Electrical questions, 50 amp service?

[RV Manager]

I am hook up a campground in Ky, brrr it is cold here. Anyway, I am plugged into the campgrounds 50 amp receptacle but my power panel inside the coach says I am only receiving 30 amps. The campgrounds electrician says their service is OK, it must be my issue.
When I run my generator I can power everything I want, but on shore power my system starts shutting things down as soon as I exceed 30 amps.
I contend it is a problem with the campgrounds service but they say no. Thoughts, ideas I can check

[MSHappyCampers]

It sure sounds like a CG problem to me, but you will have to use a voltmeter to check the 50A outlet on the pedestal. You should read 120VAC from common to each hot leg. If you don't have a meter maybe you can get the maintenance man to do the test while you watch.

Good luck, happy trails, and God bless!

[Mr_D]

OP, is your rig wired for 50 amp service or are you using an adapter from a 30 amp cord to a 50 amp plug?

[Lt Dan]

Originally Posted by Catcoach

I am hook up a campground in Ky, brrr it is cold here. Anyway, I am plugged into the campgrounds 50 amp receptacle but my power panel inside the coach says I am only receiving 30 amps. The campgrounds electrician says their service is OK, it must be my issue.
When I run my generator I can power everything I want, but on shore power my system starts shutting things down as soon as I exceed 30 amps.
I contend it is a problem with the campgrounds service but they say no. Thoughts, ideas I can check

If you have the Powerline EMS like my Itasca and it is showing amperage, then you are only receiving 30 amp service. When you are hooked up to 50 amp service, which is in reality 50amp 240v service, the Powerline does not display amperage draw. Only when it is plugged into single leg 120v service does it display and start shedding appliances.

Is your rig set up for 50 amp service? My Itasca was only 30 amp until I converted it to 50 amp three years ago.

If you have a three prong shore power plug, then you only have 30 amp service and it doesn't matter if you are plugged into a 50 amp pedestal or not, you are limited to 30 amps. If you have 50 amp service, then you will have a four prong plug on a heavier cable.

You can check the CGs power pedestal as below. From one leg to the other should be 240v. From each leg to neutral should be 120v. If you get 0 voltage between the two legs, then the pedestal is miswired.

[Chuck48]

Cat coach,
I am going to assume you have a 50 amp coach plugged into a 50 amp plug at the campground, without using any adaptors. If it is showing a 30 amp input into your coach and showing the amps you are using, the campground power is the problem. MS Happy Camper only gave you half the procedure to determine if the power is correct. With your tester check at the power pedistle, you should have 120 between either hot leg and either neutral or ground, and 240 between the two hot legs. If your tester shows 0 between the two hot legs the power is not wired correctly, it is what is called out of phase or each hot leg must be from an opposite phase in the campground panel. This is not a common problem, but it happens. Check the power pedistle, I believe the problem is there. Good luck!

[Steve Ownby]

Originally Posted by Catcoach

I am hook up a campground in Ky, brrr it is cold here. Anyway, I am plugged into the campgrounds 50 amp receptacle but my power panel inside the coach says I am only receiving 30 amps. The campgrounds electrician says their service is OK, it must be my issue.
When I run my generator I can power everything I want, but on shore power my system starts shutting things down as soon as I exceed 30 amps.
I contend it is a problem with the campgrounds service but they say no. Thoughts, ideas I can check

At the pedestal, check for VAC between the hots. You should read 240 VAC more or less. If you read zero then the campground is cheating and both hot legs are on the same phase. This is bad because it can cause too much current to be carried on the neutral. Your EMS sees the zero voltage between the hot legs and assumes 30 amp service because on a properly wired service, that is the only time the hot legs would be on the same phase. This protects your neutral service bit limits you to 30 amps.


Steve Ownby
Full time since '07

[bobmac]

Make sure ALL your circuit breakers are turned on in the main panel. I had turned off the Engine Heater CB for the summer and had the same issue as you are having. Turns out the sense lead for one side of the line was on that circuit. Might not be your problem but thought it was worth sharing - your sense lead could be connected to any of the breakers.

