ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Recent Posts
Do we need grounding?
by gfretwell - 04/06/24 08:32 PM
by tortuga - 03/30/24 07:39 PM
Increasing demand factors in residential
by tortuga - 03/28/24 05:57 PM
Portable generator question
by Steve Miller - 03/19/24 08:50 PM
240V only in a home and NEC?
by dsk - 03/19/24 06:33 AM
New in the Gallery:
This is a new one
This is a new one
by timmp, September 24
Few pics I found
Few pics I found
by timmp, August 15
Who's Online Now
0 members (), 37 guests, and 14 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
#77651 07/07/01 10:46 AM
Joined: Oct 2000
Posts: 5,392
sparky Offline OP
I have been called into a renovation job. There is a submersible well pump served via a 3-wire. Black, Red, Green. There is not the normal residential 4 wire to the typical franklin control ( yellow being inculded for the start cap).

On arrival, the GC had an extention cord (120V) plugged into the 12-2 which was cut from the holding tank. He claims the pump ran.
some motors will run on any voltage

MY Q is, how do i determine the voltage of this pump?
Do some submersibles not need a cap? , or have intergral ones?

Stay up to Code with the Latest NEC:

>> 2023 NEC & Related Reference & Exam Prep
2023 NEC & Related Reference & Study Guides

Pass Your Exam the FIRST TIME with the Latest NEC & Exam Prep

>> 2020 NEC & Related Reference & Study Guides

#77652 07/07/01 04:27 PM
Joined: Oct 2000
Posts: 2,723
Likes: 1
Broom Pusher and

Heck of a situation here!!!

The first few things I would say about attempting to find out the pump's designed voltage would be:

1: Nameplate Amperes - make it pump water through the same size pipe which it's intended to use, then read the amperes with your clamp-on ammeter. Compare this to the rated FLA. In other words, push it near it's designed Horse Power.
This might also in a round-about way reveal the design voltage - such as if the design voltage was 230 VAC and it is connected to 115 VAC, loading it to the FLA will either stall the motor, or trip an overload on the winding.
Seems likely that if the motor is large [physically and HP wise], it would be on the higher voltage.

2: Setting of voltage selection jumper [if any].
Verifying the current setting on this jumper[s] position should answer the design voltage setting.
If two jumpers are used - connecting the windings in Parallel, then it is setup for lower voltage [115 VAC].
If one jumper is used - connecting the windings in Series, then it is setup for higher voltage [230 VAC].
This is only helpful if you can check, or test, the windings' terminations - typically where the motor circuit connections are made, and/or where the start switch can be accessed.

3: If a visual ID of the windings can be made, try to see what size the conductors on the run winding[s]. If smaller than #18, most likely designed for 230 VAC - all though this is kind of a long shot!!!

These items may help you [sure hope they will!!!], but they are not 100% accurate - except maybe the 1st one - whereas the motor would likely stall if trying to pump the rated amount of water, while supplying the motor with 1/2 the rated voltage. This test is something that you should not perform over more than 5 minutes, just incase a thermal overload occurs [windings overheat].

As you said, these typical use Squirrel Cage Induction motors can still run at 1/2 the voltage, under low and even medium load, and seem to be functioning correctly. It's just at the full load, or rated output HP, do things begin to show their ugly face.

** Now on the Q's about the starting Capacitor;
Some Split-Phase type motors of upto 1/3 HP - and possibly even upto 3/4 HP - can be started with just a "Resistance Split-Phase" type scheme. This uses the typical "Start" winding without a Series Capacitor. The Start winding has a larger Resistance to Reactance ratio with the main "Run" winding.
It is very similar in build to the Split-Phase Capacitor Start motor, where it has a "Start" winding placed 90 electrical degrees offset from the main "Run" winding, plus the "Start" winding is controlled via a centrufigal switch.

