... seems to me there is a need for clarification..

For electrical power,
AC : Alternating Current (household electrical power) 110-120 volts, alternating 60 cycles in the US.
DC : Direct Current (typically battery) or solar, or converter, 12 VOLTS, direct positive to negative.

Converters take AC to make DC. No AC...no DC.

Inverters take DC to make AC. No DC no AC

Converter may charge batteries AND provide sufficient power for
DC items. If batteries at low voltage, they may draw more than the converter supplies. If batteries are bad, converter may be overwhelmed and not provide adequate DC needs.

AC powers the appliances, WH, AC, Mw, converter.

However.. regarding appliances, DC provides "control power" to the appliances... 12VDC (Volts Direct Current) to the fridge, AC thermostat, WH and furnace. The DC is used to power the appliance logic and LP control valves. On our Furnace, the fan is DC also...

The DC from batteries with no AC power available will not run anything except lights, DC fans, water pump, logic and thermostat, LP valves.

When on AC, the converter will provide DC only.. that and sometimes the batteries provide all DC power.

To wrap up your problem to diagnose..
- all appliances MUST be OFF... with exception of the AC...
- the Mw probably doesn't oull enough in standby to drag system down. But I am surprised if they are on same AC circuit breaker(breaker). Usually there is a Galley and bath breaker then separate AC. The Mw is likely plugged in... just remove it to disconnect. (If there is no proper load balancing)
- the AC (air conditioner) MUST have DC to power it's controls.. any DC load with poor batteries may not reliably power the thermostat.. that means AC would not be controlled reliably. And you may get erratic performance and get something like start stop start stop etc.
- remove batteries carefully and get them Load tested. If below 80% consider replacing both
- BTW.. you Must have Good batteries to properly activate trailer brakes in the event of accidental separation from the Tow Vehicle.. I think it is actually the LAW for certain weight trailers.. check your state

Now, fresh batteries/ proper charge, all loads turned OFF except AC..
- start generator.. wait till warmed up
- switch ON the AC via thermostat

Does it work properly?

[The Colonel]

Sounds like op already said what problem was, refrigerator was set to auto.

[Toasterlife]

Our 23 ft rear bed CD is about 7 years old. The microwave and AC are on the same circuit. Even on shore power if the second motor comes on they immediately trip the breaker. It has been like this from the start. We just have learnt to use them one at a time. One of the poorly thought out design issues we have come up against over time.
The worst feature in my estimation is that it is impossible to heat the trailer while boondocking as the furnace is an absolute power hog - so unless you have shore power or a generator there is no way to keep the trailer warm even for 1 night at cool (not below freezing) temperatures without trashing the batteries.

[lsbrodsky]

I have a lot of bad things to say about AS implementation, but not many about concept. I am not sure how you think the trailer should be heated when boondocking; down comforters work best for us. I am sure you could find a safe catalytic propane heater, but the forced air propane furnace is a good way to get the whole trailer toasty. As for the breakers, we have a practice of simply not running more than one major AC appliance. I consider that a shortcoming of 30 amp that is easily worked around. Wouldn't be a problem with 50 amp, most likely, but then you have that big cord.
Larry