Odd electrical issue

**Iwritecode** · 05-20-2019, 08:52 AM

So I had a situation over the weekend that still has me completely baffled. Get ready for a bit of a lengthy post...

My wife and I are on a seasonal site. Got to our trailer Friday afternoon and I was about to put some food in the fridge when I noticed that it was way too warm. The light was on inside the fridge. The lights above the fridge indicated no problems (check light was not on). It is a 3-way fridge so it should've kicked over to gas or battery if it had a problem. I know I didn't lose power because the clock on the microwave was still set.

Now here's where it gets weird. The last time this happened, it was discovered that we lost power on one leg of our shore power. We had to have the CG come and change the breaker on the pedestal.

The difference in that situation was that half the stuff in our trailer didn't work. So I started going around checking everything thinking I might have the same problem here. Every single light and outlet in the trailer was working fine. Well, except for the one our TV was plugged in to. The outlet had power, but the TV wouldn't turn on. Also the lights on our ceiling fan were very dim. The fridge in our outdoor kitchen was also not running.

So we started flipping switches and tried turning on our WH. We have switches for both gas and electric. The second I flipped the switch for the electric WH, the lights in the ceiling fan got brighter, the TV turned on and the fridge in the outdoor kitchen started running.

I've had odd things happen when the electric element in the WH goes bad so my initial thought was that maybe that was the culprit. I did make the mistake of trying to run the furnace before we left to get a new element. It kicked on with no problems but the lights went dim and the TV shut off while it was running.

So I went out, got a new element and replaced it. Same situation. Everything worked as long as the switch was turned on.

So I just ended up going to bed and figured I'd look at it in the morning.

The next morning we get up and for the hell of it, my wife flips the switch to OFF. Everything works fine.

I monitored everything throughout the day periodically checking the TV and both fridges. By Sunday morning, both fridges were nice and cold again and everything was working as it should.

My question is, what in the world happened? I have a theory that we may have been getting low voltage from the CG pedestal. That would explain why the TV outlet was getting power, just not enough to turn it on. The fridge was getting enough power to run the lights, but not enough to kick on the condenser.

What I don't understand is why did flipping the switch for the WH make everything work?

Thoughts?

Gumpster808 · 05-20-2019, 08:59 AM

Sounds like there was an issue and the common being connected thru that breaker caused things to fire up properly.

They can act strange sometimes. Had a loose ground in an old house once and ended up with 220 on a 110 outlet.

You have an ems that had any codes etc?

SlowrideHD · 05-20-2019, 09:05 AM

Sounds as if you have a grounding problem. You might want to drive in a grounding rod since it is a seasonal site and make sure all your 120v is properly going to ground. Sometimes those wiring circuits to pedestals are pretty sketchy.

llr · 05-20-2019, 09:32 AM

It is not a ground issue but sounds like a loose common connection, that can supply near 240V across some items depending on what is turned on on each side of the line.

I would remove power and check all the commons you can, if no issue found then have the park check their panels.

Do you have an EMS? If so it should have tripped if the common issues was before it so the issue would be after it.

FYI, most if not all lights would be 12V so not directly connected to the issue but the converter was probable not getting full power. Also you would not notice changes turning the WH on and off unless it needs to heat the water at that time.

Edit: the lose common is from the input to the panel back to the sites panel. Not on the individual circuits as that would only impact one circuit and other circuits would not effect it.

kenandterry · 05-20-2019, 09:32 AM

That’s great detail into your story, and I agree things are strange.

Not sure I can offer any solutions yet, however...

Even though you’re a seasonal, do you have any power surge protection equipment? I use Progressive Industries, and their better units have display codes to assist with troubleshooting. Also, you mention having power on some of your outlets. Do you have a digital meter? It’s one thing to have “power” but how much?

**Iwritecode** · 05-20-2019, 09:49 AM

Quote:

Originally Posted by kenandterry

That’s great detail into your story, and I agree things are strange.

Not sure I can offer any solutions yet, however...

Even though you’re a seasonal, do you have any power surge protection equipment? I use Progressive Industries, and their better units have display codes to assist with troubleshooting. Also, you mention having power on some of your outlets. Do you have a digital meter? It’s one thing to have “power” but how much?

I don't have an EMS. It's been on my list for a little while now but I've just never gotten around to it.

I have a meter but it's a cheap one. I really need to get a better one. I actually didn't think about testing the outlets. I was just using a little night light and plugging it into each outlet.

It's just weird that flipping that one switch for the water heater would cause everything to go from "low power" to "full power".

CedarCreekWoody · 05-20-2019, 10:09 AM

Check your voltages while under load. The water heater is high amperage. When turned on it can reduce the voltage on that line. If voltage drops under load check for loose or corroded connections, particularly on incoming lines. It sounds you are 50 amp so check both incoming 120 volt feeds.

myredracer · 05-20-2019, 10:18 AM

Sounds like a loose or corroded connection(s) somewhere. Hard to say where to start but I would at least look at the ground from the panel/converter to the frame.

This is what the bare (DC) and green (AC) ground wires looked like at the connection to our frame after about 3 years. Note also the tire was wearing through the green wire. The lugs the various factories use aren't really UL listed for wet locations and can/will corrode. I replaced ours with a split brass stud intended for wet locations.

Intermittent connections be a PITA to track down.

Jayhawker · 05-20-2019, 10:27 AM

I would start by checking all of your neutral (white wires) at the panel. Turn off you source power, then tug on the wires where they are connected to the neutral buss. Then check to make sure all the screws are tight.

**Flybob** · 05-20-2019, 10:37 AM

In addition to the common connections, pull the plug from the pedestal and feel and look at the prongs on the male side. A poor or dirty connection will cause the prong to heat up. If you power cord disconnects from the RV do the same on the RV end. Look at the prongs on the male end.

kenandterry · 05-20-2019, 11:01 AM

Quote:

Originally Posted by Iwritecode

I don't have an EMS. It's been on my list for a little while now but I've just never gotten around to it.

I have a meter but it's a cheap one. I really need to get a better one. I actually didn't think about testing the outlets. I was just using a little night light and plugging it into each outlet.

It's just weird that flipping that one switch for the water heater would cause everything to go from "low power" to "full power".

Home Depot has the 3 pack. All you’ll need.

TitanMike · 05-20-2019, 11:20 AM

When diagnosing electrical issues it's always best to start at the source and work downstream. If the source is faulty, and RV parks are notorious for having lousy connections at the post, that cuts a lot of work out of your search for the problem.

Whenever I hook up in an RV park, even at my own backyard pad, I insert and remove the plug several times before flipping on the breaker. This has the effect of wiping contamination and corrosion of the contacts as much as possible. Even if it doesn't fix the problem it lets you know where it is.

**Bama Rambler** · 05-21-2019, 12:47 PM

It has been said above, but that's a classic loose neutral issue. The reason turning on the water heater element remedied the problem is that it's a pretty low resistance device so it created kind of an artificial neutral (actually a potential difference).

While you're checking your equipment, I'd have the campground owners have the pedestal wiring checked.

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