Wire to well house question. Electricians?

[roger55]

Currently, I have a small well house 6ftX6ft on the back of my acreage with a 1 HP well pump.
It's a 1 HP pump and when I look up the specs for it, it says to use a 15A breaker. (It's 240V). The wires are run overhead and a couple of poles need replacing. My wife doesn't like the overhead wires and wants me to put them underground in conduit.
I have the trench done by someone but I would do the rest. I just talked to my well driller and he said the charts say to use #6 wire since it's 350 feet from the main breaker panel to the well house sub-panel. He also says he always puts 20A breakers on 1 HP pumps even though they can work with a 15A.

My question:
He says I only need to run 3 wires for a well house. But, shouldn't I run a 4th wire for a ground? If so, should I use a #8 wire for that one and #6 for the other 3? However, their's only 3 conductors with the present overhead aluminum wires.
And btw, the well house has a light inside, one outside and has one standard 120V electical outlet inside as well.

 

[mrb]

you would need 4 wires since you have 120v loads. Whats the outlet for, how much 120v current do you need? I might be inclined to pick up a cheap 1KVA 240-120 transformer to save 350ft of #6...

 

[roger55]

you would need 4 wires since you have 120v loads. Whats the outlet for, how much 120v current do you need? I might be inclined to pick up a cheap 1KVA 240-120 transformer to save 350ft of #6...

Can't I use #8 for the ground wire? I thought it was OK to drop 1 size for the 4th wire. The #6 is .62/ft and the the #8 is .40/ft. I don't know how much a transformer is but I'm looking at $140 for 350ft of #8 (or $217 for #6) extra to run that 4th wire.

The outlet is there for heat tape on the well in the winter. It's also handy in case I need a power drill or something like that. I've used a trouble light out there as well.
Used a small construction compressor out there when I installed new siding on the structure. But if I ever need to run anything again that draws that much, I can turn the well off while I'm using the outlet.

 

[mrb]

Can't I use #8 for the ground wire? I thought it was OK to drop 1 size for the 4th wire. The #6 is .62/ft and the the #8 is .40/ft. I don't know how much a transformer is but I'm looking at $140 for 350ft of #8 (or $217 for #6) extra to run that 4th wire.

The outlet is there for heat tape on the well in the winter. It's also handy in case I need a power drill or something like that. I've used a trouble light out there as well.

I havent done the calculation to see what size ground you need. Its not as simply as being able to drop a size when you are upsizing for voltage drop. It could very well require a #6 for the ground since you are starting with a #12 ground for a 20a circuit, and the size of the ground has to be increased proportionally to the circuit conductors. After reading what I wrote I would say you do infact need a #6 ground.

for 240v only, you would run two hots and a ground. if you need 120v in there, you would run two hots, a neutral, and a ground. Regardless of the size of your ground, the extra wire for the neutral will be a #6 either way.

how many watts does your heat tape draw?

 

[roger55]

I havent done the calculation to see what size ground you need. Its not as simply as being able to drop a size when you are upsizing for voltage drop. It could very well require a #6 for the ground since you are starting with a #12 ground for a 20a circuit, and the size of the ground has to be increased proportionally to the circuit conductors. After reading what I wrote I would say you do infact need a #6 ground.
for 240v only, you would run two hots and a ground. if you need 120v in there, you would run two hots, a neutral, and a ground. Regardless of the size of your ground, the extra wire for the neutral will be a #6 either way.
how many watts does your heat tape draw?

Heat tapes don't draw very much. Just 84 watts for a 12 footer. So, that plus a light inside and a light outside.

 

[Aceman]

3-#4 AL USE with a #8 AL USE ground. 60 amp breaker. 1.25"-1.5" pvc, lube it up and take care not to nick the wire when you pull it.

Aluminum is roughly a third of the cost of copper right now.

 

[roger55]

3-#4 AL USE with a #8 AL USE ground. 60 amp breaker. 1.25"-1.5" pvc, lube it up and take care not to nick the wire when you pull it.
Aluminum is roughly a third of the cost of copper right now.

Thanks for the info.
I'll call the electric supply and price that come Monday.
Why a 60 amp breaker?
Also curious how you determined your recommendation on the size of the ground wire. Is that a code thing or derived from a calculation?

 

[Aceman]

Why a 60 amp breaker?

You need a minimum of #6 copper or #4 aluminum to keep your voltage drop in check. Rather than putting a 20 amp breaker on #4 aluminum and having to deal with upsizing your ground(If you use #4 hots on a 20 amp circuit, you'd also have to use a #4 ground), it's easier to put a 60 amp breaker on it. #4 aluminum USE is rated for 65 amps.

Also curious how you determined your recommendation on the size of the ground wire. Is that a code thing or derived from a calculation?

A 60 amp breaker requires a #8 aluminum ground wire(or #10 copper if that was what we were using). It's straight out of the NEC table 250.122.

