Welding 50amp Outlet

[Solo_RV_Guy]

Originally Posted by cavie

NO, no, : facepalm:

Ground MUST be bonded at the service entrance

^^THIS, although Code says the bond must be "at the point of service." That could be the meter base or the first service disconnect.


For those interested, it's in Article 250 of the National Electrical Code, NFPA70.

[Unplanned Tourist]

Not saying my idea would be to code.

IF the current ground wire is the same size and insulation as the others, it will work.

Anyone ever been to India or any of many countries in Africa? You would think my suggestion would be super safe compared to that wiring system!

Put a GFI in the sub panel by the 50 amp outlet and be happy.

Happy Glamping.

[Alpine36]

Convert it to 30a with existing.
Anything else is a dig up and new 4 wire svc.
Personally I like easy, and never had the need for 50a at home.

[twinboat]

Keep in mind that converting it to 120 volt 30 amps will mean you can no longer use it as a welder outlet. There will no longer be 240 volts available at that outlet.

[cavie]

Originally Posted by Unplanned

Not saying my idea would be to code.

IF the current ground wire is the same size and insulation as the others, it will work.

Anyone ever been to India or any of many countries in Africa? You would think my suggestion would be super safe compared to that wiring system!

Put a GFI in the sub panel by the 50 amp outlet and be happy.

Happy Glamping.

3rd World Country wiring.

[lwmcguire]

Interesting to follow

Prior to the 90's dependent on what area of the country you were in you didn't find ground wires on anything

Lot of dryers and as mentioned by the OP welder receptacles still in use with three wires and?

In many places based on building dates they are exempt from current codes until renovations

Same goes for GFCI

I am sure many grey beards can remember hot skin tingles on old (new at the time) RV'S

Sure the new and improved circuit wiring has saved a few shocks and maybe worse but we survived a lot of years without the ground wire

Using the properly installed ground rod is certainly a safe option even if it isn't bonded

What about sub panels?

[KanzKran]

A note about ground rods - most normally installed grounding electrodes like ground rods can't pass enough current at 120V to trip even a 15A breaker. In fact, in addition to the prohibition mentioned by others above about the earth not being relied upon to pass fault current to open a breaker (or fuse) to clear the fault, there is a requirement for single electrodes (like a ground rod) to have a resistance to ground of 25 ohms or less, and if not, a second one has to be added at 6 ft spacing or more. And there is no performance requirement for those two rods or other made electrode system at that point.

At 120V, 25 ohms will only pass 4.8A. You could put a live conductor on that rod and do nothing but (maybe) chase a few night crawlers out. And it's difficult to measure the impedance to ground anyway, so most folks just drive a pair of rods and call it good.

Grounding electrodes are there for many reasons, specifically lightning, voltage stabilization, and to hold all things grounded to the same potential as the earth in that immediate vicinity, but working alone as a 'safety ground' is not actually one of them, and the NEC is quite clear on that point and has been since before my time.

[Mudfrog]

From the information at hand, converting to 30 amp service sounds like the best plan. I'll add that if it were me, I'd wrap white electrical tape around both ends of the relocated (from hot to neutral) wire so that there was no mistaking it as now being neutral.

[Full.Monte]

Don't, under any circumstances, connect that 220v plug to your RV. You will start a fire. I think you already know that. Rv's are wired differently. In a 50A system, they use two hots, like in house wiring, but they are connected through a box that separates the two hots so that it is not possible to get 220v power...only two 110v 50A lines.

It is possible to change your existing 30A plug to a 30A RV compatible 120v plug. You would leave the wire attached to the brass screw where it is. That will be your 110v hot. You would remove the wire from the silver screw. This will become your new neutral wire for the 30A 110v service. Now, the code says this must be a white insulation colored wire. You can wrap the wire insulation (inside the box) with white electrical tape to satisfy the code. Then disconnect the same wire from the breaker at the panel. Again, wrap it with white electrical tape in the panel box. (The panel should be turned off for this). Then you will connect this wire to the neutral bus. Now, at the other end, you will have a receptacle that has a hot, a neutral, and a ground. Test each plug terminal with your meter to check that you have 110v from hot to neutral, and 110v from hot to ground. No digging, not much work. You are done!

By the way, you did not say what size you wire is coming into the 3-way wall receptacle. It must be able to carry 30A. If not, then you need to dig and install wire of the correct size or change the plug to a standard 120v receptacle. If you are leaving the RV plugged in just to keep the batteries charged, you may be able to get away with this. If you are planning to use more power, you are back to considering putting in larger gage wire.

FYI...a neutral is a current-carrying wire. It is required to complete a circuit. A ground NEVER carries current unless there is a short somewhere. This was the original idea to protect people from getting shocked or electrocuted.

Good luck. Above all, be careful! If any of this scares you or you aren't comfortable with wiring, you may want to call an electrician.

[twinboat]

Originally Posted by Full.Monte

Rv's are wired differently. In a 50A system, they use two hots, like in house wiring, but they are connected through a box that separates the two hots so that it is not possible to get 220v power...only two 110v 50A lines.

.

A box that seperates the hots ?

Since the neutral is the same gauge as the hots, you can not seperate the hots without adding another neutral. Neutral only carries the difference between the 2 hots, nothing if draw is equal on both.

If you have a 50 amp RV, it will have 2 main breakers. If you measure the voltage between them it will read 240 volts.

http://www.myrv.us/electric/Pg/50amp_Service.htm

[Full.Monte]

Originally Posted by twinboat

A box that seperates the hots ?

Since the neutral is the same gauge as the hots, you can not seperate the hots without adding another neutral. Neutral only carries the difference between the 2 hots, nothing if draw is equal on both.

If you have a 50 amp RV, it will have 2 main breakers. If you measure the voltage between them it will read 240 volts.

The 50-amp 120/240-volt 3 pole 4

The main 50A breaker has two 110v sides to it. Yes, they will measure 220v across the two hot sides of that breaker. But the whole thing is designed so you cannot put two breakers side-by-side to give 220v like you can in house wiring.

Yes, the neutral is the same size as the two hots, but since they are out of phase with each other, the neutral wire will actually be carrying less current than the total current coming through the two hot wires. If you imagine that the two hots were carrying the same current 180 degrees out of phase, there would be no current measured in the neutral wire. Since the wires are not carrying current at 180 degrees phase shift, but 120 degrees, there is some current being carried in the neutral wire, but not zero. From your comment, i think you understand this.

[richard5933]

Originally Posted by Full.Monte

The main 50A breaker has two 110v sides to it. Yes, they will measure 220v across the two hot sides of that breaker. But the whole thing is designed so you cannot put two breakers side-by-side to give 220v like you can in house wiring...

There are RVs which have 240v appliances and 240v circuits. It's not the most common way to do it, but there are those that do. Our first coach had a JennAir grill/range which ran on 240v.

[radar]

Interesting enough Tesla sells an adapter for use with that receptacle. Of course the EVSE/car charger is a balanced 240 volt load. Unlike an RV.

[Full.Monte]

Originally Posted by richard5933

There are RVs which have 240v appliances and 240v circuits. It's not the most common way to do it, but there are those that do. Our first coach had a JennAir grill/range which ran on 240v.

Yes, I've heard that. Those RV's are less common. The RV-style distribution boxes are 120v at each outlet or appliance. I've not had an RV that has 220 volt panel, but where they exist, there wouldn't be much difference from your main house panel. I guess the wisdom here is that you have to understand what you have before you start wiring something that could get you in trouble. That's why I have a Surge Guard to protect me from shade-tree electricians that may have wired the receptacles in RV campgrounds!