Wiring a 12 lead 10hp Yaskawa motor to VFD - need help

Hello,

I bought a 10 hp Okuma LS lathe and a VFD to go with it. After looking at the wiring diagram that came with the machine I'm confused!

The motor is a Yaskawa 3 phase induction motor type BOF, 7.5 kW, 4 poles, Ins A, rotor K2, 220/440 volt code G.

The thing that's confusing is that the machine has 4 contactors for the motor. One for forward rotation, one for reverse, one for delta, and one for wye. I've never seen one wired like this but I haven't been around very many industrial motors. The machine does have a soft start based on the start handle position. I'm guessing the delta and wye have something to do with this but I'm not sure. Any thoughts?

Sorry if this has been answered before. I've searched but can't find anything.

Thanks,
Jason

Jason,

Wye-delta is a common way to start a larger motor...especially favored in Europe. This starts the motor gradually and reduces current draw and subsequent power costs.

Your VFD will be connected directly to the motor without using any of the mags. The drive has the ability to softly accelerate is you desire it. Connect the 12 motor leads for whatever voltage you are using. There should be a connection diagram on the inside cover of the junction box.

You will end up with three combined leads that will get connected directly to the output of your frequency drive. If you need to, Google 'three phase motor connections' and you'll find a schematic for a 12 lead motor...it's easy to do.

Stuart

Stuart,

Thank you very much! I was hoping it wouldn't be a problem.

Jason