My surge protector alerted me to an open neutral on one leg when I plugged into 50 amp tonight. How is that possible, don't they share the same neutral? Testing with a volt meter, it read 120 and 120 on each leg at the plug. Possibly just a bad contact on one legs blade? The surge protector worked fine on a different pedestal this morning and at a different one here in the campground.
I had that at a dilapidated rv park in north Texas. Wires wrong at pedestal. Disconnected and ran off battery and generator. Don't risk it.
Elliot,
I had a similar problem several years ago. Turned out the plug itself had an internal bad connection that was the cause. I replaced it and it fixed the problem (after driving me crazy for a while). The problem was intermittent and depended on the position of the wire entering the plug.
Best of luck.
Len
An open or poorly connected neutral will affect voltage on BOTH hots. One will be above 120 VAC, the other below since there is no "reference" point.
Thanks guys. The owner was trying to tell me it'll be fine but I'm not risking it. They're sending over a maintenance guy this morning. I'm using the 30amp for now. Thankfully my inverter powers one AC so I can still run both off of 30 amps
Elliott, let's think this one through. Your 50A plug teminates a 4-wire power cord. Earth ground, neutral, 120V and 120V.
I'd be checking the terminations on my power cable. Or cables. Especially if I had a molded termination.
Yes, the open/poor neutral could be either shore outlet back to CG breaker box, your cord or connections to your coach surge protector/ATS/main breaker box.
If just a poor connection vs open, it may read just fine under no/light load, but not be able to work under heavy load.
Yes both legs use the same neutral. If it is open for one side it should be open for the other.
What did you use to test when you got 120 on each leg? Were you plugged in when you tested (under load)? When you use a simple VOM meter to test power that uses very little current it can miss high resistance neutrals. Best to use what an electrician calls a wiggy. It is a meter that puts a small load on the circuit when it tests for voltage.
What surge protector told you that? When you have an open neutral in a 120/240V circuit, if the load is inbalanced (one leg drawing more current then the other) you will have one leg with high voltage and the other will have low voltage. Your surge protector may be seeing the low side and they just uses that message. Need to see type of device and what all of it's message are.
Elliot. Since this is the first time it has accrued I would suspect panel first. Isolating neutral issues will hide and be Elusive to find. Most prevalent under a load. You only have one neutral going into your coach so makes me curious if the ground is also playing a part in this and may of just stayed well hidden till now? I would also power down and pick a new position on your power reel just to see if anything changes. May have a brush/slip ring issue in reel? Panel power first.
Scott
I had some intermittant issues with power. Inverter coming on during the night and ACs still running. Both legs full power at pedestal. Sometimes loss of one leg at transfer switch. etc. Finally tracked it down to the power cord reel. Started early on in this trip. Cut the reel out of the circuit, wired power cord to junction after reel. Put the reel in my trunk to examine later. Maybe repairable, the motor still works fine. Will need to drill rivets out of junction box on reel to examine what went wrong. Cost me microwave, coffee maker and a fan in reefer. Consider myself lucky. Find your issue before it goes too far.
I'm using this surge protector: Amazon.com: Progressive Industries 50 Amp Portable RV Smart Surge Protector... (https://www.amazon.com/gp/product/B015Y9A4HU)
I don't think it's my rig. If I unplug my rig from the surge protector and plug ONLY the SP into the pedestal I get the same results; open neutral. If I then carry it over to another pedestal and again only plug in the surge protector, the open neutral warning goes away.
After reading your guys' responses, I suspect the SP is applying a small load to the outlet and that's the reason both our simple VOM meters didn't detect an issue.
So you own the one in the link that has id10T lights? Does this unit have 3 lights on the right and left side? When it reported a problem you had all 3 lights on one side and the other side you had green and blue only on? If this is the case you might ask your question to the manufacture, since it would show up on both sides but it might only report a low voltage and call that on open where the high voltage since they think is ok. This one don't look like this unit will report or stop high or low voltage if both legs are reporting the same.