electric and well question

[loudhornsrule]

I have a well that the pump sits near bottom(40 foot down). Its 900 feet from my electric pole to my water well. I need power. No more generators. What size underground wire do I need to run. Gophers are bad, and my pump is 1/2 horsepower 220 10 gpm. thanks in advance Some different options would be nice

 

[Valveman]

#10 is good to 1020'. Put it in conduit or PVC pipe to keep the gophers out.

 

[Sponsor]

 

[loudhornsrule]

Thanks valveman. Any idea if I can get that in a 1000 foot roll and what it might cost. thanks

 

[Waterwelldude]

You should go with #8 with it that far, #10 will work but is a little light and the wire will get warm. You will lose about 10 to 15 volts by the time it gets to the pump.
With that pump pulling about 6 to 8 amps, it is already at the top of the chart with # 10, if you ever go to put in a larger pump the #8 will give you the room to upgrade.

 

[loudhornsrule]

Thanks waterwelldude. Any ideas what that would cost here in texas.

 

[Texas Wellman]

I agree with WaterWellDude. Go with #8 just to be sure and have peace of mind. Should be able to get a single piece at a supply house, might check with the big box stores. Avoid using splices.

Might look into getting 4-strand wire so you can have a true neutral. With a true neutral you can make a 110V outlet at the well-head for a light etc. 2-hots, 1-gnd, 1-neutral.....

 

[Valveman]

Upsizing wire is not the same as upsizing pipe. A little reduced voltage can be a good thing. It makes a natural soft starter. See the following quote from Franklin Electric, which can also be seen at this link.
http://www.franklin-electric.com/aim-manual/page-36.aspx

“Reduced-voltage starters may not be required if the maximum recommended cable length is used. With maximum recommended cable length there is a 5% voltage drop in the cable at running amps, resulting in about 20% reduction in starting current and about 36% reduction in starting torque compared to having rated voltage at the motor. This may be enough reduction in starting current so that reduced-voltage starters are not required.”

It is from Franklins chart that says a ½ HP is good to 1020’ with #10.
I like tray cable. It is double jacketed, direct burial, sunlight resistant, and I usually get it in 1050’ rolls form the electric supply store.

 

[Ballvalve]

If your low on money 2 # 10's is all you actually need. Pound a ground at the well or ground to the casing if its steel.

I never understand why people don't realize that they make 240v light bulbs - good for those old 2 wire well house lighting issues.

 

[Texas Wellman]

Yeah, I realize they make 230V bulbs....but do they make small, hand-held 240V air compressors? It might be highly convienent to the OP to have a 110V outlet near the well for whatever reason, not just the well...

 

[Justwater]

Pound a ground at the well or ground to the casing if its steel.

http://www.nationaldriller.com/Articles/Feature_Article/5568207104197010VgnVCM100000f932a8c0____

 

[LLigetfa]

When I wired my home, the electrical inspector insisted that I run a #6 bare copper ground from my panel to the well casing.

 

[Justwater]

it was the norm, and alot of places still do it religiously i think. but it has been questioned whether or not it could be related to galvanized pipes rusting out prematurely in certain situations. i've seen alot of steel cased wells rust out that were being used for ground, but i've seen alot rust out without being used as well..

.. i just thought it was interesting and might be a relevant post.


just a thought... i wonder what he would have insisted had your well been PVC

 

[Ballvalve]

http://www.nationaldriller.com/Articles/Feature_Article/5568207104197010VgnVCM100000f932a8c0____

I would not ground a house to the casing - the article is very correct. I suggested he ground his control box and pump to the casing or a driven ground at a remote location. That would not have any potential.

I'll bet a nice zinc anode, like on a boat, bolted to a casing would keep it alive for a century.

They do use anodes on gas lines and oil lines and such, just for that reason.

 

[loudhornsrule]

Thanks for all the valuable info. Very much appreciated.

 

[Gary Slusser]

I wouldn't ground my house to well casing either. When I said that years ago when the code first came out, I was attacked for being against codes... it was only for "safety". While very few if any casings hadn't been grounded for decades and there were many 2 wire pumps (without ground) and no one could relate any injuries because the casings and pumps weren't grounded.