Electrical Problems

[GDGorsuch]

Faulty main breaker? A bit long--sorry. On our last trip in Sept, very warm but no issues w/AC except the main breaker tripped several times.

The coach went into the RV shop for some body work--I asked them to check the breaker problem. Their diagnosis was rear AC pulling too many amps during start up tripping the breaker. When trying to learn why AC was pulling too many amps they could not duplicate the problem. AC started/ran fine, no breaker tripping. OK, will watch it...

On another trip now, breaker issue worse plus other problems. It's in the 40's here at night, warm days--trying to use heat pump at night, AC days--neither work front or rear units.

Since I could not get the AC units to work i shut off the breaker to the front and the rear AC. Even with these breakers off, last night the main breaker tripped off three times. Almost no load, no tv, just a couple lights.

The breaker for the front AC when turned to ON makes a clicking noise. Sometimes just for 4-5 clicks, sometimes clicking until I turn it off.

The hot water heater has stopped working on 120V--does work on 12V propane.

The first night, when I was trying to get the heat pump to work I saw the amp meter register 61 briefly and my Hughes 50 amp surge protector had and E4 error message--too many amps.

These are 15 year old electrical components--could it be the main panel breaker switches need to be replaced.

Many thanks for any help you can offer.

[twinboat]

First off, the 20 amp air conditioner breaker should have tripped, not the 50 amp main breaker.

Every item has a 15 or 20 amp breaker, even the inverter/charger ony has a 30 amp breaker.

Was any of the body damage you had fixed near any electrical wiring ?

Could have a damaged cable shorting out.

[windsorbill]

You said the main breaker tripped WITH the air conditioner breakers off, Is that correct?

If so, I'd suspect the main breaker is weak or you have a intermittent short. Twin boats already asked the question about could there be some wiring damage from what ever caused you to take RV in for body work.

[GDGorsuch]

Thank you. The first thing I suspected was a defective/weak main breaker--the RV dealer said no-cause was AC unit pulling too many amps. That cannot be my problem now as the breaker is tripping off with almost no load.

I understand what you write--the 20 amp AC breaker should trip first.

Body damage not was the cause--I was hit by a TT last Nov damaging several basement doors. With a temp fix we used the coach (not FT) since last Nov. Took months to find replacement doors and then get on the bodywork schedule.

What would make the 20 amp front AC breaker clicking noise. None of the others make a noise.

Would you replace the main breaker? All the breakers?

[twinboat]

I would disconnect shore power and shut down the inverter/charger , then remove the main and A/C breakers.

Look at the contacts for any burning or discoloring on the contacts of the bus bar and breaker contact points. Heat will cause breaker trips.

[YC1]

You probably have a load shedding EMS system and are likely hearing a load shedding relay dropping things out.

Main breaker will not/should not trip as mentioned for an AC. Those are protected downstream but that power must first pass through a relay contact.

Are you on 30 amp shoreline?

The dealer already mis-diagnosed the issue or simply missed all the symptoms.
Perhaps the dealer had a solid 50 amp supply and this is why he could not duplicate the issue. Old AC's especially if dirty can draw a bit more current.

I used to see mine drop 2-3 amps after a good cleaning. We were in very dusty conditons.

How long have you had the coach and how familiar are you with the EMS/Load shedding system?

Dropping a pair of fresh breakers in is easy and not that costly.
If you are convinced the breakers are bad then you should go ahead and open the panel up for inspection.

Use caution and your nose and eyes to inspect the area closely. There should be a circuit board along the right side that is a common failure item.

Disconnect shoreline before removing the panel for safety.

[RobRoy]

Some years back I had a similar issue, and it was driving me nut because I was guessing due to it being intermittent.

Then I got lucky and struck gold when I opened the 110vac circuit panel and opened up the panel to get inside and found those POS wire nuts they use to save money to build these coaches loose and as I checked them found one that was burnt black and the wires just barley touching….and Walla! Problem solved.

These coaches are like your house on wheels and take all the shaking, rattling, rocking and rolling for 10k thousands of miles and for years and years and take a severe beating and again many connections IMO not rated to take this kind punishment.
IMO no 110vac wiring in something that takes a beating like these coaches do should use wire nuts …what a shame.


