The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!

Featured:
   

2017 NEC and Related
2017 NEC
Now Available!

   
Recent Posts
Locked rotor, no burnout
by geoff in UK
Today at 02:04 PM
Temporarily feeding a panel...
by Potseal
09/29/16 11:05 PM
Massive power outage South Australia
by Meadow
09/29/16 06:46 AM
short circuit??
by Meadow
09/29/16 06:43 AM
Norwegian power?
by Meadow
09/29/16 06:36 AM
New in the Gallery:
12.5A through 0.75mm flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
HotLine1 11
sparky 10
gfretwell 8
Potseal 7
Vlado 6
Who's Online
1 registered (Webmaster), 310 Guests and 4 Spiders online.
Key: Admin, Global Mod, Mod
Page 1 of 3 1 2 3 >
Topic Options
Rate This Topic
#185298 - 03/08/09 09:32 PM 3 phase well pump
schenimann Offline
Member

Registered: 02/18/08
Posts: 194
Loc: Western North Carolina
A friend is putting in a 3 phase submersible pump. His well is 720ft deep with the pump at about 700 ft. They are concerned about the torque of a large single phase pump twisting the pipe too much. It is only about a 70 foot run to the power source. He only has single phase power, so I assume there is a converter box somewhere. Is it at the well head or at the breaker. He is getting his pump this week so I should know more then, but I am just trying to get ahead and get a little info about previous experience.

Top
Work Gear for Electricians and the Trades

Work Gear for Electricians and the Trades
Work Gear for Electricians and the Trades
Arc Flash Clothing, Gloves, KneePads, Tool Belts, Pouches, Tool Carriers, etc. etc....

#185299 - 03/08/09 09:56 PM Re: 3 phase well pump [Re: schenimann]
renosteinke Offline
Cat Servant
Member

Registered: 01/22/05
Posts: 5300
Loc: Blue Collar Country
Such pumps are usually integral parts of the well casing (pipe). A million mad horses couldn't shake them loose.

Otherwise, get a three-phase pump and feed it through a frequency drive. This will provide a 'soft start' feature.

Top
#185300 - 03/08/09 10:11 PM Re: 3 phase well pump [Re: renosteinke]
frenchelectrican Offline

Member

Registered: 02/06/03
Posts: 938
Loc: Wi/ Paris France { France for ...
Most well I useally run into most will have a " toqure arrester " and with 3 pump you can invest a soft start or VFD so you can able ramp up without putting in the stress on the pipes.

How big the pump it is ?

Merci,Marc
_________________________
Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)


Top
#185302 - 03/09/09 12:49 AM Re: 3 phase well pump [Re: frenchelectrican]
leland Offline
Member

Registered: 08/20/07
Posts: 856
Loc: Lowell area, Ma. USA
Originally Posted By: frenchelectrican
Most well I useally run into most will have a " toqure arrester " and with 3 pump you can invest a soft start or VFD so you can able ramp up without putting in the stress on the pipes.

How big the pump it is ?

Merci,Marc


I'll 2nd the question. how big a pump? and what is it for?

Top
#185305 - 03/09/09 01:43 AM Re: 3 phase well pump [Re: leland]
jraef Offline
Member

Registered: 07/21/04
Posts: 89
Loc: San francisco, CA, USA
Just to clarify, the starting torque of an AC motor is generally the same regardless of being 3 phase or single phase. The only thing that would make a difference in using 3 phase is if you use a VFD as a phase converter. But 700 feet is a long distance for a VFD run, so make sure your motor and VFD will not have issues with that. You may need what is called a Long Line Filter or at the very least, a reactor on the output.
_________________________
JRaef

Top
#185306 - 03/09/09 06:27 AM Re: 3 phase well pump [Re: jraef]
schenimann Offline
Member

Registered: 02/18/08
Posts: 194
Loc: Western North Carolina
It's going to be a 3hp pump. It will be his primary water supply for his house and his livestock. The county is actually helping with the cost so that he can get his animals out of and fence off the creek.

Top
#185309 - 03/09/09 10:22 AM Re: 3 phase well pump [Re: schenimann]
renosteinke Offline
Cat Servant
Member

Registered: 01/22/05
Posts: 5300
Loc: Blue Collar Country
If it's a three phase pump with a single phase supply, you're pretty much required to use a VFD ... problem solved.

Top
#185310 - 03/09/09 10:54 AM Re: 3 phase well pump [Re: renosteinke]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9012
Loc: Estero,Fl,usa
Why is he using a 3p pump? How much water can a cow drink?
_________________________
Greg Fretwell

Top
#185312 - 03/09/09 11:21 AM Re: 3 phase well pump [Re: gfretwell]
renosteinke Offline
Cat Servant
Member

Registered: 01/22/05
Posts: 5300
Loc: Blue Collar Country
Greg, 700 ft. is a pretty good amount of head. I suspect a single phase motor is both a lot more expensive, as well as considerably larger in size.

Incidentally ... wells are the one place I find the corner-grounded delta service.

Top
#185317 - 03/09/09 04:39 PM Re: 3 phase well pump [Re: renosteinke]
LarryC Offline
Member

Registered: 07/05/04
Posts: 775
Loc: Winchester, NH, US
How do you deal with the excellent ground rod you just installed, with respect to lightning strikes? When you bond the power system to the well casing, you just made the rest of your electrical system very attractive to lightning.

Larry C

Top
Page 1 of 3 1 2 3 >



ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals