How to rewire from a three phase motor to a 240 volt single phase motor.

I am replacing a  40 year old three phase motor with a 240 volt single phase motor. The three wires are all black and not coded in any way. How do I measure with a voltmeter? I assume one wire is neutral, but which one? Thanks.

If its three phase and presented on three wires, there isn't a neutral, as Re-Design says. In fact there are 415 volts between each of those wires. If you HAVE a three phase supply, there really isn't a better way of driving a motor than using it.
Re-design8 years ago
Doesn't have a neutral.<br /> <br /> Check <a href="http://www.3phasepower.org/">this link down at the bottom of the page</a> "single phase equipment on three phase source". Or something like that.<br /> <br /> I guess this is the place a prudent person might suggest that this is a project that might be better suited to a licensed electrician rather than a figure it out while I go along DIY'er. Especially since there are ways to get more than 220 out of some 3 phase systems.<br /> <br /> Either way - best of luck to you.<br />