Can't run both AC's in Texas

Am going to buy a voltage meter ASAP. Also what is a voltage booster and do I need one

We experienced not being able to even run 1 AC and the frig at the same time at a campground where the voltage was dropping to low when it was hot and crowded and everyone had their air on. This was in MI when it was in the 90's. We purchased a voltage booster to get thru the rest of the summer. We have now used it more than once and are glad we purchased it. With that we were able to use our 50 amp rig like you are supposed to be able to. Also helps when we have to hookup to 30 amp.

Here is another nice drawing that may help you in measuring the 120VAC associated with the 50AMP connector...



Roy Ken

If you still have issues. Make sure the breaker panel in the RV is not blocked by a closed closet door. If it is,open it and get a fan going on the front of the panel to get the breakers cooled off. Inside the panel is the EMS load shedding circuit board and the AC breakers themselves lose capacity with heavy heat loads. I recently had this issue after 5 years of use. Seemed a bit strange. I placed 1/8 inch spacers behind the screws to hold the face plate out a tiny bit. Runs much cooler now.

OK, good, you are cooling off with generator powering both A/C's.

That tells us that your 120 VAC system from ATS(Automatic Transfer Box) onward is OK, since both generator and shore power share exactly the same wiring and connections from the ATS coach-ward. Also, that the converter that charges your batteries is LIKELY OK, since everything works now-- both 120 VAC and 12 VDC.

SO, the problem is either in the CG side of things, your cord or your cord's connection to the ATS.

With a voltmeter (your own or borrow one-- almost everyone carries one):

If you don't have a voltmeter or are uncomfortable working with 120 VAC power, I am positive that someone else in the CG would be happy to help. Go to the CG outlet:

From either outer straight (hot) to center straight (neutral) or center round= 120 VAC.

From center straight to center round= 0 VAC

From outer straight to outer straight= 240 VAC

If that is as it should be, continue:

Look closely at the plug end that you plug into the CG outlet. Any sign of overheating? Pitted or off color metal or is it nice, clean copper. If not overheated, but copper not bright and shiny, you can use fine sand paper to "dress it".

At the coach end of the shore power cord, you need to check that all connections are clean and tight. DO THIS ONLY, REPEAT ONLY WITH GENERATOR OFF, SHORE POWER DISCONNECTED AND INVERTER TURNED OFF.

You/have someone else open the ATS and check the connections there.

Follow what Brett asked about.
Go to your RIG main circuit breaker panel. Disconnect the dual main breaker.
Verify that the air conditioner thermostat is turned off.
Turn on generator, wait a few minutes.
Turn on main (Rig breaker) then turn on air conditioner.
What happens?

Start with this first.

You asked about weak converters. 40 ft rigs on 50amps normally have an inverter/charger. Next with 50 amps, your rig is capable of running both air conditioners, microwave and the water heater (electric).

If you do not have an energy management system (EMS), then it is possible you have a bad automatic transfer switch (ATS).

To trouble shoot from a distance, you will need to record exactly what is happening and when, otherwise all we can do is guess.

120VAC AC coming from your generator set is no difference than coming from the shore power connection. Only the 120VAC level may be different. You may also have a surge protector plugged in on the shore power side which may need reset or replaced. You will have a AC transfer switch also that selects either the 120VAC coming from the shore power connection or the generator. That may be bad as well...

Those are the only things I can think of that might be in your 120VAC circuit. We all thought for sure you was using the 50A to 30A adapter which is known to give symptoms like you was describing but you have rulled that out now... This is why everyone was asking twice about that.

Sometimes the GFCI breakers get tripped and cause strange thing to not work. You should have about three of those in the trailer usually where you might have a water source.. Kitchen Sink, Shower, and wash up area around the bedroom. Might check and see if one of those may needs reset.

I'm just plugging away here. Have never set foot inside a motorhome before haha.. Most everything is the same whether it is a RV trailer or motorhome...

Roy Ken

Everyone should carry one of these small inexpensive mulitimeters from WALMART/LOWES Only cost $7-$20 and will read both your 120VAC circuits as well as your battery circuits.



I also use one of these RV 120VAC plug-in meters. It has the safe "GREEN SCALE" printed on the face. If the 120VAC is not within this safe zone then I dont turn on my air conditioners... I got mine from AMAZON.



Roy Ken

Sorry for the confusion guys... I was plugged into a 50 amp box shore side. I only got small amt of power, only 1 ac would run at a time with some plugs using small fans. If I am plugged into shore everything shuts off when hot and turning on 2nd ac. Or sometimes just a light. Forget about the microwave.

I have done as Wolfe 10 suggested and unplugged from shore turned on generator. I am now running both AC's drawing between 20 and 19 amps according. To load meter panel.

What kind of meter do I need to buy to check the voltage?

What do I need to tell the service people in Abilene Monday I need them to check?

If I can fix this it would be much better for me

Rayburn - great there was some confusion on here which one you was connected to. You are plugged straight into the four prong 50AMP plug i.e. not using an adapter and plugged into the 30AMP connector.

If you was plugged into the 30AMP side then that would answer some of your 120VAC problems.

You mentioned the converter awhile ago.. The converter run from 120VAC and produces 12VDC which replaces the battery when you are connected to shore power. It also charges your battery when you are on shore power. Should not have anything to do with being week and affecting your 120VAC issues.

If the converter AND the battery was not working or connected to the 12VDC side of the Power Distribution Panel it could kill your air conditioner thermostat which is operated from 12VDC. I dont have a 50AMP power distribution flow diagram here but this is a 30AMP electrical layout - maybe this help understand what is connected to what...


Roy Ken