Emco Mentor Mill conversion

[Ross77]

sorry for the short reply, had to go out sooner than I thought. thanks for getting star - delta spec I was hoping to get the wire colours for each coil but the best I can find from emco is brown, blue, black, to the motor. looks like I'm going to have to find them buy trial and error, or testing. as a starting point Ill draw up the existing arrangement and get back back to you if that's ok?

Thanks again for your help. if there is a way to get this working on 240v then I'm keen to sort it out so I can test the machine before I make to many plans.........looks like some gorilla has been pounding on the draw bar with a hammer to release the collet holder and bent the top part of the spindle. arrgg

[GEOFFREY]

Stick with it it Ross. I am fairly sure you will be able to run that motor on single phase with with your inverter (or capacitors!).
When you check out the wiring you should be able to find the star point fairly easily, and once the wires are separated can then just do a simple ohms check to identify the three windings. Reconfigure as delta and you will be away. Good luck. G.

[m_c]

I'd highly doubt the coil wiring will have any sort of identification. They're usually just the enammeled copper wiring with a bit extra insulation slid over the top.

[Ross77]

I think I have it sorted now! the motor was wired in star and has 6 coils which are interconnected in pairs. Before I cut the star connection I tested the input wires and got 100 ohms across each phase, which in star con fig is 2 coils (4 actually). When I cut the star connection and retested each coil I got continuity from the buzzer and 50 ohms reading.

The question is can I run it using a capacitor in delta configuration to test? or will it only run from the inverter and risk damaging that if I got the rewire wrong? Lastly can I use a cap from another 240v motor or is the capacitance value dependant on the motor?

Thanks again

[Swarfing]

Thing is you will need a few caps and they will be different sizes for the phases. By the time you have messed around you might as well get an inverter (vfd). If the motor does not work out i would still use another 3 phase motor.

[Ross77]

Ah. I thought is was 1 cap in one of the phases or is that for star config?

I was only wanting to try the cap route for initial testing after I rewired the motor as I don't want to damage the VFD. (already got one)

Is there any other way to test a 3 phase motor?

[irving2008]

Ah. I thought is was 1 cap in one of the phases or is that for star config?

I was only wanting to try the cap route for initial testing after I rewired the motor as I don't want to damage the VFD. (already got one)

Is there any other way to test a 3 phase motor?

you wont damage the VFD*. if its a half decent one it'll have foldback current limiting and overheat protection.

*but dont blame me if you let out magic smoke