trying to wire an old electric motor on a toledo threader. has 4 wires that test with continuity between 2 pairs. motor has six brushes and operates forward and reverse. we have a 3 pole double throw switch to operate this with jumpers across posts. this motor does not have a cap or cent. switch. any idea how to wire or where to find a diagram. thanks for any help.

 

It is possibly a 3-phase Y connected motor. See here for the different types. You can differentiate between the types with an ohmmeter. John

 

But why would it have six brushes when you'd normally only expect three on a three phase motor?

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3 phase motors with brushes are not common devices, and there are all sorts of ways of wiring them up. PPINC didn't say anything about 3 phase. The only thing he mentioned that was a multiple of 3 was the brushes.

What is the voltage of the motor?

How are the 6 brushes arranged?

Any other information and a photo would be a big help.

 

The motor is 115 volts and can be operated ac or dc. The current use for the motor is on a pipe threader. the switch configuration is as follows.
1 2 3
4 5 6
7 8 9
There is a jumper from 1 to 8, from 2 to 7, and from 3 to 9. There is evidence of wires being hooked up to 1,2,3,4,5,6 but no wires to 7,8,9.

Also the six brushes are arranged around the case evenly spaced with 3 brushes used by each pair of wires from the motor.

Thank you for the replies.

 

It looks like it is a series-wound motor. That is just about the only type of motor that will run on AC or DC. The 6 brushes probably indicate that it is a 6 pole motor to increase torque but at less speed.

(Car stater motors are often 4 pole. Most other brushed motors are two pole)

I don't quite understand:-
and I would have expected 3 brushes connected to one wire, 3 to another and that pair has continuity, while the other pair has no connection to the brushes.

You should wire the windings in series, with the reversing switch reversing just one of the windings.

Leaving the jumpers in place,
Line connects to 6
3 connects to one end of first pair
2 connects to other end of first pair
1 connects to neutral
4 and 5 connect to the other pair.

If the motor direction does not match the switch label, swap the wires on 4 and 5. Don't move the jumpers.

It might be worth testing it with no load on a 12V battery, with a 20 A fuse.

There is a danger of electric shock, getting fingers caught or massive overcurrent if things go wrong.

 

DIVER300 you are probably correct as to the position of the brushes in one pair of wires. So if this is the case, which pair would be in series first. I have tested for ohms between each pair and found one pair with about .4 ohms and the other with about .8 ohms.

Thank you for all the help.

 

I'll take that as a question. The answer is that it doesn't matter which comes first in a series circuit.

With low resistances like that, you may get a lot of current if things go wrong, so try starting with a car battery or with a big light bulb in series as well.

 

Wired up the motor as recomended by DIVER300 and it seems to be working fine. Thank you for all the help.