old motor electric, rewire...stuck!

[plantlife]

Hi,

I've an old motor i'm going to rewire (for small lathe) but there was two strands of wire coming from the carbon brush motor area. No earth wire, old wires were not coloured....anyone got any ideas of how i can rewire this.
It is a 240v motor...thomson houston. No internet/googling results ;-(








thanks
andy

 

[rtbcomp]

I had a motor similar to that. It was a repulsion induction motor.

The brushes were in fact connected together and to nothing else, the rotor was a coil but in modern motors this is replaced by the aluminium/steel rotor.

From here

http://en.wikipedia.org/wiki/Commutator_%28electric%29#Repulsion_induction_motors

"These are single-phase AC-only motors with higher starting torque than could be obtained with split-phase starting windings, before high-capacitance (non-polar, relatively high-current electrolytic) starting capacitors became practical. They have a conventional wound stator as with any induction motor, but the wire-wound rotor is much like that with a conventional commutator. Brushes opposite each other are connected to each other (not to an external circuit), and transformer action induces currents into the rotor that develop torque by repulsion.

One variety, notable for having an adjustable speed, runs continuously with brushes in contact, while another uses repulsion only for high starting torque and in some cases lifts the brushes once the motor is running fast enough. In the latter case, all commutator segments are connected together as well, before the motor attains running speed.

Once at speed, the rotor windings become functionally equivalent to the squirrel-cage structure of a conventional induction motor, and the motor runs as such."

 

[plantlife]

I had a motor similar to that. It was a repulsion induction motor.

The brushes were in fact connected together and to nothing else, the rotor was a coil but in modern motors this is replaced by the aluminium/steel rotor.

From here

http://en.wikipedia.org/wiki/Commutator_%28electric%29#Repulsion_induction_motors

"These are single-phase AC-only motors with higher starting torque than could be obtained with split-phase starting windings, before high-capacitance (non-polar, relatively high-current electrolytic) starting capacitors became practical. They have a conventional wound stator as with any induction motor, but the wire-wound rotor is much like that with a conventional commutator. Brushes opposite each other are connected to each other (not to an external circuit), and transformer action induces currents into the rotor that develop torque by repulsion.

One variety, notable for having an adjustable speed, runs continuously with brushes in contact, while another uses repulsion only for high starting torque and in some cases lifts the brushes once the motor is running fast enough. In the latter case, all commutator segments are connected together as well, before the motor attains running speed.

Once at speed, the rotor windings become functionally equivalent to the squirrel-cage structure of a conventional induction motor, and the motor runs as such."

Hi,

Thank you for the info, its good to read about how it works. ;-)

atb

 

[rtbcomp]

I'm not saying yours is the same, just that it might be.

A bit of background here

http://www.gracesguide.co.uk/Thomson-Houston_Co

 

[rtbcomp]

There's a picture of mine here

http://www.mig-welding.co.uk/forum/showthread.php?t=8692

 

[plantlife]

I'm not saying yours is the same, just that it might be.

A bit of background here

http://www.gracesguide.co.uk/Thomson-Houston_Co

thanks for that, only info i could find was on Wikipedia and that was limited.

There's a picture of mine here

http://www.mig-welding.co.uk/forum/showthread.php?t=8692

That looks a canny size.