What could this electrical issue be?

[RMD3819]

Scenario:

Campground with brand new electrical pedestals. Plugged our 50A in. The first few days it appeared quirky. Mainly power drops then would return to normal. We have a small desk fan and you could her the spinning slow down then pick up. Did not seem to be unusually heavy loads.

Three days in we lose power. No breakers trip. Power comes back on in a few minutes. A few minutes later power loss again. We shut off the A/Cs and as much as we can but still lose power in the coach. This cycle repeats itself several more times.

The green light on the 50A cord remained on at all times.

Ranger comes out with a voltmeter which shows 120/120 all good. Explains that they cannot mess with this as it is under warranty and will need to call the contractor. Offers to move us to a different site. Due to logistics we say we'll try the 30A and see what happens.

Plug the 30A dog bone in and everything works great. We drop down to one A/C. We go to unplug and the dog bone is burnt. See pic.

I'm thinking the EMS system shut things down since the green power on light was always illuminated on the power cord.

I'm thinking about getting this monitor to help in the future: http://www.trci.net/media/174710/403...505-00127a.pdf

Ideas?

[ej1144]

The only cause for the burn is usually to much amperage draw. Sounds like the voltage is unstable. Lower voltage creates high amperage.

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[bruceisla]

There is another possibility .... the dogbone is junk. Get one of these:

https://www.amazon.com/Progressive-I.../dp/B002UC4T08

Another possibility is loose contacts in the pedestal outlet. Also, make sure the adapter is supported ... don't let the adapter and cable hang without support ... 30 amp plugs spread the contacts in the outlet.

[vsheetz]

New CG pedistals? Even more suspect that they don't have things sorted out.

[charliej]

Sounds like EMS is shutting down do to low voltage. Does your EMS show error codes?

[hivoltage98]

There's a very good possibility that someone forgot to tighten the main lugs on the pedestal or at the breaker panel. Bad connections= heat and arcing

[rvadventure]

Originally Posted by ej1144

The only cause for the burn is usually to much amperage draw. Sounds like the voltage is unstable. Lower voltage creates high amperage.

Sent from my LG-H910 using iRV2 - RV Forum mobile app

I agree with this, do you have a voltage meter you can see in the coach? I'm surprised at how many parks the voltage drops well below 110 volts. You can buy a plug in meter at CW. That shows you the voltage. When I run my generator it stays around 117 to 120 volts, I was in a campground last week that dropped down to 106 volts. Regards

[nehog]

Originally Posted by ej1144

The only cause for the burn is usually to much amperage draw. Sounds like the voltage is unstable. Lower voltage creates high amperage.

I'm going to disagree to an extent. Even 'normal' or design amperage can cause this if the receptacle pin tension is weak (resulting in a higher resistance connection), or if the pins are damaged (again resulting in a higher resistance connection). As the OP says this was a 'new' installation (under warranty...) I'd suspect someone may have used low grade connectors.

One should always check the connector when plugged in from time to time. You should not feel any warmth at all. If you do, power off, disconnect and figure out what the problem is.

[Soppy]

That monitor will help. You will be able to see the voltage and current at an instant. As for your burnt dogbone , that's just from a bad connection and drawing a lot of amperage. It's possible the pedestal receptacle is at fault. Sounds like there are a lot more problems in that pedestal.

[Gary RVRoamer]

The burned 30A plug indicates an overload, but you need to be aware that the 30A rating is for peak load only. The sustained load (30 minutes or more) rating is 80% of that or 24A. Thus a 50A coach plugged to a 30A outlet has an excellent chance of drawing near 30A for long periods with the a/c running plus other loads. Bottom line is that the burned 30A plug is probably NOT significant re the fluctuating power.

As for the fan speed, it does indeed suggest that the 120v power (voltage) is varying. Assuming of course it is a 120v fan. If it is 12v fan, then the pedestal voltage is not directly involved.

The 30A EMS would shed a load if 30A is exceeded on a 30A shore connection, but would not cause a voltage variation. Its zero volts or full volts on each circuit that it controls.