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nanseecat

GFI Outlets/Battery Charging/Inverter-charger

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All of the GFI receptacles in our Coachman Mirada class A motorhome have no juice.

The standard receptacles work fine.

We are hooked up to 50 amp power.

Anyone have any insight into how we can repair this?

Thanks!

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nanseecat,

Welcome to the FMCA forums.

Find your 120vac circuit breaker box. It will look very similar to one in a house. Look for one or more circuit breaker handles that is in the center position. This will indicate an open breaker due to previous overload on that circuit. Also you should have a circuit breaker that feeds your inverter. It needs to be in the on position also.

If you don't see any centered handles, then turn all the breakers off, then back on. One of them will feed one or more of the ground fault receptacles (GFR). You should only have two or three GFR's in the coach. But the number is not important right now.

Another possibility: Many coaches have some GFR's not fed by the inverter, and some GFR's that are fed from the inverter. In our coach we have that situation. With that in mind, check to see if your inverter is turned on. If your inverter output feeds the GFR's directly and it is powered down, the you will have no power at the GFR outlets.

Also some coaches will have a secondary circuit breaker panel that is fed from the output of the inverter. If you have one of those, check that all the breakers are on. Exercise them off to on as described above.

Let us know if this helps.

Chuck

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Thanks for the info Chuck.

Something keeps blowing the circuit...every time we reset, it trips again.

We haven't been able to narrow down what is causing it.

In the meantime, we are making do with extension cords.

I appreciate the welcome!

Nancy

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Nancy posted:

"Something keeps blowing the circuit...every time we reset, it trips again." What does the circuit breaker that keeps tripping (blowing) list on the breaker's handle? It will be molded into the plastic as 15, 20, or 30.

If the circuit breaker rating is 15 or 20 (amps) that would indicate to me that something is plugged into that circuit and is shorted to ground OR you have a miswired or defective GFR in the coach. I have seen both situations.

Before doing anything else, unplug everything on every outlet in the coach. Don't forget outlets for washer/dryer, in storage area, engine area, and exterior. Does the breaker continue to trip when switched on? If so you have a short in the wiring or a receptacle/fixture and will need professional help to find it. Do you have a wiring diagram for the coach?

If the circuit breaker rating is 30 that means it is feeding your inverter and the wiring to the inverter or the inverter itself has a short to ground.

You didn't say is this a new (to you) coach or have you had it for some time. If the latter I presume the circuit worked OK previously. Which is it?

Please let us know what you find.

Chuck

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Nancy,

Let's clarify what is blowing/tripping.

Is it the breaker in the 120 VAC breaker box? And flipping the breaker off and back on momentarily resets it?

Is it the GFI itself, so pushing the "reset" button on the GFI momentarily resets it?

In either case, start troubleshooting by unplugging everything plugged into the circuit that is blowing. This may include things like the 120 VAC plug for the refrigerator (accessible through the outside refrigerator access panel). You may also have items in the basement plugged in.

If that doesn't trip the breaker or GFI, start plugging things back in one at a time until you find the offender.

Another question-- has it rained lately or have you washed the coach. Many coaches have outside 120 VAC outlets that when wet can trip the circuit.

Brett

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Thanks for all the replies!

It's the GFI itself that keeps popping. We've eliminated everything inside the coach so it's got to be something either on the outside or somewhere internally in the wiring. We're thinking right now that it's probably something that needs service.

Again...thanks for the responses!

Nancy

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Nancy,

Any outside outlets? Particularly if the get wet, that is an easy "suspect". With shore power off, pull the outlet out and verify that no water is inside. Same for refrigerator outlet, since water can blow into the back of the refrigerator area.

Brett

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Guest BillAdams

What a timely topic. We left our coach in service while we went on vacation for them to check an issue with our air suspension system. Nothing got done but when we returned we could see the coach had been driven but nothing done. We arrived home after 10 days and found that one leg had 150+V power (as high as the meter reads) and the other leg was very low. We found the plug that connects to the coach was only half way inserted. We powered off, got the plugged fully inserted and powered back up. Both legs now showed proper power. The microwave is dead but everything else appears fine except for the GFI circuits. This is a 1988 coach and there are no GFCI plugs but rather 4 GFI circuit breakers in the 120V breaker box. Not every circuit works on the inverter but most do. If I am plugged into shore power or running the genset the 4 GFI breakers trip. If I am on the inverter they do not trip but they these are the circuits that are not powered by the inverter. I have checked the cord, I have tried different shore power plugs. The power appears to be fine at the transfer switch and I have yet to open the boxes after the transfer switch but that's the next step. I wish I knew more about what could cause this kind of an issue but with no GFI plugs it could be any connection anywhere that is causing a ground fault somewhere.

I know that this is not a good idea, but is there some way to by-pass the GFI breaker to at least see if the circuit is functional?

