Testing Shows all Outlets have "Bad Ground"

What kind of test are you performing that shows a "bad ground"? Are you using a test plug with neon lights? Are you plugged into a shore power plug when you make the test? If so, then maybe the ground connection in the campground power system is bad. Need to know more information.

Keep in mind, the breaker panel in your RV is considered a "sub panel" for NEC purposes. That means the ground and the neutral are not connected together at the RV, nor at the campground power pole. The neutral to ground connection is only made at the campground main breaker panel.

How long since you opened the RV breaker box and tightened all the screws holding wires? A rolling earthquake vibrates wire connections loose quite often. I check mine every year and usually find at least one that tightens a bit.
OF COURSE, DISCONNECT FROM ALL 120VAC POWER FIRST!

Pull the plug around inside and check continuity from the pin to the bus.

Are you using any extension cords OR adaptors ??

larry cad wrote:

Keep in mind, the breaker panel in your RV is considered a "sub panel" for NEC purposes. That means the ground and the neutral are not connected together at the RV, nor at the campground power pole. The neutral to ground connection is only made at the campground main breaker panel.

In addition to this my WFCO WF-8900 Power Distribution Center has a NEUTRAL BUS BAR connection to all NEUTRAL connections and passes this on to the NEUTRAL lead of the shore power cable. This NEUTRAL BUS BAR is isolated from the trailer FRAME ground.

I also have a second GROUND BUS BAR where all of the GROUND CONNECTION from the ROMEX cable feeding everything is tied to and this is passed on to the GROUND wire of the Shore Power Cable. The difference here is the BUS BAR also goes directly to the WF-8900 Chassis Gnd connection which is also going to the trailer frame ground with a solid wire...

You can see this here on this WF-8700 main frame drawing...


This is how the GREEN wire coming from the Shore Power cable goes to the trailer skin frame ground on my trailer...

Roy Ken

If it's at a campground, there may be an open ground at the site. I've had my EMS indicate open ground at several campsites. mostly because the 30A outlets are used a lot, and end up being marginal. In all cases I notified the campground, they came out an looked, and sure enough either the ground from the panel was bad, or the plug was bad.

If it's at your house, then it is more likely that the problem is in the trailer.

Larry Cad - Yes, I'm using 3-light plug-in tester that shows the 6 possibilities. I am plugged into a campground shore power. I asked campground maintenance to test the shore power plug-in. Seems like testing with generator power would be a good idea.
Ray - I did check all of the connections in the breaker box
time2roll - I don't understand " Pull the plug around inside ..."

OK so most test meters have short leads. Remove the cord from the pedestal. Bring it around to the front door or inside next to the breaker panel. Use the meter to measure ohms from the ground pin of the plug to the ground bus in the RV. Value should be very close to zero. Hopefully it reaches around far enough inside so that it is easy to check.

if you have an ON Board built in generator

testing with genny on, shore unplugged, may show a different result

testing with a 'portable' generator often shows open ground those test lights
because the neutral is bonded in the generator

Use a 30/20 adapter and test the pedestal with you house hold tester. Testing the pedestal before you plug in is a good safety precaution.

I've found reverse polarity and open grounds on 30A pedestals.