TB Woods SW1

[prifral]

I have a TB Woods SW1 model SW1C1S015H02 hooked up to a 2hp 220v 3ph motor.

The reason for this combination is that I only have a 120v power available to run a 2hp 3 phase mill. The VFD is only rated to 1.5hp, 1.1kW and the motor is 2hp, 1.5kW. I was told that this would be ok so long as I didnt mind the loss in motor hp.

So far everything is hooked up as I could surmise to be correct. The VFD powers on and I am able to power up and control the motor. But something is definitely not right. W/some VFD adjustments, the motor is only able to reach a max of 40Hz if the Acceleration Ramp Time is set to a slow 60 seconds. The VFD trips if acceleration is set faster or if pushed past 40Hz. The VFD will also trip if ran more than about a minute(at any speed) due to an "over-current on drive output" or "motor thermal overload". Also the motor spindle seems to slow down at around 10Hz then speed up again past that. Randomly, the motor will self reverse direction at around 3Hz.

Needless to say - though the wires are hooked up - its definitely not right. I have moved the 3 motor wires to every combination to U,V,W to no avail. Below is my current wiring. Any help would be greatly appreciated.

[duak]

Hello,

My background is in electrical engineering and designed motor drives many years ago. I'm not familiar with the TB Wood's drive nor with the motor you are using but I think it can be made to work.

I was doing some experiments this last summer using a KEB 230 Volt 1 HP drive with a 2 HP motor that I'd like to use on my home drill press. The 2 HP motor is physically larger than the 1 HP it had originally and so it should be able to handle lower speed lugging better. I strapped the motor for 460 V which makes the motor appear to be 1 HP at 230 V. I then programmed the drive to give full (230 V) voltage for 30 Hz rather than 60 Hz. The combination will easily go above 30 Hz but will be limited in torque and power because it is underfluxed ie., voltage is too low for Hz or RPM.

Your motor appears to be a two speed type. I don't have any experience with this type nor can I predict how it may interact with the drive. According to page 12 of this link: http://www.ibiblio.org/kuphaldt/socr...ut/acmotor.pdf typically motor terminals 1, 2 & 3 are connected together and drive is applied to terminals 4, 5 & 6. Unless the motor label forbids this connection, you might want to give it a try.

The motor needs more power ie., more current than the drive can supply at an arbitrary frequency. It doesn't appear that you can change the motor voltage by strapping as I did. I don't have the TB Wood's drive manual, but you should be able to change the V/Hz function. I would try programming the drive to deliver full voltage at 83 Hz or higher. (60 Hz * 2 Hp/ 1.5 Hp).

If you can get a link to the manual to me I can take a look-see for a way to get you going. BTW, I also got a 3 Hp motor running with the 1 Hp drive but decided not to because of mounting problems.

Cheers,

Duane

[prifral]

Duane,

I took a chance and went to a motor surplus center and got a 1.5hp 3 phase motor for cheap($30). Wired it up and and it worked right away. As you may have guessed my previous 2hp motor was way too big for the drive I'm using. So my issue is resolved and my mill is up and running. Thanks for your reply.