Well pump wiring

[EdT]

I have a well that I now use only for outdoor watering. 25+ years ago, it supplied my house. It was set up by "Bubba" the well guy and has never run dry, so it's a good well. The question is that the wiring is only two wires. Two hots giving 240V across the pair. There is no ground. I suppose back in the day that the 50 feet of iron pipe extending into 40 feet of water provided a pretty good ground rod. Problem is, it's plastic pipe and fresh water is not that great a conductor. Running a ground back to the box would be difficult since it's around 100 feet and it's under ground. Would there be any value in installing a local ground rod and connecting to it or just let it be. It's never been a problem, but I don't want it to become one.

 

[bjcouche]

I would think even 25 years ago it should have had a ground, but you did say that it was installed by "bubba". I would just either leave it alone or install a GFI breaker. You should be able to just swap out the existing dual breaker for a GFI one. These are commonly used for hot tubs and such but they are pricey. If it's just for watering the lawn and such that's what I'd do, but if it was the supply for my house I'd make it right.

just my $.02

Brian

 

[kbs2244]

If it is a submersible pump it is grounded better than anything you can do at the surface.

 

[rkevins]

If it is a submersible pump it is grounded better than anything you can do at the surface.

Agreed.......... we have had submersible pumps for 30+ years with plastic/pvc pipe and none of them have a ground wire, some are 2 wire some are 3 wire but no ground

 

[DekeT]

If it is a submersible pump it is grounded better than anything you can do at the surface.

Similar to the gas pipe bonding thread.
http://www.garagejournal.com/forum/showthread.php?t=161626

Is it grounded to the same potential as the house wiring?

 

[sberry]

A ground rod is NOT a substitute for a wire, neither is pipe or casing. Either gfci or dig up as close as you can to the feed wire and run a wire with it.

 

[EdT]

It is not a submersible pump. Above ground jet pump. About 20 years ago, I ran a 60 amp branch circuit to my garage. At that time the inspector wanted a separate ground rod at the garage. Three wires from the house; two hots and the neutral. That's why I was thinking that a ground rod at the well would work OK. It is a bit puzzling to me why running a ground wire from the pump to the ground in the breaker box and then to the ground rod associated with the breaker box is electrically different than a ground rod at the well. Isn't ground ground everywhere?

 

[Stuart in MN]

It is a bit puzzling to me why running a ground wire from the pump to the ground in the breaker box and then to the ground rod associated with the breaker box is electrically different than a ground rod at the well. Isn't ground ground everywhere?

There can be a difference of potential between one ground rod and another located some distance away.

 

[sberry]

It is not a submersible pump. Above ground jet pump. About 20 years ago, I ran a 60 amp branch circuit to my garage. At that time the inspector wanted a separate ground rod at the garage. Three wires from the house; two hots and the neutral. That's why I was thinking that a ground rod at the well would work OK. It is a bit puzzling to me why running a ground wire from the pump to the ground in the breaker box and then to the ground rod associated with the breaker box is electrically different than a ground rod at the well. Isn't ground ground everywhere?

No, the purpose is not the same. When a panel is fed 3 wire like your old one the neutral was bonded to the ground, any fault would be carried back to the service on the neutral wire causing the breaker to trip, this does not happen thru a ground rod, the earth resistance is too high to allow for this to happen. Yes, there is a point to rods, 2 main reasons, one to hopefully carry a lightening strike vs sending it down the wiring and to eliminate some potential differences between the ground you are standing on and everything else in the place, this is not for fault return. This well equipment has the potential to have an issue you are un aware of and have standing 120V,,, not enough current flow though to trip the breaker or blow fuse.

 

[sberry]

Relying on a ground rod is expressly prohibited by the code as a fault return path.

 

[Aceman]

Pull the pump and rewire it with 3 conductor. With a ground all the way back to the panel, driving rods doesn't cut it.

Down the road when the pump starts to fail, one day you might jump in the shower and feel a tingle.....

 

[Gooch]

You need to remember that Electricity does NOT want to go to ground, it wants to return to the source(Neutral or another phase) That means if you drive a ground rod and call that good, if the pump faults, the fault current would need to travel through the earth to the ground rod at the panel, or the utilities transformer and back to the neutral, this is an extreamly high resistance path and would draw very little current thus, not causing the circuit breaker to trip.

You were allowed to run a three wire service to your detached garage but the neutral and ground are(should be) bonded.

 

[EdT]

Aceman: As I get older, feeling a tingle as I jump into the shower might not be all bad.

Sberry, gooch and others: Thanks for taking the time to explain this to me. I think I understand it better now. I will explore the possibility of adding a ground back to the box. Since the wire is in conduit I might be able to pull two wires through with one of the ones that's there. Great if it works, hell to pay if it doesn't. There are several tight bends which make it more of an adventure.

 

[kbs2244]

I have to agree with the need for an above ground pump motor.
You would think that "ground is ground" but it isn't.