If the motor does use Capacitors [either for Starting, or for Starting, then Running], they might be located on/in the motor frame or enclosure. The typical Start Capacitor would be rated at 130 VAC max., even if used on a 230 VAC circuit - due to the fact that the Start winding will drop 1/2 the voltage - so the highest voltage possible across the Capacitor would be 115 VAC [when the motor is connected to 230 VAC].
Thing is that the physical size of a Start Capacitor would make it's enclosure very noticable.

One other type of Squirrel Cage Induction motor that might be used, and has no Capacitor [or even a switchable Start winding] would be the Shaded Pole motor.
These motors usualy max out around 1/6 HP, but maybe a few 1/3 - 1/2 HP models are floating around.
They have a typical loaded speed rating of 1450 RPMs, or 3000 RPMs.
Although they could be used for fluid pumps, they are commonly used for Air moving applications [e.g. Fans].

So, to sum it up - Maybe it's designed for 230 VAC, due to the color code [???], but that's not a great way of determining voltage since it's likely a multi-platform cord [can I use that term on power electrical stuff?? [Linked Image]].

Guess that if no nameplate ID is available, the next step would be to pin point it through a series of tests. If you do go this route, contact me for the procedures and numbers.

Maybe [hopefully] another member can offer better suggestions than mine, which will be more accurate [and simpler] than my "Close to Smoke Test" procedures!!!

Sorry I can't give any better, or precise examples [Linked Image]

Scott SET

P.S. Let us know the outcome of this one! It would be a great topic in a "How-To" area
[hint-hint to Bill [Linked Image]].

Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!
#77653 07/07/01 05:39 PM
Joined: Oct 2000
Posts: 5,392
sparky Offline OP
Thank you for your detailed response Scott!

this is somewhat of a cajun setup in the first place, and i am left to be the 'detective'.

There are some clues,

--this is a standard 8" well casing, but it is somewhat cocked at an angle. so this would indicate that there has been some trauma , i.e.-someone backed into it, or it is not quite a kosher artistean in the first place. ( no one drills @ an angle!)

--the static h20 level is above the surrounding ground, so this means that the seal at the bedrock is either no-good, non-existent, or traumatized.

--the 3-wire insinuates a split-phase or shaded pole motor as you have described that does not require the starting tourqe of a 400' deep artesian.

--unfortunatley,there is no name plate on the well housing which could be tracable to state records. getting a motor nameplate would require a plumber to undo the pitless adapter, and heave out the entire deal...

--the triplex is #12, not any bigger, the splice at the well head goes to the same.

---lastly, the holding tanks contacts are seen to break both white & black of the original 12-2

[Linked Image]

#77654 07/08/01 11:55 AM
Joined: Nov 2000
Posts: 2,236
Likes: 1
Mr. Ignorance here again, I've installed quite a few pumps, both submersible and jet-type. I would lay dollars to donuts that it is straight 240V. I've never seen the extra yellow cap wire that you describe, and I'm not familiar with Franklin...

In all of my Pump installs, a 12-2-G fed from a load center goes to a Jct. box converts to THWN in EMT or NM flex, feeds the line side of the pressure switch, and gets converted to the yellow jacketed "pump wire" with red-black-green stripes. From there, the well digger's are responsible.

I have had to troubleshoot the problem where red-black-blue cable was used and the plumbers put black on ground on the pump side, and blue to ground on the panel side... in a $6 Million house!

The pump would run for a few seconds and "short cycle"... It was probably a good thing that the well casing was not bonded to the black wire...

I couldn't figure it out without pulling the pump, though. So you may have to resort to the worst-case-scenario...

If the well has any depth at all, it is almost 99% likely to be 240V... I'm not even aware of a 120V submersible, (probably my lack of info) and I just recently bought a 120V jet-type 1/2 HP for my house which helped to free a circuit up, (and it was only $120!) which was the first of those I've seen around here. (New at Lowes)
My well is shallow, and there is less than 100 feet from my foot valve to the toilet at the end of the line!, so size and HP aren't a concern.

At any rate Steve, I am as unfamiliar with pumps requiring four-wire as you are with them only on a three...

Guess it's the locale?

