Main house breaker tripping in heat

[RickRox]

Folks, I'm an old (as in old fart), new RVer. Have a Thor Magnitude with 6K+ miles on it. Live in the Cali desert - Coachella Valley. It's 100 degrees out there right now. I'm trying to get the rig ready to head to higher altitudes in two days, and have been running the gen set with both AC units going to try to keep the coach as comfortable as possible while my wife cleans and stocks the inside. The main house breaker has tripped twice during the afternoon, and the gen set has shut down. The breaker will not reset at first. I'm having to restart the genny outside, and after maybe 20 or 30 minutes the main seems to reset itself, and all is good for awhile. My assumption is that this heat is overworking those AC units, and the system isn't set up for that kind of load. I'm mainly looking for confirmation of that - or, if someone has another thought, I'd be glad to hear it. Many Thanks!

[lwmcguir]

Sounds like an overheat situation

50 amp tripping?

If you're on 30 amp that would explain the house breaker but 50 amp should handle the load fine

[OldWEB]

Yeah, you are not clear which "main house breaker" is tripping and what size it is. A 50A breaker should not trip.

[RickRox]

OK - I'll try to clarify, since my description apparently didn't go far enough.
1. As stated, I'm running my gen set, so not hooked to shore power either 30 or 50.
2. The "breaker" in question is immediately to the left of the door to the coach. It's a rocker switch with a red indicator light. Turn it on and the microwave beeps and comes on, the refrigerator starts running, and the main control panel for everything else is useable. Turn it off, and nothing inside the coach will work. Maybe "main house breaker" is not the right terminology. Just learning about this stuff.

[Judge]

Originally Posted by RickRox

OK - I'll try to clarify, since my description apparently didn't go far enough.
1. As stated, I'm running my gen set, so not hooked to shore power either 30 or 50.
2. The "breaker" in question is immediately to the left of the door to the coach. It's a rocker switch with a red indicator light. Turn it on and the microwave beeps and comes on, the refrigerator starts running, and the main control panel for everything else is useable. Turn it off, and nothing inside the coach will work. Maybe "main house breaker" is not the right terminology. Just learning about this stuff.

You do have a lot to learn! Better start reading this forum and also watching as many YouTube videos as you can!!!!

I have a Magnitude so I can help you a little....

That is not a breaker you are talking about but the Main Power (12V) Switch that is also sometimes referred to the Use / Store Switch. It disconnects the house batteries from the 12V circuits when you want to store the coach for a long period of time and you don't want your house batteries to be drained.

If you are not on Shore Power or Generator Power, the red light will be on when the switch is in the "Use" position and the house batteries are able to power all of the 12V circuits such as the lights, the FireFly panel, the awning, etc. The batteries are also able to be charged by Shore or Generator Power when the switch is in the "Use" position.

When the red light is off the switch is in the "Store" position and the batteries are disconnected and most 12V circuits will not operate. The house batteries (and chassis batteries) will not be charged of you have Shore or Generator Power so keep this in mind.

Now here is the confusing part..... thanks to the way Thor wires the Main Power Light. If you have Shore or Generator Power, the red light will always be on.... even if the Main Power Switch is in the "Store" position. If the switch is in the "Store" position, the Shore / Generator power will not charge the house batteries. So make sure the red light is on before plugging into shore power or running the generator so that your house batteries will charge.

You will always have 12V power because the Converter supplies 12V under Shore / Generator power regardless of the Main Power Switch position.... even if the batteries are disconnected when the switch is in the "Store" position. So if everything goes dark when the generator shuts off, it means your Main Power Switch is in the "Store" or off position.

The Converter takes 110V and converts it to 12V to power your 12V circuits and to charge the batteries.

Now the Main Power Switch has nothing to do with the microwave (which is on 110V circuit) or any other 110V appliance. But there is another panel near the Main Power Switch that is for the Xantrex Inverter. It has an LED display along with an On / Off button and a couple other small buttons.

An Inverter takes 12V power from your house batteries and converts it to 110V power for a few circuits.... like your fridge so it can stay cool even when there isn't Shore or Generator power.... assuming your batteries are in good condition (check the water levels) and are fully charged.

When the Inverter is powered on (the On / Off button is depressed inwards), the refrigerator will get 110V power using the house batteries. Two of the TV's will also have power and one outlet in the bedroom. The microwave and other 110V outlets are not wired to the Inverter so they will not have any power unless there is Shore or Generator power available.

Now if you are pushing 100 degrees, it is very likely the generator is overheating and shutting down if running for a while. You can try leaving the door open to the generator compartment to allow more air to circulate. You should also check the oil level as well.

To keep the coach as cool as possible, you should purchase the WeatherTech Full Cab Sun Shade to cover the windshield and door windows to keep the sun out of the cab. Then pull the curtain over the cab-over bunk and close all your shades. Myself and others have posted in other threads about improvements you can make to your A/C system to help with extremely hot conditions. You may want to do a search to learn more about how to insulate the units on the roof and do some other improvements. Those 13.5K BTU A/C units are barely enough to keep up in very hot conditions since the coach is poorly insulated.

[16ACE27]

Judge provided you a lot of good info: read and heed.

I suspect you have a 500 watt generator?

