Hi there. I'm looking at a single phase 240V well feed that has three #6 conductors, B/R/W, with the white being used as the ground. It's fed in underground plastic pipe, 600' from the MSP. The customer is wanting to change to a 3-phase pump, and I'm wondering if I can just add some ground rods at the well location and steal that white conductor for the third leg? Are there any requirements that the pipe have the ground run in it? THX! -Daniel
No ground wire
- Thread starter earthstar
- Start date
- Status
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Let’s do the math on a ground rod, 25 ohms, 240 volts, what is the current to ground if the motor shorts? Will the breaker open?
Dsg319
Senior Member
- Location
- West Virginia
- Occupation
- Wv Master “lectrician”
A connection to Earth ground in and of itself doesn’t clear faults and act as an EGC. You’ll have to pull another conductor no way around it.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Yes each branch circuit is required to have an EGC run with the ungrounded conductors. You'll need 4 conductors in a PVC raceway for a 3Ø branch circuit.
Buck Parrish
Senior Member
- Location
- NC & IN
And while you're at it bond the metal casing of the well. As it makes an excellent grounding electrode. ( I'm told )
texie
Senior Member
- Location
- Fort Collins, Colorado
- Occupation
- Electrician, Contractor, Inspector
This is not optional. Metallic well casings must be connected to the EGC. See 250.112(M). There have been deaths over the years due to unbonded well casings. All modern well casing caps have provision for this.
I just hope the diameter of the 600' plastic pipe is large enough to accommodate another conductor. Is it legal to run the grounding conductor outside the pipe, maybe even direct burial of solid bare copper, (just throwing ideas at the wall to see if they stick).
I was thinking the same thing, but then he wouldn't be a customer.
Many times the customer just needs to be informed of the best option and is appreciative of the help, you will not loose a customer. On the other hand not advising them and then another EC comes along and does will most likely loose the customer
ptonsparky
Tom
- Occupation
- EC - retired
Use phase conversion equipment. Rotary or static. Or a VFD that allows single phase input. Common enough methods with the VFD adding capabilities. Not cheap but very doable.
eta: Place the equipment at the well.
eta: Place the equipment at the well.
What would the cost be compared to running a new wire, or in the case the pipe is too small, running a larger plastic pipe?
More importantly, are the existing conductors sized to handle new 3 phase pump and the conversion equipment?
ptonsparky
Tom
- Occupation
- EC - retired
Depends on those pesky details we don't have.
Were the conductors oversized for VD?
What HP does he want vs what he had?
#6 for 600' indicates a pretty small set up.
OP pulls new conductors, keeps it as is, or adds phase conversion.
I don't know if it's compliment, but I still think the cheapest way would be to steal the white wire and make it a phase leg, then run a direct burial 6AWG bare copper for the grounding conductor
- Location
- New Jersey
- Occupation
- Journeyman Electrician
What code section would allow you to run 600' of bare conductor outside of the raceway for the EGC?
ptonsparky
Tom
- Occupation
- EC - retired
We really need to know which one would not allow it, otherwise by default it is allowed
wwhitney
Senior Member
- Location
- Berkeley, CA
- Occupation
- Retired
300.3(B)(3). The OP specified a "plastic pipe", so sounds like a non-ferrous wiring method.
Cheers, Wayne
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Wouldn't the new conductor also have to be installed to qualify as a GEC?
ptonsparky
Tom
- Occupation
- EC - retired
Why would it? (I don't understand the question)
- Status