Residential/Commercial Inspector
5 Star Inspections
Member IAEI
#77655 07/08/01 02:59 PM
Joined: Oct 2000
Posts: 5,392
sparky Offline OP
thanks Virgil;
i guess this was installed by a WV plumber?
anyways, my guess is that it's a 240V pump also. The owner, given the fact that submersibles are $$$ , is making an effort to track down said plumber....

[Linked Image]

#77656 07/08/01 03:26 PM
Joined: Apr 2001
Posts: 21
Franklin Electric has a brief description of two-wire and 3-wire circuits on there website, . I think the yellow wire is the common for both windings, start (red) and run (black).

Phil H

#77657 07/08/01 07:02 PM
Joined: Oct 2000
Posts: 5,392
sparky Offline OP
thank you Phil, this is a real informative link !

[Linked Image]

#77658 07/10/01 02:46 PM
>I would lay dollars to donuts that it is straight 240V.
I agree.

>I've never seen the extra yellow
Must be a regional thing. "All" deep well submersible pumps are 240 V with black-red-yellow triplex conductors, no NM jacket, no EMT. Some folks use as the conduit to the well head the 1" PE water line left over from conversion from Jet pump operation. But the conductors go down the well just strapped to the outside of the waterline.

>the plumbers put black on ground
Sound like the automechanic syndrome again.

Having a stainless-steel pump casing as an electrode is an interesting proposition.
Perhaps they should be designed for that purpose and everyone should run an extra #8 Cu down to the pump for that purpose. Or not. Just kidding. Actually, I don't see the purpose of the ground wire.
It's not like someone will get electrocuted at the bottom of a well.

#77659 07/10/01 03:45 PM
Joined: Oct 2000
Posts: 2,723
Likes: 1
Broom Pusher and
the plumbers put black on ground
Sound like the automechanic syndrome again.

Is there any 12 step programs available for this certain disorder??? [Linked Image]
Would apply to either the installer, or the person injured from the installation [Linked Image]

***And now for something completely different***

I was at one of our Bank Branch Remodel projects this morning for Supervision of subs, plus reference sub EC's and existing for As-Builts [got to leave by 10:00 AM!! 5:00 AM to 10:00 AM = kick back day [Linked Image]]

Anyhow, when I was verifying the existing service[s], got to check out one of the very few, and probably last, 480 volt ungrounded Delta's that I have/will see[n]!!!
This is an old Building - most likely Circa 1945. It has two separate 400 amp 120/240 1 phase 3 wire gear sections, fed from probably two separate 1 phase transformers [not able to verify this, but that was common for the time period on these types of Commercial structures]. The "Power" stuff [ACs, Pumps, etc.] is fed from the above mentioned 480 volt 3 phase 3 wire Delta - which is also a 400 amp section.
Did some voltage tests on it [just for personal interests] and found out it was ungrounded by the way my Wiggy reacted on a L-G test. The Capacitive Coupled circuit was very apparent from the way the Wiggy "Tried" to register a reading.
So I went to the truck and brought in the Digital meter - semi-low loading effect, not a really high input Z meter].
L-L readings swayed from 475 VAC low to 493 VAC high.
L-G readings were 278 VAC low to 345 VAC high.

Wanted to share this extremely important information with all of 'ya!!!

Scott SET

Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!
#77660 07/10/01 05:31 PM
Joined: Oct 2000
Posts: 5,392
sparky Offline OP
interesting, Capacitice Coupling, being that there was rigid to act as one?

oh, the plumber finally showed, about as old as Yoda with similar ear hair...
told me it's a 240V pump and to get some cheese if i was to continue to whine....

so much for any high falootin' diagnostics,i'll be singin' the coulda woulda shoulda's 'til next time.... but i do thank you all for the input
donuts are on me @ break time..

[Linked Image]

oh, Dspark, we're supposed to ground a well, Mass wants it to be a GEC...

Link Copied to Clipboard
Powered by UBB.threads™ PHP Forum Software 7.7.5