Good luck,

[cbeierl]

Originally Posted by Catcoach

I am hook up a campground in Ky, brrr it is cold here. Anyway, I am plugged into the campgrounds 50 amp receptacle but my power panel inside the coach says I am only receiving 30 amps. The campgrounds electrician says their service is OK, it must be my issue.
When I run my generator I can power everything I want, but on shore power my system starts shutting things down as soon as I exceed 30 amps.
I contend it is a problem with the campgrounds service but they say no. Thoughts, ideas I can check

Make sure that all of your 120V circuit breakers on turned on. The EMS depends on multiple circuits to be able to detect 50A service--in my 2005 Vectra one of those is the washer/dryer circuit. It that breaker is off it will think there is only 30A service.

[Bigd9]

Son of a gun, I was having the same problem as the OP a while back. It suddenly fix itself and I never knew why. But now I do. I had those breakers in the off position and when I switched them on the display was showing 50 amps. I never made that connection till now. Thanks guys.

[wa8yxm]

You really need a multi-meter.

If I ignore the ground it is easier to draw 50 amp service, since one hopes the ground wire carries no current let's do that

This is 30 amp service

Neutral---120 volt--HOT

This is 50 amp servcie

L-1--120 volt--Neutral--120 volt--L-2
L-1- - - - - 240 volt - - - - - - - - - L-2

Your "Service" Computer looks for that 240 volts, if it does not see that voltage it will flag it as 30 amp

(When you plug into 30 amp with a dog bone both legs (L1 & L2) are tied together so they are zero between them)

What can cause what you see.

Blown fuse
Tripped breaker
Defective panel computer or sensor
Bad wire
and the biggie is a bad park supply (Wired with just one hot wire instead of two so the two legs are "Bridged" (like a 30 amp adapter does) behind the panel)

How to test?

Using a multimeter access the connections on the main circuit breakers on your rig, this is a double ganged 50 amp breaker or a double size 50 amp breaker, should be the only 50s there.

CAUTION: DANGEROUS VOLTAGE PRESENT USE CAUTION

Breaker to white wire bus should be 120 volts

Breaker to breaker (The double ganged ones) 240, if both read 120 when measured against the white bus but ZERO to each other,,, Bad park electrician.

If they measure 240 across the pair (anything over 200) problem is inside your RV.

DO NOT TOUCH The metal part of the probe or anything metal inside that box,, ONLY hold the plastic part of the probe.

[NRF]

My Monaco's "power control system" requires that I dial in the correct amperage (20/30/50) on the system. Perhaps this is the problem? I'll have to check what my read-out is when I am plugged into 50 but dialed in at 30. It's always set at 50 since that is all I have ever plugged into.

[RV Manager]

as always thanks for all of the responses. yes, my coach is set up with a 50 amp plug, I have to use an adapter at any campgrd that only has 30 amps. I have checked everything in the coach, all breakers are on etc. The campground I was at before I arrived here was 50 amp and I had no issues so feel confident it is the campgrd plug. I would move, but I am an Amazon Work kamper and they provide the site. Yes, they now have other sites available in other campgrounds but the hassle of moving, etc hooking up my trailer to go 2 or 3 miles is not worth the hassle for what amounts to 4 more weeks as long as I am not hurting my coach.
Yes, I di have a surge protector at the pedestal and it shows both legs being ok.
Thanks for all of the help, if and when it gets a little warmer here and I have the day off I will check everything at the pedestal with my meter.

[wa8yxm]

You can check from inside the RV, just CAREFULLY open the breaker box and mesasure the voltage (Use 250 volt range) between the terminals on the two MAIN breakers, should be 220-240 volt, IF it is zero that's the problem.

[OLYLEN]

Sounds like you have a bad connection in the transfer switch. Try switching the power off and on on the pedestal several times with the power cord plugged in. Second if no joy unplug turn off, ALL POWER INCLUDING BATTERIES, then take cover off transfer switch and tighten all set screws on the power cord side. Also you may find cooked, burnt area, this will be the problem. Good luck

LEN