50 amp service not working but 30 amp does

[chiefd]

OK.

Been struggling with this. This is our maiden voyage in a class A. We plugged in to 50 amp service and the main ac and receptacles did not work. We had no power for microwave, fridge etc. TV worked but no DVD. Back AC unit did work

Plug in 30 amp now ac works some outlets, fridge,microwave obviously can only run one ac so what’s up. Any thoughts? I have checked breakers, fuses etc. if I run the generator all things work.

[cavie]

You need a volt meter. You need to measure the ped voltage every time before you plug in. You need to know weather both line legs 1 and 2 have voltage. I suggest you purchase an EMS from progressive industries or Surge Guard.

Check all your 120 breakers. Turn the off then on. I assume you are using a 30/50 dogbone if you plugged into 30 amps. All circuits should be working if this is correct. You just won't be able to run both A/C at the same time.

If your not getting full power then something is wrong with your dog bone. here come the volt meter again.

[chiefd]

Yes I’m using a 30 amp dog bone and all is working. I’m not much of an electrician how would I check the pole for 50 amps. Do I Chavez one n ground and check each leg? What should it read?

[gmc]

Originally Posted by chiefd

Yes I’m using a 30 amp dog bone and all is working. I’m not much of an electrician how would I check the pole for 50 amps. Do I Chavez one n ground and check each leg? What should it read?

A 50A RV outlet should read 110v from EACH hot lead to neutral... and 220v between the hot leads.
When using the dog one adapter, the output of the adapter will read 110v from each hot lead to ground, and 0v between the hot leads (as the same hot lead is split between the two legs in the adapter.. This works because (most of) our rigs don’t truly use 220v - just lots of 110v.

[Bob Denman]

I would just be guessing... but I'd almost think that this problem will trace back to the condition of the pedestal.

Good luck!

[Lt Keefer]

Ask the campground manager to move you to another site. Sounds like one leg of the 50A service is out at the pole. If you had a EMS that would have told you the story prior to hooking up the coach. I wouldn't mess with someone else's facilities since you are not a qualified electrician.

[TurnerFam]

you've simply lost one LEG of your 50amp double-pole service....easy, happens all the time for some....so

check the campground's power pedestal outlet, and breaker set... as probably a loose wire is apparent in one or the other...

if not, then your own shore cord could have a loose connection at the plug end, or at the end which terminates within your AtS(auto transfer switch)box...

if not, check your own Main Panels' 50amp double-pole breaker, and see if one of the incoming wires to either side is loose.


just an FYI, your 50amp service is TWO different 50amp incoming lines - so when you have 'some' things working, and some thing NOT, it's evident that you have lost power from one of those lines... your main panel is 'split' with some breakers on one hot line, some on the other.... your FRONT main a/c unit will be on one side, the REAR a/c unit on the other, which is why ONE works, but not the other...

If you are using a 30amp adapter to the 30amp camgpround outlet, everything is 'working' because the adapter is able to use the power from the 'good' line and share it to both 'sides' of your RV's main panel : )

[gmc]

Originally Posted by TurnerFam

...
If you are using a 30amp adapter to the 30amp camgpround outlet, everything is 'working' because the adapter is able to use the power from the 'good' line and share it to both 'sides' of your RV's main panel : )

I think this would rule out the issue being IN the RV...
The 30amp adapter having everything working says his shore cord, ATS, and breaker panel is fine...

[TurnerFam]

it's true - the 30amps being 'shared' across the two hot legs of the shore cord mean that the cord, the ATS, and the main panel should be o.k., and the suspect feature would then be the Campground's breaker, or outlet wiring.

There are many situations, especially in new/newer RVs, where the factory does not 'tighten' wiring in the RV great enough to overcome the initial travel and power usage, revealing 'loose' wires that eventually cause these same types of issues. Campground power can certainly have the same thing happen after years of usage and wear, especially on the outlet itself.

[chiefd]

Thanks to all. Here is what the meter read 115 on one leg and nothing on the other leg. So it was the pole. Thanks to all for the education.