Microwave and converter fried at campground

[Mike_Schriber]

Just got set up at a campground in Colorado Springs and I have a big problem. Everything seemed to be working correctly electrically initially but when we came back to camp I found the front air conditioner breaker blown, the microwave off and the battery not charging. I reset the AC breaker and the unit seems fine.
I then checked the outlets for the microwave and converter (each on a separate breaker) and they had power. The converter smells fried and is not putting out any power and the microwave appears to be history.

Doing more testing, I used a circuit checker to test the other outlets. One circuit showed that the hot and ground were reversed (the laptop plugged into that circuit also stopped charging). I switched from the 50 amp plug to the 30 amp and the circuit showed good. I'm now figuring that one leg is wired wrong at the pedestal on the 50 amp outlet. However, I switched back to the 50 amp circuit to double check and now the circuit shows normal.

I'm really stumped. I know it's not anything on the motorhome side but I can't explain the shifting readings. I plan to have some words with the campground management in the morning and I'd love to have some idea what's going on with their power before I do.

Any thoughts?

Thanks!

[wnjj]

Mike Schriber wrote:
Electrician verified a loose neutral. Pedestal is fixed and I'm waiting for the campground manager to get in touch to talk about repairs.

Excellent news that you/they found it. Hopefully the repair side goes as well for you. If you can figure out all of the appliances that are on the same leg as the converter, be sure they are all ok since they all saw an overvoltage. You can probably tell by the breaker position in the panel. Every other slot is opposite leg.

[Mike_Schriber]

Electrician verified a loose neutral. Pedestal is fixed and I'm waiting for the campground manager to get in touch to talk about repairs.

[Mike_Schriber]

Just isolated the problem to the pedistal. Waiting for the campground manager to come over.

Thanks for all the assistance in figuring this out!

[pianotuna]

Before I plug in the RV I test the outlet under load with a kill-a-watt and polarity test light.

[wnjj]

Mike Schriber wrote:
Assuming that it may be my plug that's defective, if I continue to only use the 30 amp adapter that should prevent a similar overvoltage from happening again right?

If the neutral goes open or resistive again, you could have low voltage but not over voltage.

[Mike_Schriber]

Assuming that it may be my plug that's defective, if I continue to only use the 30 amp adapter that should prevent a similar overvoltage from happening again right?

[Mike_Schriber]

That makes sense. I just checked the pedestal and it seems fine. One leg has lower voltage than the other but I'm pretty sure that doesn't indicate anything in particular. I thought I got an open neutral on one leg but it went away. It could have been probe placement or a transient. I can't be sure. I really have no way to test my cord either so I'm stuck. I might experiment with some load tests using a heater and see if I get a failure again (with everything else unplugged)

Keeping the rig plugged into the 30 amp outlet via an adapter for now.

wnjj wrote:

Mike Schriber wrote:
Thanks for the feedback. I am using one of those three light testers. I keep one in the rig as a quick and convenient way to see if an outlet has power. The reversal indication was a surprise. At the time no other AC appliances were running.

I'll be checking the pedestal with my meter this morning for a more in depth assessment. I'll also look over my cord.

The AC likely pulled enough current through the compromised neutral to finish opening it up. Once open, a small draw on one leg in the RV will keep the neutral pulled to one side (showing hot-gnd reversed) even with the AC now off.

It's a bummer situation and I wish you the best.

[wnjj]

Mike Schriber wrote:
Thanks for the feedback. I am using one of those three light testers. I keep one in the rig as a quick and convenient way to see if an outlet has power. The reversal indication was a surprise. At the time no other AC appliances were running.

I'll be checking the pedestal with my meter this morning for a more in depth assessment. I'll also look over my cord.

The AC likely pulled enough current through the compromised neutral to finish opening it up. Once open, a small draw on one leg in the RV will keep the neutral pulled to one side (showing hot-gnd reversed) even with the AC now off.

It's a bummer situation and I wish you the best.

[Mike_Schriber]

Thanks for the feedback. I am using one of those three light testers. I keep one in the rig as a quick and convenient way to see if an outlet has power. The reversal indication was a surprise. At the time no other AC appliances were running.

I'll be checking the pedestal with my meter this morning for a more in depth assessment. I'll also look over my cord.

wnjj wrote:
You had an open neutral between the campground and your RV.

