Phase 3 wiring colours?

[Noods]

Hi All

purchased an old cincinatti ( USA built) workshop phase 3 pillar drill.. Needed tlc.. Unfortunatly the previous owners had removed the connection plug.. Drill delivered to me unseen..

In the junction box I have 3 red wires going into 3 blacks and one green wire into a green and yellow..

At at the plug end I have 3 blacks and the green and yellow..

As as a car tech I'm a bit confused..

Many thanks..

 

[Marvo]

It looks like a 3-phase machine without a neutral but you should find the info plate and confirm this first before connecting. Was the machine already running in the UK before you bought it? If it was purchased from the US the voltages and supply frequency won't be compatible with your supply.

The green/green-yellow will be the earth, the 3 blacks/reds will be the 3 phases. This thing is probably rotation critical so if you connect it up and it runs in reverse you'll need to swap over any two of the 3 phase connections.

Please bear in mind you're dealing with a 400v supply so if you're unsure how to prove the circuit is isolated or you're not comfortable with your abilities rather get a sparky to assist you.