Breaker #8 tripping.

Topic: Breaker #8 tripping. (Read 903 times) previous topic - next topic

Breaker #8 tripping.

September 18, 2016, 11:03:27 am

So here we are in Houston, 86 deg, sunny 84% humidity, both A/C units running, TV, Sat receiver, AH 110 vac and res refer. Wife plugs hair dryer in and trips breaker #8 - Magnum Inverter/Converter. I am thinking we are overloading system or........?

Re: Breaker #8 tripping.

Reply #1 – September 18, 2016, 11:19:01 am

What else do you have running on an inverter-wired circuit (including amps used for battery charging)?

If you have inverter output wired to a sub-panel (best way), start by turning off all breakers on the sub panel. If breaker still trips, it is a problem in wires from main breaker box to inverter/charger, a problem in the inverter/charger or a problem in the wires from inverter charger to sub-panel.

If breaker does not trip, start turning on the breakers on the sub panel one at a time to locate the culprit. Again, the culprit could just be too many smaller loads on at the same time.

If battery charging is drawing high amps, most inverter/chargers have a "power share/power save" feature so that you can limit the amps of 120 VAC used for charging. Of course, amp draw should be very low once you are plugged in long enough to reach float.

Understand the "heat and humidity". We are 25 miles south of you in League City.

Re: Breaker #8 tripping.

Reply #2 – September 18, 2016, 11:22:55 am

Scott, you have the MS2812, right?

Re: Breaker #8 tripping.

Reply #3 – September 18, 2016, 12:10:50 pm

Brett - Thanx. Am away from the coach for the day. Will go through the process you listed tomorrow am.

Chuck - Yes, 2812.

Re: Breaker #8 tripping.

Reply #4 – September 18, 2016, 01:39:24 pm

Quote from: Carol & Scott – September 18, 2016, 12:10:50 pm

Yes, 2812.

Not sure how your inverter is wired up...I asked the tech that installed our 2812 what would happen if I "over-loaded" it. I was, at the time, discussing with him the possibility of trying to run the front roof air on inverter. (Have since abandoned that idea) ANYWAY, he said "overloading" the inverter is a non-problem, because it would automatically kick off to protect itself before any damage could happen. This "auto shutdown" has occurred several times since, just as predicted. We have had the coach is parked in our driveway, running the roof air units on shore power, and had the grid power go down due to local thunder storms. Sequence of events: grid power fails, inverter automatically takes up the coach load, front roof air conditioner compressor tries to start, inverter kicks off line. No damage is done, and no panel circuit breakers open. I shut off air conditioners, turn inverter back on, everything happy.

So, if "overloading" is causing your problem, I'm wondering why your #8 circuit breaker opened before the inverter shut down. I would think the breaker on the inverter circuit would be sized to handle the max inverter load + a little bit. so that the inverter would always shut down before the circuit breaker opens.

But I could be completely off base in this thinking!

Re: Breaker #8 tripping.

Reply #5 – September 18, 2016, 01:51:10 pm

Chuck - How many amps on you #8, if that is where your inverter is?

Re: Breaker #8 tripping.

Reply #6 – September 18, 2016, 01:59:03 pm

I do not think my inverter is wired to even power my AC units and we always shut off the ac before running the hair dryer. They take a bunch of power. Also check and see if your AH is on on electric. It is something we usually forget. I know I have three AC units on at times and I have to be careful.

Re: Breaker #8 tripping.

Reply #7 – September 18, 2016, 02:02:02 pm

Our a/c units are not wired through the inverter.

Our AH was on as well as TV, cable box, both a/cs, lights, ceiling fan and hair dryer.

Re: Breaker #8 tripping.

Reply #8 – September 18, 2016, 02:02:31 pm

Yup, apples and oranges.

Foretravel never wired inverter output to supply whole house.

Yes, some owners did wire them that way-- not my choice. Wiring inverter output through a sub-panel is the cleanest, most idiot-proof way to do it.

Re: Breaker #8 tripping.

Reply #9 – September 18, 2016, 02:06:58 pm

Brett - That's how ours is. Secondary panel.

Re: Breaker #8 tripping.

Reply #10 – September 18, 2016, 02:41:07 pm

While you guys were chatting, I had to run out to the coach to take some photos. Shown below is the original main AC panel at foot of bed, with changes made by AM Solar. Raising up the bed platform, we see the inverter sub panel, with labels.

So to answer Scott's question, apparently my inverter is protected by a 50 amp breaker on the main panel, and a 50 amp on the sub-panel..

To address John S's query, I specifically asked AM Solar to include the front air conditioner on the inverter panel, because I wanted to play with trying to run it off the inverter. Turns out the "start-up" surge of the compressor is too much for the inverter, and it kicks off. I can, however, use the "fan" setting on the front A/C unit when running on inverter. We have used this successfully for increased air circulation in the front of the coach when driving down the highway. Of course, if we want cold air, then I must start the generator.

I also had them add the bedroom duplex outlets to the inverter, so we could power our electric blanket off battery.

