HELP AC Outlets blowing devices!

[SDrummer]

Hello all,

I am currently living in a River Canyon 34RLQS0 5th Wheel that is hooked up to electrical power. I am having a odd issue with the electrical in the trailer. Some of the GFI outlets are blowing electrical devices when they are plugged in. Yesterday we plugged a toaster into the kitchen and it started smoking without even turning the device on. I also plugged my laptop AC adapter into the GFI outlet in the bedroom and it worked for about 2 minutes before blowing. The AC adapter does not give out any voltage and I verified this at my work.

The trailer has has issues in the past as it has blown the bedroom TV and kitchen Microwave as well.

I have measured the voltage on the plugs and they range from 110v-117v.

Today I tested all of the outlets with a GFI tester and they all read good indicating there are no line, neutral, or ground wires crossed.

The bizzare thing is that the plugs seem like they decide which devices they want to fry. I am currently running my heater and charging my phone on the same plug that blew my laptop AC adapter yesterday.

Any help is appreciated as I worried about plugging anything into the walls fearing it will blow the device.

Thanks

[SaltiDawg]

MEXICOWANDERER wrote:
Troubleshoot. Don't guess.

Buy a 50-amp to 30-amp ADAPTER. Plug the ADAPTED shore power cord into the service.

OK?

Now go inside and load the hell out of the 30-amp 120 volt service.
...

No disrespect. Additionally, I will admit to having zero RV experience.

A fundamental rule in electrical circuit testing is NEVER rely on protective devices to function for equipment or personnel safety when testing.

If I understand the suggestion, this is absolutely terrible advice!!!!!!!

[enblethen]

OP:
I would suggest you start looking for the problem before the rig burns to the ground.
I would suggest that you start at the electrical panel in the rig. Turn off shore power, inverter if equipped,. Remove cover from the AC circuit breaker panel, Look closely at all the connections. You are looking for melted insualtion on the conductors. Pay special attention to the white wires in the back of the box. I would suggest getting some electrical grease before you start. Disconnect each of the neutrals, white wires, clean them good so they show good copper coloer. You may need to trim them back alittle to get some. Apply a liberal amount of electrical grease and reconnect. Do each one, one at a time. Check the wires terminating on the circuit breakers and do the same. The electrical grease is not as important on the breaker terminations as compared to the neutral buss which is commonly aluminum or a tinned material.
Is your electrical cord removable? If it is, you need to remove the portion on the rig and check the connections there. Do it in the same manner.
If you have a fixed cord, locate the junction box where the shore power cord changes wiring method. Inspect the splices there.
If you are uncomfortable with doing this, I would suggest getting professional electrical help!

[CA_Traveler]

SDrummer wrote:
So I went ahead and unplugged everything from the outlets and turned off all the lights. I measured the voltage with nothing on and it was 117V.

I then turned on the AC and measured the voltage again at the same outlet and it increased to 118.5V.

I checked all the outlets and on the ones I could get a reading it was the same around 118.5V.

However on two of the GFI plugs, the one in the bedroom and kitchen, The voltage readings kept fluctuating between 0V & 5V. I then turned off the AC and measured the voltage however the voltage did not change and was still fluctuating between 0 & 5V.

My girlfriend had been using the plug in the bedroom for her curling iron just fine thirty minutes prior to me checking the voltage.

Almost sounds like the voltmeter was on the wrong setting as in wrong voltage scale or DC or ... Plug in a light and if OK then you have a cockpit problem measuring the voltage.

You've burned up equipment and yet you continue to turn on high priced appliances like the AC? Hummm...

Good input from Jeff above.

[SCVJeff]

You need to be looking at these outlets with a REAL load on them. If I were you and I had wiped out that much equipment, I would go to Home Depot and buy a 200-300w bulb and ceramic base, or better, a 500w construction service light. If you I kill it, who cares...

Anyway, if you have a loose neutral that opens under load, this is the only way you can see it... Loaded.