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Bill,

You said that your plug was not fully connected, but was almost OK when reconnected. You also mentioned your coach was a 1988. If you can, check out your shore power plug. Sometimes the connections can get some corroded on them. Just a thought.

Good luck.

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Guest BillAdams

It's a brand new shore power cord so I know that's not the issue. Whatever happened, happened while the coach end of the plug was not fully pushed into the socket causing a bad connection there.

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Sorry Bill, I wasn't talking about your power cord, I was referring to the receptacle(you plug your power cord into) on your coach. After some time the connections corode and even loosen a bit. Just a thought.

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Guest Wayne77590

Wow! So many possibilities. Bill, all I can say is start trouble shooting with a meeter from the source.

Typically the circuits are in series with each other so if there is a problem on one receptacle the entire line for that series will shut down. As indicated in a previous post, the GFCI Plug breakers can and do go bad. They also "wear out" if they are tripped over and over again. So it is probably best to just go to a hardware store and buy replacements and get it over with. They cost more than a $1.95.10. Just remember that if you do replace them they do not conform to ac lines where you can change he polarity (switch wires) without "to much cause and effect." GFCI outlets are clearly marked on the back with the word "Load, or Hot, or Line" that is the point where the hot wire goes into. The hot wire, if wired correctly by the electrician, is the "Black" wire, with white being the neutral. Ground is usually the bare copper wire.

However, GFCI is different: "A GFCI monitors the amount of current flowing from hot to neutral. If there is any imbalance, it trips the circuit. It is able to sense a mismatch as small as 4 or 5 milliamps, and it can react as quickly as one-thirtieth of a second." (How Things Work)

So any mismatch of electricity anywhere on the GFCI circuit can trip the breaker. It is necessary to isolate that problem, which is what you are trying to do here, and I would attempt it so: Turn off the breakers, remove the all the outlets in that series and disconnect the wires. Now start at the source, connect one outlet at a time starting with the GFCI, turn on breaker and test the outlet. Continue on to see if there is any anomaly that will trip the GFCI. It's a days project to test them all. PLEASE turn off the main breaker anytime you are connecting of disconnecting electrical circuits.

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Guest Wayne77590

"A GFCI monitors the amount of current flowing from hot to neutral. If there is any imbalance, it trips the circuit. It is able to sense a mismatch as small as 4 or 5 milliamps, and it can react as quickly as one-thirtieth of a second." (From How It Works}

Any minute imbalance in the circuit will cause the GFCI to trip. Most likely the same applies to the GFI Breaker.

A question I would first ask anyone is if they have changed out the GFCI outlet. If the answer is yes I would then ask if they noticed on the back of the outlet a point connection that was labeled "load, hot, or line." That is where the hot, black is hot in ac circuits if the electrician wired it properly, is hooked into the GFCI. White neutral, bare copper is ground. If nothing has been changed and everything was working properly, when was the last time? What did any technician disconnect and reconnect that may have an imbalance? It is not a short process to trouble shoot an electrical problem in a motorhome.

Everything needs to be disconnected from the GFCI Outlet series being worked on. That includes taking the outside vent off the refrigerator and checking to see if there is an AC plug back there and unplug it. If everything is unplugged (everything) and it still trips it could be the GFCI outlet is bad. They are known to go bad. I would not hesitate to replace it with a new one just for good measure. As GFCI's trip over and over they become weak and less imbalance is needed to trip them and eventually they just stay tripped.

If replacing the GFCI does not do it, then it is most likely something that was overlooked in unplugging everything so check again. If everything is unplugged, it is tedious but, remove every receptacle in the series for that one GFCI outlet. Make sure you turn off the main breaker or unplug from the pedestal before you start connecting or disconnecting electrical wires. Find the first point off of the main breaker that has wires (may be the GFCI) and turn the power on and check the wires. If it is coming from the main source it should read 120v. Move to other outlets and find the initial source of the power. Once found, hook it to the receptacle and remember to turn the main off first. Turn on, and you should still have power at that source. Continue to each point and repeat the process. You should find the problem. Do remember that you may have some hidden AC plugs, like microwave clock, ice maker, refrigerator, etc..

Gotta go - good luck.

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Guest BillAdams

As I mentioned, I have no GFCI outlets. The GFCI function is handled by the brand new GFCI breakers I installed 3-4 months ago. The breaker box has about 8 breakers in the left column and 4 breakers in the right followed by 4 GFCI breakers. Not all of the plugs in the coach are powered by the inverter so when I cut off all power and turn on the inverter the GFCI breakers will reset (as they are not powered) but as soon as I fire up the genset or plug into power all 4 breakers trip immediately. I like the idea of disconnecting all of the plugs that are not getting power and working backward from there but since I am assuming that this leg got hit with the 208/240V I think there is a possibility that somewhere past the transfer switch I will find a melted wire.

