3 wires for well pump - all black
#1
Member
Thread Starter
3 wires for well pump - all black
I've got a well pump that had wires cut/disconnected without labelling. The 3 wires are all black. How do I figure out which is which to splice it back to the motor control.
I can't easily do a continuity test since the splice point is 75m away from the motor control.
I can't easily do a continuity test since the splice point is 75m away from the motor control.
#2
You have to do a continuity check.
Are the connection points labeled at the control ?
They should be something like S (start) R (run) C (common).
This must be done first.
Splice all three wires.
Go to pump control and disconnect the three wires.
Label the three wires A, B, C.
A-B= ohms ?
A-C= ohms ?
B-C= ohms ?
Post what you measure and we can tell you which wire is which.
Are the connection points labeled at the control ?
They should be something like S (start) R (run) C (common).
This must be done first.
Splice all three wires.
Go to pump control and disconnect the three wires.
Label the three wires A, B, C.
A-B= ohms ?
A-C= ohms ?
B-C= ohms ?
Post what you measure and we can tell you which wire is which.
#3
Member
Thread Starter
Splice all 3 together at the cut point near the pump?
The wires are twisted the entire 75m length and buried so even if I know what they are at the control, if they're spliced at the other end, then I still need to figure out
A) which of the 3 is which from the source wire
B) which of the 3 is which on the pump
then splice those.
all the wires on the pump are black as well. Not sure which of the 3 to splice to the 3 from the control.
In the image c=control, p=pump
What's the background to the ohm test by the way? If I disconnect all the 3 wires at the control then why will the ohms be different. They're just 3 wires spliced together then?
Edit: I see what you mean. Splice the cut point and then test and the motor will show different resistances?
The wires are twisted the entire 75m length and buried so even if I know what they are at the control, if they're spliced at the other end, then I still need to figure out
A) which of the 3 is which from the source wire
B) which of the 3 is which on the pump
then splice those.
all the wires on the pump are black as well. Not sure which of the 3 to splice to the 3 from the control.
In the image c=control, p=pump
What's the background to the ohm test by the way? If I disconnect all the 3 wires at the control then why will the ohms be different. They're just 3 wires spliced together then?
Edit: I see what you mean. Splice the cut point and then test and the motor will show different resistances?
Last edited by qwertyjjj; 05-19-18 at 05:34 PM.
#5
Splice the cut point and then test and the motor will show different resistances?
#6
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If you simply want to identify the three leads then after marking the leads on either side of any splice cut them so each lead is free at each end. Connect a battery to two of the three leads, any battery will work. Go to the other end and test pairs with a suitable voltmeter based on the battery voltage until you identify the lead connected to the red probe of the meter as displaying a positive voltage from the battery. The lead connected to the black probe of the meter will be the negative battery connection and the unconnected lead will be the lead unconnected at both ends. Permanently mark the three leads with the same number,number, letter or symbol at each end, i.e. mark the lead connected to battery plus with a 1 or A or + and the lead connected to the meter red probe with the same number, letter or symbol. Do the same for the second lead using a 2 or B or - and then the third lead use 3 or C or something on both ends.
#7
The three wires got cut midway between the submersible pump and the controller
and they are all black.
and they are all black.
#9
Member
Thread Starter
I spliced them and am trying the resistance trea at the control box
My ohmmeter just jumps all over the place so I can't get a consistent reading between any of the 3 wires
. It's measuring AC voltage correctly so seems to be working unless the ohm setting needs a fresh battery.
Is there anyway to trial and error the wires or will it burn the motor?
My ohmmeter just jumps all over the place so I can't get a consistent reading between any of the 3 wires
. It's measuring AC voltage correctly so seems to be working unless the ohm setting needs a fresh battery.
Is there anyway to trial and error the wires or will it burn the motor?
#10
Go to the lowest ohm scale. Usually Rx1. Make sure the meter zeroes out when you touch the leads together. If not.... change the battery.
You cannot guess by randomly connecting voltage without possible motor damage.
You cannot guess by randomly connecting voltage without possible motor damage.