how to check the windings on a three phase motor?

nwcove

nwcove

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ok, heres what i have. a submersible 3phz 220v 1hp motor. it has four wires coming out of it, black, yellow , green and red. how do i check the windings with an ohm meter?
 
alldodge

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alldodge

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Re: how to check the windings on a three phase motor?

nwcove said:
looked at those, they kinda dont apply .....its a sealed unit ?
Click to expand...

You got me scratching my head. A 3-ph motor is a 3-ph motor, what else can you say about it?
 
nwcove

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Re: how to check the windings on a three phase motor?

thats what i thought too! until all the info i can find is about 6 wire and 9 wire motors. mine has 4.?
 
GA_Boater

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Re: how to check the windings on a three phase motor?

nwcove - Is this for a home pump? Three phase is usually industrial power, not normally used for residential.
 
nwcove

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Re: how to check the windings on a three phase motor?

GA_Boater said:
nwcove - Is this for a home pump? Three phase is usually industrial power, not normally used for residential.
Click to expand...
not a typical residential deep well pump. i bought this thing at an auction for cheap. it was spec'd to large for the application. ( pump curve thing). the dealer would not take it back because there is supposedly nothing wrong with it, i just wanted to check the windings before i tried to re-sell it. just for reference sake, its a myers ,predator plus, st10-12plus-2
 
bigdee

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Re: how to check the windings on a three phase motor?

nwcove said:
thats what i thought too! until all the info i can find is about 6 wire and 9 wire motors. mine has 4.?
Click to expand...

The six and nine lead motors are for dual voltage or star/delta configuration. Yours is a non-configurable THREE lead motor. The green lead is ground. If it is a 3 phase motor resistance will be equal on any 2 leads that you measure(all 3 equal).
A single phase well can also have 4 leads (one is ground and one is common). On a single phase motor the readings between each lead and common will differ because it will have a start winding and a run winding.
 
GA_Boater

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Re: how to check the windings on a three phase motor?

OK - Just wanted to verify.
 
nwcove

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Re: how to check the windings on a three phase motor?

bigdee said:
The six and nine lead motors are for dual voltage or star/delta configuration. Yours is a non-configurable THREE lead motor. The green lead is ground. If it is a 3 phase motor resistance will be equal on any 2 leads that you measure(all 3 equal).
A single phase well can also have 4 leads (one is ground and one is common). On a single phase motor the readings between each lead and common will differ because it will have a start winding and a run winding.
Click to expand...

thanks bigdee! did check for no shorts to ground, and the other three leads ohm out equal.
 
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Re: how to check the windings on a three phase motor?

I'm doubtful it's a 3 phase pump. It's likely a 3 wire pump that requires a capacitor box above ground for operation. This is different from a 2 wire pump which has the start capacitor contained in the pump. This was done to make it easier to change the capacitor if it goes bad. You will need the cap. box to operate the pump.
 
bigdee

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Re: how to check the windings on a three phase motor?

KD4UPL said:
I'm doubtful it's a 3 phase pump. It's likely a 3 wire pump that requires a capacitor box above ground for operation. This is different from a 2 wire pump which has the start capacitor contained in the pump. This was done to make it easier to change the capacitor if it goes bad. You will need the cap. box to operate the pump.
Click to expand...

I have a feeling that you may be correct. If it is single phase there will be a SLIGHT difference in ohms. Check ohms from the black lead which should be common to the red lead and then to the yellow. Then measure from yellow to red and you should see even more resistance. Use the lowest scale on your multimeter and post the results.
 
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nwcove

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Re: how to check the windings on a three phase motor?

100% sure its a three phase pump.
 
bruceb58

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Re: how to check the windings on a three phase motor?

Does it actually say 3 phase on the pump?

You sure this isn't just a 3 wire pump? Not 3 phase?

Red,black and yellow go to a motor control, green is ground for a 3 wire pump.

Have a picture of the pump's label?

This is typical for the wiring of a 3 wire single phase pump
Capture.JPG

If it's 3 phase, red, black yellow are the 3 winding inputs and should read very low ohms to each other.
 
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gm280

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Re: how to check the windings on a three phase motor?

nwcove said:
100% sure its a three phase pump.
Click to expand...

You could take the manufacture and/or the part number and go online to that company and see their winding layout. Most motor companies have that available so folks can see how the motor could work for their situation... Just an idea!
 
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Fishing Dude too

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Re: how to check the windings on a three phase motor?

3 phase would be more than 220, red, black hot, yellow neutral, green ground.
 
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