Motor Question

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dereckbc

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Location
Plano, TX
Was helping a friend installing some solar panels, batteries inverter etc.. for backup power to a well pump. The pump is 3/4 HP 230 volt. Question is why does the motor have a 4-wire circuit with a neutral? What am I missing? Controls operating 120 or starter winding?
 

Dennis Alwon

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Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
dereckbc said:
Was helping a friend installing some solar panels, batteries inverter etc.. for backup power to a well pump. The pump is 3/4 HP 230 volt. Question is why does the motor have a 4-wire circuit with a neutral? What am I missing? Controls operating 120 or starter winding?

Is this a special pump designed for solar hookups. Most solar arrays only produce 110 volts unless, of course, you buy another inverter. Could it be that the pump is designed for either 120 or 240v.
 

cadpoint

Senior Member
Location
Durham, NC
You sure it not a split phase motor ?

induction6.jpg
 

nakulak

Senior Member
I would suggest reading the nameplate and/or literature that came with the motor. a lot of motors are designed for many voltages
 

acrwc10

Master Code Professional
Location
CA
Occupation
Building inspector
nakulak said:
I would suggest reading the nameplate and/or literature that came with the motor. a lot of motors are designed for many voltages

Now why would you want to read the instructions ? That takes the challenge out of the job.
 

dereckbc

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Location
Plano, TX
Dennis Alwon said:
Is this a special pump designed for solar hookups.
Nope, just someone that got stuck without power for a couple of week after a Hurricane. Tried my best to convince him to use a generator rather than solar for standby power.
 

dereckbc

Moderator
Staff member
Location
Plano, TX
nakulak said:
I would suggest reading the nameplate and/or literature that came with the motor. a lot of motors are designed for many voltages
With I could but the pump is in the ground, and the guy threw away the manual. Only clue I have is 4-wires going down the hole and meter confirms voltages of 240/120
 

augie47

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Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
many of the older submersible pumps in this area have a 4 wire cable with a "startter-control" box seperate from the pump. The "start" and "run" caps as well as a start realy and OL protection are in the control box
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
augie47 said:
many of the older submersible pumps in this area have a 4 wire cable with a "startter-control" box seperate from the pump. The "start" and "run" caps as well as a start realy and OL protection are in the control box

Yes but that doesn't have a neutral. Usually it's a yellow black and red wire. Not a white wire, at least not around this area. One is common , another is the starting cap then the running cap.
 

dereckbc

Moderator
Staff member
Location
Plano, TX
Dennis Alwon said:
Yes but that doesn't have a neutral. Usually it's a yellow black and red wire. Not a white wire, at least not around this area. One is common , another is the starting cap then the running cap.
I thought this initially but the wire colors are Black, Black, White, and Green. Volt meter confirms 240/120. That is where I am confused as to why a 230 motor needs a neutral.
 

dereckbc

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Staff member
Location
Plano, TX
tom baker said:
Yes I agree with the above, single phase sub motors will have a yellow lead for the control box, this is for the start run capacitor.
Ok guys start-run makes since. Could it be the EC did not follow color code? The wiring going down the hole is from the controller.
 

Dennis Alwon

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Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
dereckbc said:
Ok guys start-run makes since. Could it be the EC did not follow color code? The wiring going down the hole is from the controller.

That's what I was thinking. I was also wondering how you knew it was a neutral? Teach me something.
 

brian john

Senior Member
Location
Leesburg, VA
Many larger motors will have a thermal cutout. MAYBE?

Literature in this day and age with Part No. a web search should allow easy access to the manufacture.
 

dereckbc

Moderator
Staff member
Location
Plano, TX
brian john said:
Literature in this day and age with Part No. a web search should allow easy access to the manufacture.
Yes I know but the pump is 200 feet down under and the bone-head owner threw away the owners manual. :D
 

acrwc10

Master Code Professional
Location
CA
Occupation
Building inspector
dereckbc said:
Yes I know but the pump is 200 feet down under and the bone-head owner threw away the owners manual. :D

Does he remember anything like , where he bought it ? or have a receipt for it maybe the supplier could enlighten you. Just a shot in the dark.
 
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