Install a small 100 amp main breaker panel in your wellhouse or backfeed a 2 pole 60 amp breaker with a retainer kit in a main lug panel. I like the main breaker panels myself. Drive a couple ground rods at the wellhouse, bond your well casing or water pipe if it's metal above ground.

 

[roger55]

I just called the electric supply place here in town that I usually deal with. I sounded confused about me asking for USE and said for underground in conduit, I need XHHW. He doesn't stock it and would have to order it in. So, he is going to call me back with the price. He said to use copper for the ground. Don't know why he said that. Maybe there's not that much cost difference between #10 copper and #8 AL.

Should I try somewhere else?

 

[Aceman]

U-S-E is a direct burial rated insulation. I like to use it, even in conduit, because it's a little more durable than XHHW IMO. Nothing wrong with XHHW, but since aluminum likes to turn into white chalk once moisture hits it, I like to know the insulation is as durable as possible.

XHHW is usually just a few cents cheaper per foot, but since USE is readily available over here, we spend the little bit extra for the added protection.

To answer your second question, #10 copper would work for your ground wire. There's nothing wrong with aluminum circuit conductors and a copper ground.

Make sure when you order your wire from the supply house that you verify the wire will come on spools and not just rolled up.

 

[roger55]

The first elec. supply place didn't call me back. So, I tried another. Not in stock either. Had to call their supplier to get me a price. She called back with $1.41 per foot. I told her that's gotta be a mistake maybe they got quoted for 4/0. She said no they specifically said that was for #4 Aluminum XHHW. I said check again, it's definitely a mistake. She said OK and then didn't call me back.

I called a third place and they said they would have to order it in but could only get 1,000 rolls. Well, I need 3 X 350 or 1050 ft. So, he said I would have to get 2 rolls and suggested I try elsewhere. I didn't even bother to ask this one about an aluminum ground wire.

Not having too much luck. I guess it's because San Angelo isn't very large.

 

[housey]

Is 240v single phase or 3 phase in America?

 

[roger55]

Border States just called me back (the second place I called). Apologized for the mistake and quoted me $223 (a little over 21 cents per foot) for 1050 feet of #4 XHHW plus a $40 cut charge, plus shipping from Dallas. They can't get the #8 but can get #6 for the ground for $60 plus a $20 cut charge. So, I might as well get the #10 copper for the ground wire as the cost is pretty close and it would be a little easier to work with.

Maybe I could rent or borrow a 500' fish tape. I don't really want to buy one for a one-time job like this.

 

[Aceman]

That sounds better.

You don't want a fish tape. You need to use a shop vac. Tie some mason line/kite string onto the handles of a plastic grocery bag. Shove it into the end of the conduit like a parachute or umbrella, you may need to wad up another plastic bag and stick it inside the one your tied on to. Turn the vac on, it should fly through the pipe.

Use the kite string to pull a larger rope through the conduit, I like mule tape myself(it's a flat rope made for pulling) because it won't burn into the pvc 90's on the end. Make sure you lube the wire up well when you start pulling.

Whatever kind of rope you use, you don't want it to stretch. Nylon rope is terrible for pull rope, it'll burn the 90's and you'll spend all your time stretching it just to get the wire to actually move.

You should be able to google "mule tape" to see what I'm talking about.

 

[rburke65]

At the electrical supplier you can buy a bottle or two of "wire lube" to make your pull easier. Run 2" pvc conduit. Keep the kinks out of the wire, and lube the hell out of the wire. Good luck...you'll be fine.

 

[Gooch]

I don't have my book with me and can't remember the section, but i thought there was a section that required all conductors of the same circuit to be of the same material.

 

[Gooch]

That sounds better.

You don't want a fish tape. You need to use a shop vac. Tie some mason line/kite string onto the handles of a plastic grocery bag. Shove it into the end of the conduit like a parachute or umbrella, you may need to wad up another plastic bag and stick it inside the one your tied on to. Turn the vac on, it should fly through the pipe.

Use the kite string to pull a larger rope through the conduit, I like mule tape myself(it's a flat rope made for pulling) because it won't burn into the pvc 90's on the end. Make sure you lube the wire up well when you start pulling.

Whatever kind of rope you use, you don't want it to stretch. Nylon rope is terrible for pull rope, it'll burn the 90's and you'll spend all your time stretching it just to get the wire to actually move.

You should be able to google "mule tape" to see what I'm talking about.

exact reason that we use rigid factory 90*s underground to keep from burning through the PVC.

 

[Falcon67]

you would need 4 wires since you have 120v loads..

Nah, that's unnecessary code work. You can do what the POs did on the well at our new house - just throw the wire (#12 for this pump) in a ditch and for 120V power to the control just take off one of the hots and tie into the safety ground (copper). Really. And put it in an outdoor outlet box to make it look good.

Don't panic, after I found that it was immediately removed. I can manually operate the sprinkler valves until I get time to run a fresh setup.