Re: Breaker #8 tripping.

Reply #11 – September 18, 2016, 02:59:59 pm

Quote from: Carol & Scott – September 18, 2016, 02:02:02 pm

Our a/c units are not wired through the inverter.

Our AH was on as well as TV, cable box, both a/cs, lights, ceiling fan and hair dryer.

You AH is like another AC unit if it kick in and will use about 15 amps. The ac and Ah and everything is probably on that one breaker and you overloaded it or it is weak and it was close to being overloaded. You can't really run a hair dryer AH and AC and Fridge all on the same circuit I would think. We turn off the AC or the AH prior to using a Hair Dryer. They pull a lot of amps for as long as they are on.

Re: Breaker #8 tripping.

Reply #12 – September 18, 2016, 08:15:38 pm

Another possibility is just that the breaker is old. We replaced a couple in the main box over the years due to age - they would trip due to vibration going down the road. Coincidentally the ones at the bottom of the breaker panel, closest to the heat of the engine. Replacements are available at Lowes.

Re: Breaker #8 tripping.

Reply #13 – September 18, 2016, 08:23:16 pm

Pic of Panel identification:

20 Amp GE fuse. Will replace tomorrow.

Have been gone all afternoon and everything is A-OK.

Thanks all.

Re: Breaker #8 tripping.

Reply #14 – September 18, 2016, 09:03:18 pm

Doesn't make sense to my pea brain. Will pull drawings tomorrow and attempt to understand what comes from where and where it goes.

What panel/breakers powers outlets? Seems like many breakers power many outlets?

Pics of Breaker Panels -

Re: Breaker #8 tripping.

Reply #15 – September 18, 2016, 09:09:57 pm

Are the pictures of the sub-panel??? If so, am very surprised to see A/C, block heater, etc. Suspect that is the main panel.

Yes, whether in an RV or house, very common for one breaker to power multiple outlets and devices.

Re: Breaker #8 tripping.

Reply #16 – September 18, 2016, 09:20:03 pm

Yes Brett - 2 sub panels.

The subpanel on the left is powered by the Gen Set/Shore Power and Inverter/converter. and appears to flow power to the breaker on the right. It is Breaker #8 on this panel that has tripped.

The subpanel on the right has a Large Gray wire loom going through the floor - I would guess to the inverter converter.

Re: Breaker #8 tripping.

Reply #17 – September 19, 2016, 06:56:06 am

Second photo (with more breakers) is your main box.

First photo (with less breakers) is your sub panel - those are the circuits which should be on the inverter power.

Here are schematics for a 2003 U320. You can see there is a hot feed from the main box (connected to one leg of the AC mains) as one input and the Inverter as the second input into the transfer switch which then feeds the main of the subpanel.

Breaker 8 is the power to the converter/charger side of the inverter. If that breaker is tripping either the Magnum is pulling too many amps to try and charge the batteries OR something else is wired into that circuit that you don't know about. Or the breaker is just weak.

Re: Breaker #8 tripping.

Reply #18 – September 19, 2016, 09:00:33 am

Thanks Michelle.

Re: Breaker #8 tripping.

Reply #19 – September 19, 2016, 09:51:33 am

#8 tripped for me when transfer switch #2 failed. At that point everything on the inverter subpanel was powered by the 20 amp #8 circuit.. Way easy to overload.

Re: Breaker #8 tripping.

Reply #20 – September 19, 2016, 09:58:38 am

Replace the CB. Those skinny GE breakers have a limited life expectancy. When they start tripping for no apparent reason, replace them.

Re: Breaker #8 tripping.

Reply #21 – September 27, 2016, 12:18:53 pm

Replaced the breaker today. Have had no recurrence since original post. After I replaced the breaker the Magnum ARC50 showed "Absorption charge" where as before the change showed "float". Thanks. 😊

Re: Breaker #8 tripping.

Reply #22 – September 27, 2016, 04:35:14 pm

OK.Scott are you storing milk or hanging meat in your salon? Do you really have three ACs in a 36 foot coach?

Re: Breaker #8 tripping.

Reply #23 – September 27, 2016, 08:09:11 pm

Quote from: Michelle – September 19, 2016, 06:56:06 am

Here are schematics for a 2003 U320.

Valuable wiring diagram. Do you have similar you can post for the 12 volt side? (especially which breaker does what?)

[fixed quote - Michelle]

Re: Breaker #8 tripping.

Reply #24 – September 27, 2016, 08:20:01 pm

Quote from: AC7880 – September 27, 2016, 08:09:11 pm

Valuable wiring diagram. Do you have similar you can post for the 12 volt side? (especially which breaker does what?)

We do have them, but they are HUGE files (100 MB and 29 MB) since Steve scanned them at very high resolution and the forum won't support that large a file.

There's also more for the 120 Vac system, it's 3.7 MB file total.

FT includes hard copy of these schematics in the Owner's Manual for a coach. We scanned ours into a PDF. Bill Chaplin had a great idea to take his to Kinko's/Staples/etc., get them enlarged and laminated.

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