Need electrical help from someone who knows more than me

[mikeinca]

Which shouldn't be too hard....

I know there are some real electrical experts on here and I'm hoping one of you can help me with a problem I can't figure out. I'm trying to install a NEMA 15-40 4 prong outlet in my garage to power the AC in our Classic. The contactor who replaced our power panel and installed our home solar system left me a junction box with a 4 wire 220 circuit. All I had to do was install the outlet. Simple right? Problem is, it's not working. When I plug in my PT50X surge protector nothing happens. I've tested the PT50X with another outlet and it's working fine.

I'm certain the outlet is wired correctly: Copper ground to ground lug, white wire to neutral, red and black to X and Y. I've also measured voltage both from wire to wire and from lug to lug on the back of the outlet. The readings are the same both ways (as expected) and are as follows:

Ground to Red 120.7 v
Ground to Black 121 v
Red to Black 241.1 v
Neutral to Red 69.7 v
Neutral to Black 50.2 v

The readings I'm not sure about are the ones between the neutral and hot wires. Do they look right? Should they be less than 120V and should they be more or less identical? My only other guess is that there is something physically wrong with the outlet. Otherwise I'm stumped, and this is the last gasp before calling an electrician. Thoughts?

[Al and Missy]

There is something wrong with your neutral. They should read the same as your to-ground measurements. Check the other end of the neutral wire.

Al

[ITSNO60]

Agreed, you don't have a neutral. You are probably using a digital meter and the readings you are getting from H to N are phantom. The neutral may have not been landed on the bus in the panel. Maybe the contractor thought it was like a Tesla which doesn't use the neutral. Still very odd that he didn't land it unless there was no more bus space

[mikeinca]

Originally Posted by Al and Missy

There is something wrong with your neutral. They should read the same as your to-ground measurements. Check the other end of the neutral wire.

Al

Originally Posted by ITSNO60

Agreed, you don't have a neutral. You are probably using a digital meter and the readings you are getting from H to N are phantom. The neutral may have not been landed on the bus in the panel. Maybe the contractor thought it was like a Tesla which doesn't use the neutral. Still very odd that he didn't land it unless there was no more bus space

Aha. Thanks to you both. It's a brand new panel with lots of spare capacity so that's not an excuse. Tomorrow I will check to see if can locate any obvious issue in the panel with the neutral wire and if not I'll get the contractor back out here. Your help is much appreciated!

[GMFL]

Yep that’s it. You have a open neutral.

[rmkrum]

Which guarantees the EMS/surge protector won’t turn on power to the trailer....and that’s a good thing!

Hopefully the electrician did not cut off the neutral lead in the cable. If he did, he owes you a new run connected properly.

This is why I do my own electrical work. Had an ‘experienced’ team of electricians run some heavy three phase power for us at work.

Totally wired it wrong and darn near zapped us before we got out the meter and figured out what they did. They never got invited back the next time we had a project that needed power.

[mikeinca]

Originally Posted by rmkrum

Which guarantees the EMS/surge protector won’t turn on power to the trailer....and that’s a good thing!

Hopefully the electrician did not cut off the neutral lead in the cable. If he did, he owes you a new run connected properly.

I knew I had a problem when I plugged in the EMS and the display wouldn't light up at all. The red, black, and white wires were each capped off with a wire nut in the junction box and appeared to be ready for connection. Seems like it would have been silly to do that with the white wire if it had been cut off, but who knows. Just thinking wishfully, I guess. Hopefully I'll be able to sort it out tomorrow.

[Zil]

Yes. Open neutral. If you are not sure of your electrical skill, stay out of the panel. The original electrician should make it right.

[keweenawbee]

I was at a small campground up in the MN Boundary Waters and felt this weird tingle when I would touch the door of our pop-up trailer. I had my meter with me so I stuck one lead right in the ground and touched the other to the door knob of the camper......120 volts! The campground owner had just built a new cabin between the service and the RV spots and the electrician had reverse connected the feed back out to the camp spots. It was a pretty old resort so I think it had some code problems to begin with.

[gklott]

Originally Posted by mikeinca

The red, black, and white wires were each capped off with a wire nut in the junction box and appeared to be ready for connection..

Make sure your electrician ran 4-wires. You only list 3 wires. Your cable should have black, red, white, AND ground (bare or green). Some electricians think of every 240V circuit in terms of the old clothes dryer branch circuit - which is as you describe.

73/gus

[ITSNO60]

Originally Posted by gklott

Make sure your electrician ran 4-wires. You only list 3 wires. Your cable should have black, red, white, AND ground (bare or green). Some electricians think of every 240V circuit in terms of the old clothes dryer branch circuit - which is as you describe.

73/gus

He mentions the grounding conductor in the first post. (a clue is the mention of the white, red and black wires, 3 conductor cable without a grounding conductor hasn't been available for many years)

For clarity every 240 volt circuit requires only two hots and a ground, always has, always will (well except in the early days the ground wasn't required).
Two hots, a neutral and a ground is actually a 240/120 circuit which is what the 50 amp RV hookup is. Prior to 1996 240/120 circuits to certain appliances were allowed to be fed with a dedicated SEU (service entrance unilateral)cable from the main panel only, it was simply an extension of the main service which shared the neutral and ground in the braided wrap under the jacket of the SEU.
I know of no electricians who do not know and understand this, but I have seen plenty of DIY or handyman installations that didn't understand this. I guess there might be some electricians who don't but then I would be hesitant to call them "electricians"
Incidentally the 3 wire clothes dryer and cooking appliance (240/120) circuits were never legal in mobile homes due to the increased risk of hot skin.

[mikeinca]

Originally Posted by gklott

Make sure your electrician ran 4-wires. You only list 3 wires. Your cable should have black, red, white, AND ground (bare or green). Some electricians think of every 240V circuit in terms of the old clothes dryer branch circuit - which is as you describe.

73/gus

Originally Posted by ITSNO60

He mentions the grounding conductor in the first post. (a clue is the mention of the white, red and black wires, 3 conductor cable without a grounding conductor hasn't been available for many years)

That's correct, 4 wires. Red, black, white, copper ground.

The electrician actually reused the wiring that was originally terminated to an outdoor EV charging station adjacent to my old power panel. He swung one end through the wall to an indoor junction box just a couple of feet away from the old charging station location and then re-terminated the other end in the new power panel. The entire wire run is about 4 feet.

As far as I can tell, it appears all of the connections for that wire are correct in the new panel, including the white wire termination on the bus bar. Maybe somehow the white wire got crimped or broken. I guess I'll have to let him sort it out. It's just frustrating that something like connecting an outlet, that should have been so simple, is now a headache!