Personally I would start at the shore plug (that itself could be the problem) and check every single wire nut and push-in, or screw terminal of every plug in the RV. I have seen this before in a residential situation and it turned out to be a loose wire nut in a switch box tying a bunch of neutrals together, and it doesn't manifest itself until it's loaded up.

Or call an electrician, which BTW I disagree with the above poster on having only an RV tech look at it. There are wire monkeys and real electricians, that for this job are far more qualified and knowledgable about this kind of thing. These problems pop up in residential and commercial structures all the time, and the results are the same.

[SDrummer]

So I went ahead and unplugged everything from the outlets and turned off all the lights. I measured the voltage with nothing on and it was 117V.

I then turned on the AC and measured the voltage again at the same outlet and it increased to 118.5V.

I checked all the outlets and on the ones I could get a reading it was the same around 118.5V.

However on two of the GFI plugs, the one in the bedroom and kitchen, The voltage readings kept fluctuating between 0V & 5V. I then turned off the AC and measured the voltage however the voltage did not change and was still fluctuating between 0 & 5V.

My girlfriend had been using the plug in the bedroom for her curling iron just fine thirty minutes prior to me checking the voltage.

[wa8yxm]

SDrummer wrote:
If there was an open neutral wouldn't that show up on the GFI tester?

Likely no it would not,, Wiring is not nearly as simple as that tester. IF the open neutral was on the branch that feeds the outlet you plug the tester into THEN it will show it.. But if it is say a burned neutral in the feeder line to the park outlet.. Very very doubtful the tester can find it.

This is why I had to use dual voltmeters to find the bad neutral in my house.. What's worse.. It need not be OPEN (Mine was not) IT just needs to be poor quality.. (high resistance)

[Harvard]

One Voltmeter will do, if the voltage is HIGH (appox > 134VAC) or the voltage is LOW (appox < 105 VAC) either reading will indicate a neutral problem.

[SDrummer]

wa8yxm wrote:
I too agree it sounds like an open neutral.. As for the single 50 amp breaker...

They make a breaker that has a single lever, but is in fact a double breaker,, I know I had the 150 amp version of it in my house. Like all breakers it comes in assorted sizes (Ever see an 800 amp breaker,,, I have.. It too was a single lever 240 volt dual breaker).

To diagnose .. One assumes you have two AC/s.. TURN OFF everythign, in fact turn off the circuit breakers that feed televisions and other electronic devices including your converter.

Leave on only the following

General outlets with nothing plugged into them (NOTE there is another way to do this) you need two such circuits, one on each side of the neutral. and at least ONE of the two air conditioners.

now plug volt meters into both outlets, ANALOG meters work best for this.

Turn on the AC and watch the meters

One drops a volt or 3, other either goes with it or stays static, GOOD

One goes down other goes UP seriously (like more than 10 volts) open neutral.

How do I know this: Happened on the sticks and bricks and that is EXACTLY how I diagnosed it.

I only have one Multimeter, do i need to purchase a second or can I check the voltage on one plug, unplug the leads of the multimeter and check the voltage on the next? Or do i need two multimeters plugged in at the second time because the voltage differences happen very fast?

Also am i checking voltages on the two outlets on the same GFI plug or on different GFI plugs on different sides of the trailer?

Thanks for all the help

[Old-Biscuit]

LScamper wrote:
MEXICOWANDERER has the best 100% sure way to find an open or high resistance nuetral.

Do not plug in anything to the 50A plug until the problem is found. You will just destroy more equipment.

OPs problem is he is plugged into power at home.....not CG where 30A is available on pedestal.

[CA_Traveler]

LScamper wrote:
MEXICOWANDERER has the best 100% sure way to find an open or high resistance nuetral.

Do not plug in anything to the 50A plug until the problem is found. You will just destroy more equipment.

Yes a good test but it puts expensive equipment at risk.

If the 50A neutral problem is before the adapter then you could easily get very high voltage in the rig. ie It certainly could be the wiring on the 50A pedestal plug or the plug itself or even upstream from the pedestal.