That gives you 55 amps of 120 VAC power at best, less than half what you would have available if you were plugged into a 50 amp receptacle.

2 A/Cs in 100+ degree heat is sucking up 30 to 35 of those amps.
Add another 5 for the fridge
Maybe another 5 for charging and misc loads and you are working that generator pretty close to its max.

Absolutely no room left for the microwave or electric water heater.

[Judge]

The Omni / Magnitude have a QD6000 so he should be ok. The OP said he was only running the A/C units because of the heat so the DW can clean and stock the coach.

Doesn't sound like she was trying to use the Microwave and the Omni / Magnitude has the Girard Tankless water heater if she needed hot water for cleaning.

I'm betting that 100 Deg air temps plus having the generator compartment door closed was enough for it to start getting too hot when trying to support the two A/C's.

[RickRox]

Originally Posted by Judge

The Omni / Magnitude have a QD6000 so he should be ok. The OP said he was only running the A/C units because of the heat so the DW can clean and stock the coach.

Doesn't sound like she was trying to use the Microwave and the Omni / Magnitude has the Girard Tankless water heater if she needed hot water for cleaning.

I'm betting that 100 Deg air temps plus having the generator compartment door closed was enough for it to start getting too hot when trying to support the two A/C's.

Thanks to all for pitching in to help. Judge, your detailed description of how Thor sets these things up was particularly helpful. Some of that was a bit different from what the salesman told me, but that was really not much of a surprise, as I've had to go back and educate him about a few other things he got wrong. And --- he's the guy who gives the orientation walk-through to all of their new customers.

Anyhow, I've come away with some good information. I'm not quite as green as I perhaps sounded, as I've been a boater for 25 years, and some of these systems are familiar. However, although I'm not hesitant to tackle changing out a water pump down in the engine room, electricity still seems a bit like hocus-pocus, so I'm cautious around it. I've had generator problems in the past, but mostly related to a lack of flow from a raw water intake strainer or pump. The only time I've run into generator overload, resetting the breaker on the unit took care of the problem right away.

The thing about yesterday that I've never run into before was that main power switch - the one I mistakenly called a breaker. When the gen set quit, the Xantrex panel LED indicated that I still had battery power, but the red light on the power switch was off, and the switch would not respond. Everything in the coach was dead, including the touch-screen control panel which was black. After a bit, I started the generator with the start switch down in the compartment, and maybe 10 minutes later, everything came back on, including the red light on the power switch, without me touching it. Like I said - it's a bit of hocus-pocus to me.

Thank again everyone!

[Judge]

Originally Posted by RickRox

Thanks to all for pitching in to help. Judge, your detailed description of how Thor sets these things up was particularly helpful. Some of that was a bit different from what the salesman told me, but that was really not much of a surprise, as I've had to go back and educate him about a few other things he got wrong. And --- he's the guy who gives the orientation walk-through to all of their new customers.

Anyhow, I've come away with some good information. I'm not quite as green as I perhaps sounded, as I've been a boater for 25 years, and some of these systems are familiar. However, although I'm not hesitant to tackle changing out a water pump down in the engine room, electricity still seems a bit like hocus-pocus, so I'm cautious around it. I've had generator problems in the past, but mostly related to a lack of flow from a raw water intake strainer or pump. The only time I've run into generator overload, resetting the breaker on the unit took care of the problem right away.

The thing about yesterday that I've never run into before was that main power switch - the one I mistakenly called a breaker. When the gen set quit, the Xantrex panel LED indicated that I still had battery power, but the red light on the power switch was off, and the switch would not respond. Everything in the coach was dead, including the touch-screen control panel which was black. After a bit, I started the generator with the start switch down in the compartment, and maybe 10 minutes later, everything came back on, including the red light on the power switch, without me touching it. Like I said - it's a bit of hocus-pocus to me.

Thank again everyone!

So as I mentioned… the Main Power (Use / Store) Switch controls the 12V systems…. but not all 12V systems. It does not control the Inverter.

Your Inverter is wired directly to the house batteries because of the amount of power it can draw. It also is independent so you don’t cut power to the fridge should you have food in it and you accidentally mive the Main Power Switch to Store/Off.

If the Inverter is powered on, the display will always read the house battery voltage regardless of whether the Main Power Switch is in the Use (red light on when not on shore or generator power) or in Store (red light off when not on shore or generator power).

Hopefully that clears up some of the hocus pocus.

Since you are a boater, you should go to the Thor Owners Site and download the schematics for your coach. One document contains the 12V, 110V, plumbing and construction schematics. It may help you better understand what Thor has done…. which is noy always best practice or the same as a boat, house or car.

[Connieb]

Originally Posted by RickRox

OK - I'll try to clarify, since my description apparently didn't go far enough.
1. As stated, I'm running my gen set, so not hooked to shore power either 30 or 50.
2. The "breaker" in question is immediately to the left of the door to the coach. It's a rocker switch with a red indicator light. Turn it on and the microwave beeps and comes on, the refrigerator starts running, and the main control panel for everything else is useable. Turn it off, and nothing inside the coach will work. Maybe "main house breaker" is not the right terminology. Just learning about this stuff.

Sounds like the battery switch to me