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Bill,

Per your first post, you can simply replace each Ground Fault Circuit Breaker (GFCB) with a standard circuit breaker. All the outlets downstream of that breaker will probably function OK, but it is a good idea to check all four circuits.

Whether one talks about a Ground Fault Receptacle (GFR) or a GFCB, both are "ground fault interrupters", and both sense an imbalance in transverse current between hot and neutral lines. They do not sense current from the hot line to ground line as many people erroneously think. That is why you won't find any green or bare ground wires on a GFCB. And they both have active electronic circuitry inside them that measure the imbalance current and trip open the embedded contactor.

As you mentioned, if the coach somehow got 240vac across the GFCB's they may be fried. Again easy to check with a breaker if you have a spare, or purchase another CFCB and replace one of the defective ones as a test.

But before all that, take a voltmeter and make sure your main panelboard and all sub-panels have 120vac to neutral and ground from each hot leg. And 240vac across the hot legs. This will only take a few minutes and will provide a firm benchmark for further testing.

I thought you had a HW-50C of something similar to prevent this sort of thing. Or did you, and still suffered an anomaly? Let us know what you find.

Chuck

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Guest BillAdams

I do not have any kind of energy system. Almost bought one at the Madison and/or Escapees rally and put it off. That was an expensive decision.

The GFCI breakers have one wire going to the ground bar and then a black wire and a white wire that go to 2 separate terminals on the one breaker. I have not been able to get a new non-GFI breaker to work in replacement of the existing breaker no matter what combination of wires I use. I tried just moving the black wire from the GFI breaker to a function standard breaker. This worked for a few seconds and then things started buzzing like crazy and I had to shut it down and return things to their previous configuration.

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Bill,

I am concerned that you may have a safety problem on your hands. You indicate ALL your GFIC breakers pop as soon as you connect power from either a shore cord or your genset. Also, this problem surfaced after you left the coach for repairs to the air system.

Let's remember that coach wiring is different from house wiring. One cause of ALL the GFI breakers triggering is a shorted or crossed neutral/groung wire as might have happened if the mechanics inadvertently put a screw or drill bit through a wire while repairing the air system. This exactly the danger discussed in the excellent May-July articles "Wired for Safety" in the FMCA magazine.

So, with great respect to some of the other contributors, let me recommend against replacing GFI breakers with non-GFI breakers. I would also query the technicians who worked on the air system and learn EXACTLY what the did and where they did it. Those GFI breakers were installed for your safety and whatever is triggering them needs to be identified in a careful manner.

Good luck. Please let us know what you find.

Tim

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Guest BillAdams

I am guessing the that 240V that was left surging through the coach for at least the entire weekend has melted or shorted something critical and will be delving into that side of the diagnostics today. The company did no work on the coach other than a test drive and then plugged it back in. It might have had the 240V power on one leg for a week or more.

I have 4 lines coming into the breaker box. The red and black hot, bare ground and white neutral (I assume). There is continuity between the ground and neutral wires according to my meter but it makes a strange buzzing noise on the meter instead of the clean high pitch tone that's normal.

The red and black read 240 and I can go red to ground or neutral and read 120 and I can go from black to ground or neutral and read 120. Is that right or should it only read 120 with one of those 2 combinations?

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Bill was your coach plugged into 50 or 30 amp at the service shop? My reason for asking is that 240V has two 110V and a neutral. 30 amp 110V has one 110V a neutral and a ground. Where a 50 amp 110V does have two 110V wires one Neurtal and a ground. I know you know this but what I am trying to get at how could 240V get through to your system? Now trying to be a smart postieria, just wondering. Did the service shop use some kind of adapter?

Hope your problem turns out to be minor and would like to hear what is found.

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Guest Wayne77590

Bill,

Your metering is correct with red and black being 240 across, and then each of those to neutral or ground is 120v. If you have not changed anything, and all the technicians did was plug it into the same type of configuration, I'm wondering where you got 240v plugged in. You stated that there was 150v on one leg, and lower voltage on the other. The Progressive Industries 50 amp surge (etc.) will kick off at 134v and 104v (both of those numbers are outside the 10% range, but they seem to work) At 150v I'm wondering if there is anything in the "line" that could have had an electrical failure and shorted out. Bill, you are more than intelligent when it comes to circuitry so you know that if a transistor, resistor, capacitor, etc., in any electronics circuit shorts out it affects everything on the line. Most cases the electronics fuse blows, but in the case of GFI's it is a very small imbalance that will cause the trip. What I'm surprised with is the statement that all of the GRI's trip when gen or shore power is hooked up. I guess my question would be, what in the circuitry of the transfer switch, inverter, our auto switch could cause an imbalance to all four GFC's.

Trust me, I do not envy you troubleshooting this one. I wish I were there. I could sit back with a cold one and watch.

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