If I did not see anything obvious, I would start by making sure every wire connection was tight from the Inverter / Transfer switch / Circuit Breaker panels / Battery boxes / all the run boxes.
It should only take a couple hours at most ......and cheap inshowunce.

IMO it should be annual or bi-annual routine maintenance depending on the usage to inspect all the 110vac related electrical fasteners accessible.


Just my $0.02 and probably worth even less

Happy Hunting.

[GDGorsuch]

Thank you for your suggestions. I’m home now so will get into it. You mentioned shutting down the inverter—is that via the breaker, turning off at the control panel or another way?

[YC1]

Please provide feedback on post 6 if you wish any follow up.

"The breaker for the front AC when turned to ON makes a clicking noise. Sometimes just for 4-5 clicks, sometimes clicking until I turn it off.""

Breakers don't click like that. You are most likely hearing load shedding relays opening and closing. Those you can hear.

I am enclined to believe you have a display panel with controls for the inverter/charger and may be telling the story.

[GDGorsuch]

Again, thx for your help. Over the weekend, at the camp site, hooked to 50 amp. Here at home, hooked to 30.

Opened the breaker panel, all appears to be clean and tight. Each breaker testing OK. I don’t know how to post photos but the clicking seems to be coming from the right and behind the circuit breaker case—NOT the front ac breaker as I thought over the weekend. Now there is clicking when I switch on the clothes washer.

The clicking is for 4-5 clicks, then stops—no load when clicking.

The RV dealer said rear ac pulling too many amp—once over the weekend I tried to start it on heat—that’s when I got an error code on my Hughes device and briefly saw 61 amps on the inside control panel. After that I could not get it to come on at all.

Today I got the rear ac to come on briefly, saw 63 on the control panel, ac shut down. So, perhaps RV dealer correct—problem in ac unit.

When the rear ac came on and shut down no breakers tripped off.

That does not explain why the main breaker tripped several times over the weekend with almost zero load. The main breaker seemed to be in tight, not dirty or charred.

All the fuses near the breaker box are ok. Although the main breaker tests OK, would you replace it? Thx again for your help.

[YC1]

You may have two problems or the same one causing the strange main breaker to trip. You might indeed have something drawing too much.

Since you are on 30 amp now and it is obvious your load-shedding relays are clicking let's try an experiment to settle things down.

Turn off your Air conditioner breakers. Both of them. Nothing else because you can cause some strange symptoms when some breakers are turned off.

The load-shedding system that the PDF shows may just be doing its job.

When on 50 amps the load shedding is disabled so is not a factor.

Since you were tripping on 50 amps it is important to chase that heavy load/short.

Turning on the generator at this time is not something I would recommend. It too bypasses the functions of the EMS board. (technically speaking)

So no generator because that may just confuse the issue.

I am standing by for your response.

Your load shedding relays should stop clickng (after a couple of minutes) when first turned on take a look at the display where your control is. There is a time delay when 30 amps is first turned on.

[YC1]

Ignore the PDF troubleshooting file attached for the moment. It starts off a bit differently but is a good reference picture and explanation as we progress.

Your RV technician could indeed been correct saying one AC is drawing too much.
Was it in the AC mode or heat strip mode?

Once you get the main breaker to stop tripping you can turn on one AC breaker and read the display. Then turn it off and turn the other AC breaker on.

Note: I do not mean for you to turn on the AC via the thermostat yet. Just checking the power feed to the AC units.

If you do not get a current draw for either you can turn just one AC' on via the thermostat and check the display. Turn it off and check the other one.

[twinboat]

You indicating 61 amp but plugged into a 30 amp supply and that's not tripping.

Somethings very odd.

[YC1]

Note, remember me saying to turn off JUST the Air conditioner breakers?

Re-reading your last post I caught something. IF your dryer breaker is off, be sure to leave it on. No reason, just policy.

I mentioned having any other breakers off can cause strange symptoms.
The dryer is one that can indeed cause "strange problems".

Turning mine off recently to repair my dryer caused weird EMS relay clickings.
There was a recent thread on this breaker and it seems the EMS looks for voltage on that Leg for some strange reason. So be sure it is on.