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New Well Pump wiring

6K views 28 replies 10 participants last post by  k_buz 
#1 · (Edited)
We have just had a new well drilled. The wiring requirements given by the pump installer were a two-pole 30 amp breaker, and since it's about 200 ft. from the main panel, we've upped the conductor to #8-2 UF with ground. This is, I'm guessing fine for a direct 220v connection (two hots and a ground).

However, I will be building a well house around the pump and tank and have considered installing a small subpanel to add single 110v circuit for a light and pipe heater.

My question is this: Since the grounding bar for the sub-panel will be isolated from the neutral bar can I use the bare copper ground from the main panel as the neutral since the grounding bar will be bonded to a grounding rod at the subpanel? I would probably wrap the bare ground with insulating tape so it would not make contact with the subpanel box.

8-2 UF is about half the price of 8-3 UF...I'd like to save money, but I dont' want to be stupid about it.
 
#6 ·
We have just had a new well drilled. The wiring requirements given by the pump installer were a two-pole 30 amp breaker, and since it's about 200 ft. from the main panel, we've upped the conductor to #8-2 UF with ground.

I dont think I would let a well pump installer tell me how to size the breaker or wire...
 
#18 ·
Just spend few minuites to study this diagram from our good member which he posted quite few time so this will show you the correct legit way.




That will clear up the question what ya hitting at it.

Please do run the proper type conductors to the subpanel this is the safest methold and I know you mention unused ground conductor just look at the diagram you will see why it is USED all the time!

Merci,
Marc
 
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#29 ·
You will need a subpanel. There is no way around it. Thus, you will need to follow all the codes pertaining to subpanels installed in detached buildings. You cannot pull a 8-2 UF and a separate wire for the neutral.

You will either need to purchase 8-3 UF or conduit and THHN/THWN. For your information most THHN is dual rated THHN/THWN. Where are you getting your supplies from. They SHOULD be able to tell you this.
 
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#3 ·
I bet conduit and individual wires will be cheaper than uf, or at least equal and allow options for the future.

Oh yea, what the mad scientist said about needing the 3 cond. and ground.
 
#5 · (Edited)
We have just had a new well drilled. The wiring requirements given by the pump installer were a two-pole 30 amp breaker, and since it's about 200 ft. from the main panel, we've upped the conductor to #8-2 UF with ground. This is, I'm guessing fine for a direct 220v connection (two hots and a ground).

What is the HP of the pump?

#8 AWG with a 1/2 HP pump can be used up to 1610' with proper voltage drop... :laughing:

7 1/2 HP pump maxes out at 200' with # 8AWG., just to give you a little perspective on your wire selection choice.
 
#10 · (Edited)
However, I will be building a well house around the pump and tank and have considered installing a small subpanel to add single 110v circuit for a light and pipe heater.
So if you did this, would the light only turn on when the well was running? :) What i'm asking is, where are the pump controls located? At the pump house?
 
#11 ·
So if you did this, would the light only turn on when the well was running? :) What i'm asking is, where are the pump controls located?
They'll be attached to the wall of the well house, I'm guessing.

I'm talking about a separate 110v circuit off of a subpanel. I have the wiring for the pump (to be installed next week) It will be laying on top of the ground until I get my plumber in here to trench and connect the well to my plumbing. I'm going to then place the electrical conduit with the requisite wire in the same trench.

I was just wondering if I could use the bare ground for the neutral since it would not be bonded to the ground at the subpanel. Obviously, it will need to be insulated to keep it from touching the sides of the box enclosure. I thought maybe I could have a section of insulated #10 wire pig-tailed to the ground in a non-conductive junction box outside of the subpanel. Then have the insulated wire entering the subpanel attached to the isolated neutral bar. The other end of the bare ground is going to the grounding/neutral bar in the main panel where both grounds and neutrals terminate anyway.
 
#17 ·
Randell Tarin, what you are proposing to do is simply wrong. It's against code, there is no debating that. I see no reason to voluntarily break the code (and the law) to save a couple bucks in this situation. As said earlier, you can save a bit on using a smaller gauge wire.

Just for the sake of discussion, if I understand what you proposed to do correctly, the situation between your house and the well house won't be any different than the situation between your house and your neighbor's house that are on the same transformer. But in the end, it's still against code. I've learned that sometimes it's a waste of time trying to rationalize the code, it's best to just follow it.
 
#21 ·
if you really don't want to put in a neutral, you could put in a transformer. It would take the 220 to 110. But think about the future. Perhaps it would be a good idea to put in external gfcis for power tools, whatever, but it wouldnt be worth it to run those off of a transformer. That said, you can get some lights that take 220, and I'm sure you could find a heater that takes 220. But in the long run you'd be better off with a neutral.
 
#22 ·
Will code allow me to do either of these two things:

(1) Can I run a single strand of white #8 (rated for wet locations) in the same conduit as the #8-2 w/g AWG UF to serve as the neutral? OR
(2) Can I run #14AWG UF in the same conduit as the 8-2 and just forgo a subpanel altogether? The difference in costs from doing this to upgrading to #8-3 AWG UF is about $300.

I just want to have a single 110 circuit for possibly a light and a plug for an electric pipe wrap during the winter.
 
#27 ·
I think if he contacts the inspector and asks they may allow the white run seperate as long as the conduit is terminated at the panels and not just inside the wall and free aired. It would be a hack job to be sure but it may pass as technically they're all in the same raceway. If this is ok'd why not use your 8/3 for a 30 sub panel. Your pump isn't going to draw anywhere near 30 amps. At 2hp it will be around 1500w or so. This will leave room for a light and plug. Seperate grounding will be required as you mention.

The reasoning behind not using the bare ground as a neutral is that it becomes current carrying. This could seriously injure or kill someone. Your talking current of probably 12a with the pump running. You can't just tape it. Wire insulation has a certain dielectric rating, this is what gives its voltage rating. You would need to put enough tape on it to give it the rating of an insulated wire. This is not possible where the cable is inside the sheath. Ie: 600v wire needs enough dielectric material to stop 600v from "jumping" through it. It's a poor explanation, but best I can do while half asleep lol.
 
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