I assume you used one of those 3-light testers? All the lights do is show voltage between each of the 3 pairs of pins on a 120V recepatcle. They are literally 3 lights wired between the 3 combinations of 2 pins. If there's voltage between the pins, the light lights up. Yellow lights are between hot and neutral and between hot and ground and the red is between neutral and ground.

Normally in a working 120V recepatcle there is only voltage between hot and neutral and between hot and ground. Those are the 2 orange lights. What it calls hot-gnd reverse (one orange and a red light) is when there is power between ground and hot (orange) as well as between ground and neutral (red). It assumes the ground and hot have their wires swapped. With this assumption there is 1 hot and 2 "cold" pins.

The problem is with an open neutral on the 240V RV supply, the neutral will move closer (in voltage) to the hot leg with the most load. What the 3-light tester sees at a 120V recepatcle on that leg is power between hot and ground and also between neutral and ground...just like hot-gnd reversed, except now there are 2 hot and 1 "cold".

When the open neutral happened, half of your RV's 120V circuits dropped to nearly 0 (the half that showed the reverse) and the other half climbed to nearly 240V. The AC likely pulled the one leg way down, eventually tripping the breaker but not before frying the microwave and other things on the opposite leg.

The issue may be in the pedistal or it may be with your cord. Since unplugging and replugging in fixed it, it could be the plug, recepatcle, a wire behind the recepatcle or simply the connection between them. It may be tough to prove the park is as fault (if they even are).

[Mandalay_Parr]

Yes, buy the Progressive Industries 50 amp EMS.

[Bobbo]

While I have nothing I can add that will help your current situation, I want to reiterate what has been said about the PI EMS-HW50C. It would have saved all of your appliances/electronics by shutting off all power to the RV as soon as the power went bonkers. Whatever you do, make the installation of one a part of your repairs. As a matter of fact, you would not have even known you had a power problem unless you had read the PI display that told of the previous error that it encountered.

[jerseyjim]

Your situation is why I have a Progessive Industries 50AMP EMS. Any problem from the pedestal would be caught BEFORE the RV gets any power.

With me,a nearby lightening strike fried my fridge and damaged my INverter. THEN I bought the EMS. No problems since even with thunderstorms.

[wnjj]

You had an open neutral between the campground and your RV.

I assume you used one of those 3-light testers? All the lights do is show voltage between each of the 3 pairs of pins on a 120V recepatcle. They are literally 3 lights wired between the 3 combinations of 2 pins. If there's voltage between the pins, the light lights up. Yellow lights are between hot and neutral and between hot and ground and the red is between neutral and ground.

Normally in a working 120V recepatcle there is only voltage between hot and neutral and between hot and ground. Those are the 2 orange lights. What it calls hot-gnd reverse (one orange and a red light) is when there is power between ground and hot (orange) as well as between ground and neutral (red). It assumes the ground and hot have their wires swapped. With this assumption there is 1 hot and 2 "cold" pins.

The problem is with an open neutral on the 240V RV supply, the neutral will move closer (in voltage) to the hot leg with the most load. What the 3-light tester sees at a 120V recepatcle on that leg is power between hot and ground and also between neutral and ground...just like hot-gnd reversed, except now there are 2 hot and 1 "cold".

When the open neutral happened, half of your RV's 120V circuits dropped to nearly 0 (the half that showed the reverse) and the other half climbed to nearly 240V. The AC likely pulled the one leg way down, eventually tripping the breaker but not before frying the microwave and other things on the opposite leg.

The issue may be in the pedistal or it may be with your cord. Since unplugging and replugging in fixed it, it could be the plug, recepatcle, a wire behind the recepatcle or simply the connection between them. It may be tough to prove the park is as fault (if they even are).

[Mike_Schriber]

Yep. I was going to ask around tomorrow. However, I have a feeling that it's something with the pedestal. Getting a reversed hot and ground on one circuit isn't likely to be utility company related.

I'm still trying to figure out how something like that can fix itself...

[MrWizard]

might talk to other campers

IF there was power line problems, you won't be the only one

BUT it it was the utilty company, you will have to deal with your own insursance for fixing this

thats why so many people use a 'over voltage protection' and under vlotage and transient protection, in short a 'cut out device that monitors line and disconnects the RV