Not per code, but safe?

[junkhound]

Grand-daughter moved into a house with well.

Power to well (circa 1950s or earlier, revised sometme in the past) is 12-2 wg UF wired for 240 V. There appears to be an abandoned MC coming into the well pit but is dead and cannot trace as buried 5 ft deep.

I added red tape to the white wire in the well pit and main breaker box, etc. which had never been done, etc, etc - some other items such as NM in well pit needed correcting etc, etc. Am not going to go to the expense of running 4 wires to the well pit, will leave the 12-2 UF as is.

The other item is that there is a shed another 30 feet away fed with black and white thru 3/4 RMC. The black to black, the white is tied to ground wire in the well pit, and the 3/4 RMC also tied to the 60ft deep 6" well casing so htat is a very solid ground point.

The NON code part is at the shed which uses the UF ground as return, The RMC is tied to the metal box, but the white is treated as a white although the only connection the main breaker panel white in the house is thru the 12-2 WG ground wire.

Other than being not per code, why is this not safe other than being non-standard?

 

[letgomywago]

Only thing I can think that could cause an issue is the UF ground isn't really insulated it has the thick sheath but since it's carrying current you'd want that to have an insulated path from that point on.

I'm for you getting the 4 wires there. Maybe do a 30 or 40 amp subpanel in 1/2 inch rigid to the shed and then re feed the well from that. Having water and live grounds is not ideal.

 

[tom baker]

Only thing I can think that could cause an issue is the UF ground isn't really insulated it has the thick sheath but since it's carrying current you'd want that to have an insulated path from that point on.

I'm for you getting the 4 wires there. Maybe do a 30 or 40 amp subpanel in 1/2 inch rigid to the shed and then re feed the well from that. Having water and live grounds is not ideal.

 

[tom baker]

The UF egc is the same as NM-B, both are listed wiring methods and the non insulation is not an issue

 

[augie47]

I would not be comfortable with it. If for any reason you lost the EGC you stand the chance of energizing the area around the well casing with feed back voltage from the shed.

 

[LarryFine]

Because circuit conductors, including grounded conductors past the service, cannot be bare.

 

[LarryFine]

The UF egc is the same as NM-B, both are listed wiring methods and the non insulation is not an issue

It is when it's being used as the grounded conductor for the 120v extension from the 240v circuit..

 

[wwhitney]

Because circuit conductors, including grounded conductors past the service, cannot be bare.

Do you have the code reference handy? I was looking for it but didn't see it.

Cheers, Wayne

 

[letgomywago]

Do you have the code reference handy? I was looking for it but didn't see it.

Cheers, Wayne

I thought the exception was for SE cables and triplex to have bare nuetrals but that's a separate issue

 

[ptonsparky]

Get back with us when she starts feeling a slight tingle while showering, doing dishes, bathing babies etc. Maybe walking barefooted across damp grass. We will tell you where to start looking.

Put it in PVC.

 

[Joethemechanic]

What's in the shed? Just lights? Make them 240v

 

[tom baker]

The UF egc is the same as NM-B, both are listed wiring methods and the non insulation is not an issue

Sorry I missed the UF egc is current carrying.

 

[Sea Nile]

So if I'm understanding the setup, the shed is being fed from the well. And the shed is using the well pipe as its grounding electrode.

And one of the legs of the 240v well pump is the power for the shed ran through rmc with two conductors, using rmc as the bonding between shed and well casing.

So if a fault occurs in the shed, the effective ground fault return path would be the rmc to the well and then the ground wire of the 240v circuit uf.

And the same ground wire in the uf is carrying the return current of the shed and if anyone removes that ground wire in the panel they can become in series with the circuit.

Other than a ground wire carrying current, you've made two connections to the earth. So in that regard it's similar to having the bonding screw installed in the shutoff of a remote building. (I think that's a violation, not sure off top of head, but I think you don't connect bonding screw at remote buildings due to lightning gradients)

Im not a big fan of the rmc as the ground fault return path either, (assuming its buried and you can't see what condition it's in)

To sum it up, you are one wire (or electrical path) failing away from a dangerous situation.

 

[junkhound]

And the same ground wire in the uf is carrying the return current of the shed and if anyone removes that ground wire in the panel they can become in series with the circuit.

Good point - if they move and resell the property, will siply remove all conductors to the shed. In the meantime, till then, will put white tape on the UF ground wire just in case anyone else gets into the panel <G>

 

[synchro]

What's in the shed? Just lights? Make them 240v

Or provide a separately derived 120V from the 2-wire 240V feed using a transformer.

 

[Sea Nile]

if they move and resell the property, will siply remove all conductors to the shed.

If you remember. You could be suffering from CRS by that time. Better leave yourself a note, maybe tape it to the panel door.

 

[LarryFine]

Other than a ground wire carrying current, you've made two connections to the earth. So in that regard it's similar to having the bonding screw installed in the shutoff of a remote building. (I think that's a violation, not sure off top of head, but I think you don't connect bonding screw at remote buildings due to lightning gradients)

Multiple earthing of grounding conductors is perfectly okay.

A grounded conductor (neutral) should not be bonded again.

 

[tortuga]

Do you have the code reference handy? I was looking for it but didn't see it.

Cheers, Wayne

340.112

 

[LarryFine]

Do you have the code reference handy?

How about 250.24(A)(5), 250.32(B)(1), and 250.142(B)?

 

[Sea Nile]

A grounded conductor (neutral) should not be bonded again.

Exactly my point, the ground of the uf is bonded to the well casing, so electrically the return path of the shed (the defacto neutral) is bonded to the well casing