If you take my suggestion to disconnect or remove all equipment and then only use lower cost loads then this is a good approach.

[LScamper]

MEXICOWANDERER has the best 100% sure way to find an open or high resistance nuetral.

Do not plug in anything to the 50A plug until the problem is found. You will just destroy more equipment.

[CA_Traveler]

2 more points:

1. Although rare you can have high/low voltage due to an open neutral on 20A or 30A pedestal plugs. It happened to me and of course the problem was in the CG 240V distribution system.

2. IMHO Every 50A rig should install a hard wired 50A full power protector. I much prefer the PI unit but others like the SG unit. If you are really very very diligent about installing the portable unit each and every time then go for that unit.

[CA_Traveler]

SDrummer wrote:
I just tried plugging my microwave into the kitchen GFI outlet, and now the GFI outlet is tripping as soon as its plugged in.

STOP!!! Don't plug in good equipment with a suspected high voltage situation - you've already blown several pieces of equipment! STOP!!! Unplug or disconnect EVERYTHING like MW, HW, refer, charger, TVs, DVD players etc. DO THIS FIRST

Put a AC voltmeter on each leg and cheap loads like a light or maybe a ceramic heater(not real cheap but it can draw 10 amps).

You may/may not then observe the problem. If in fact it's a completely open neutral then it will be apparent. But an open neutral can be partially open or intermittent.

Your posts suggest you need to hire some help.

This is exactly one reason why I have a full power protector installed in my rig. If I encountered a pedestal or plug problem I'm protected. I have the PI HW 50C. Another big advantage is that it displays voltage and amps on the display inside the rig. Amps are very useful when on 20A or 30A pedestals.

[Bobbo]

The question:

SDrummer wrote:
A few of you recommended a few tests to do to see if it is actually an open neutral. Now that you guys know this is a 4 prong connection, what is the best test to do to test for an open neutral?

The best answer:

wa8yxm wrote:
To diagnose .. One assumes you have two AC/s.. TURN OFF everythign, in fact turn off the circuit breakers that feed televisions and other electronic devices including your converter.

Leave on only the following

General outlets with nothing plugged into them (NOTE there is another way to do this) you need two such circuits, one on each side of the neutral. and at least ONE of the two air conditioners.

now plug volt meters into both outlets, ANALOG meters work best for this.

Turn on the AC and watch the meters

One drops a volt or 3, other either goes with it or stays static, GOOD

One goes down other goes UP seriously (like more than 10 volts) open neutral.

Second best suggestion:

MEXICOWANDERER wrote:
Buy a 50-amp to 30-amp ADAPTER. Plug the ADAPTED shore power cord into the service.

OK?

Now go inside and load the hell out of the 30-amp 120 volt service.

If there is a flaky neutral involved this LOAD TEST will force it to show up RIGHT NOW. The other 120vac leg will not be connected so there cannot be any danger of a bad neutral causing anything more severe than the power shutting down. I assume of course that the OP's 120vac testing really revealed 120 volts and not an error within the metering device.

BUT BUT BUT BUT BUT

Have someone STAND BY the outside electrical service as you are inside the rig loading down the adapted circuit. A bad neutral can easily flame, and must be opened immediately to prevent a fire.

Although turning off the MAIN BREAKER in the RV is almost as good as having a cohort unplug the RV in case you do find a bad NEUTRAL.

[RV_Tech_101]

Your best suggestion is get a hold of a qualified RV tech. Not an electrician. Most electricians are clueless beyond wireing a light switch and can cause more damage than you already have. I agree it sounds like a 50 amp coach with an open nuetral. Real simple fix. Check all wire connections in the distribution panel and transfer switch (if applicable). Next check power source. If you know nothing if 50 amp or 30 amp plugs then this is where you need the tech. If it is an open nuetral be prepared to replace your converter and maybe some other more expensive items because your coach just got hit with 220.... oops!
Hope this helps
David
Harrison RV