Motor Wiring Question

Hello!

We have an older Hobart mixer/chopper which has a shroud around the motor with the nameplate data affixed to it. On the nameplate, it indicates 230V 3phase, 1750/3500 RPM. With this in mind, we were thinking it was a dual speed motor depending on how it was wired.

Upon further investigation, by taking the motor shroud off, we noticed a sticker on the actual motor which shows high and low voltage wiring diagrams. This being the case, we are assuming the motor is not dual speed as stamped on the motor shroud. We are assuming the motor is not original and the original two speed motor was replaced with a single speed dual voltage motor.

My question is: Could this dual voltage motor really also be dual speed? The motor is wired as followes:

Line goes to 1, 2, 3
6-9 are tied together
8-5 are tied together
4-7 are tied together

Putting a tach on the motor indicates it is turning at 1750 RPM. I'd really like to get to 3600 RPM, but I'm not sure this motor is able to be wired for that.

TIA,

Greg

You are correct that the motor was replaced with a single speed/dual voltage motor at some time in the past. To get dual speed back, you will need to get a dual speed motor.

I've seen duel voltage dual speed motors. Does it mention anything about wye (or star) delta (on the name plate)? Is it controlled by one contactor or by three?

Or just switch to a two pole motor at the voltage you need. Be sure you know how much hp you need at the higher speed.

It's possible to have a motor that's both Dual Voltage and Dual Speed. With that being said I don't know of any off the shelf because there would not be much of a market / demand for them.

What you have is most likely a motor custom made for that Equipment OEM to add flexibility to their machine and a better fit for a wider range of customers.

The downside to OEM custom parts like this is you have to go back through the OEM to source spares as they are not available by other means.

Greg Dake said:

Hello!

We have an older Hobart mixer/chopper which has a shroud around the motor with the nameplate data affixed to it. On the nameplate, it indicates 230V 3phase, 1750/3500 RPM. With this in mind, we were thinking it was a dual speed motor depending on how it was wired.

We are assuming the motor is not original and the original two speed motor was replaced with a single speed dual voltage motor.

My question is: Could this dual voltage motor really also be dual speed? The motor is wired as followes:

Line goes to 1, 2, 3
6-9 are tied together
8-5 are tied together
4-7 are tied together

Putting a tach on the motor indicates it is turning at 1750 RPM. I'd really like to get to 3600 RPM, but I'm not sure this motor is able to be wired for that.

TIA,

Greg

Click to expand...

Greg,

You have not mentioned your operating voltage. If it is 480 this would be a classic situation to add a a vfd. It appears that the mixer can handle a 3600 rpm input. The trick when using a vfd to overspeed a small motor when your supply is 480 is to reconnect the motor leads for 240 volt and purchase a 480 volt VFD sized at twice your motor full load amps @480 volts. Then reprogram the vfd to deliver 240 volts @ 60 hz and 480 volts @ 120 hz. You will have all the torque that the motor has in it's present configuration and it will not lose any torque above 60 Hz.