50 Amp to Welder outlet

[jkwilson]

Voltage in this scenario would have exceeded 134 volts and the Watchdog would tripcthe contactor and zhut power off to the rig. You'd have a bright red face.

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No. Voltage would be normal. Each hot on a 240V circuit is 120V relative to ground and neutral. The system would be triggered by a missing neutral, missing ground or the ground-neutral bond.

[Ranchertx]

I had a welding outlet in my shop and replaced it with a 4 prong 50 amp rv plug. I found a 50 amp to 3 prong welding plug adapter so I can still use my welder when needed.

[Chuck.N]

Hello,
I am at my brother-in-law's place and he has a Welder 3-prong outlet box, which doesn't match my 4-prong 50 Amp cable.
But we exchanged that outlet box for a 4-prong that will plug in. However, (without it being plugged into the RV end), my Power Surge Protector lit up an Error indicating the 'Neutral wire' was missing.
...What should we do now?

Thanks, Craig E.

We recently (earlier this week) ran into the exact same issue. What we did was build an adapter cable assembly with the 3 prong on one end, and 4 prong 50A female on the other. The standard 3 prong connection is used: hot 1 to hot 1, hot 2 to hot 2, and neutral to neutral.

On the 4 prong end, install a jumper wire between the ground and neutral connections, effectively shorting the neutral to ground. Make sure it's heavy enough gauge to handle 30A of current. Without connecting to your EMS, measure across the 2 hot leads. You should get around 230VAC. measuring from either hot lead to ground and/or neutral should yield about 120VAC. Again, do this before connecting to your EMS!

If it measures correctly, connect only to your EMS. You should get the required readings, and no errors on your EMS, and should be save to use.

Disclaimer: this method worked for us, but may not work for you. YMMV. If in doubt, call an electrician.

[BobLandry]

There is NOT any 220 V use in a 50 amp RV Circuit. It would destroy every electrical appliance in the rig and more.

I'm quite aware of that. It is 220V up to the converter where it is splits into the two 110V legs

[A.Texas.Yankee]

No. Voltage would be normal. Each hot on a 240V circuit is 120V relative to ground and neutral. The system would be triggered by a missing neutral, missing ground or the ground-neutral bond.

I understand that, but I was under impression Watchdog caught the single phase as it monitors both legs and would see the voltage exceed 134 overall. I guess it only monitors each leg and doesn't look for split phase vs single phase set ups.

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[xrated]

I had a welding outlet in my shop and replaced it with a 4 prong 50 amp rv plug. I found a 50 amp to 3 prong welding plug adapter so I can still use my welder when needed.

Unless you rewired the wiring coming to the welder recept to have 4 wires instead of three, you are using the ground wire as a neutral.....which is completely against electrical code and is a very dangerous way of doing things. The ground conductor....which is what the original recept had (two hot leads and a ground) should NEVER BE a current carrying conductor. It's only purpose is for providing a path of current flow in case of an electrical fault.

[jkwilson]

I understand that, but I was under impression Watchdog caught the single phase as it monitors both legs and would see the voltage exceed 134 overall. I guess it only monitors each leg and doesn't look for split phase vs single phase set ups.

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The voltage between the hots on any electrical service is always 240V unless an RV pedestal or adapter is feeding both legs of the RV from a single hot, then it would be zero. You will never see any other voltage between hots barring an electrical service problem. 50A RV service is 240V, so the EMS isn’t going to alarm because of that. 120V is only available from either of the hots to neutral or ground, and that measurement is what an EMS looks at. Since neutral and ground are connected to the transformer center tap, they are always 120V from either hot.

[Ranchertx]

Unless you rewired the wiring coming to the welder recept to have 4 wires instead of three, you are using the ground wire as a neutral.....which is completely against electrical code and is a very dangerous way of doing things. The ground conductor....which is what the original recept had (two hot leads and a ground) should NEVER BE a current carrying conductor. It's only purpose is for providing a path of current flow in case of an electrical fault.

The plug was right next to the breaker. I had room for two 120v breakers and it already had a neutral and ground wire there so re-wiring was easy.
I didn’t add a 50 amp plug and keep the 220v welder plug because I did not have room to add the breakers.
So I made it work rather than buy a whole new box.

[Grand Master IceMan]

No. Voltage would be normal. Each hot on a 240V circuit is 120V relative to ground and neutral. The system would be triggered by a missing neutral, missing ground or the ground-neutral bond.

OK, so the Watchdog EPO (aka EMS) should (is designed to) catch a fault if it occurs from the Ground to Neutral wiring..?

And yes, I understand this re-wiring is not ideal ,and is not to "Code"; but I have only 3 weeks left at this location, and if the Watchdog EPO/EMS will do its job until then and keep me and my electronics safe, then perhaps this is the workaround that works best for my situation right now..?

[xrated]

The voltage between the hots on any electrical service is always 240V unless an RV pedestal or adapter is feeding both legs of the RV from a single hot, then it would be zero. You will never see any other voltage between hots barring an electrical service problem. 50A RV service is 240V, so the EMS isn’t going to alarm because of that. 120V is only available from either of the hots to neutral or ground, and that measurement is what an EMS looks at. Since neutral and ground are connected to the transformer center tap, they are always 120V from either hot.

I'm going to muddy up the water a bit here. I have never personally seen this, but I wasn't necessarily looking for it either. I've heard this for the last couple of years, that there are RV parks (newer ones being built) that are now using 208 3phase Wye from the transformers that provide power to the pedestals at their campgrounds. Has anyone here....who actually knows what I'm talking about, seen that scenario? On that power pedestal, you would read the following voltages. L1 to neutral 120VAC, L2 to neutral 120VAC and then from L1 to L2 the reading would be 208. Anyone seen it out there. Most folks wouldn't ever notice it unless they use a meter and test voltage before they plug into the pedestal power, and got 208 instead of the more normal voltages seen with a Split phase system of 230-240V