E500 Low Speed torque

[sid]

I am working on machine where it requires full load torque at speeds 1HZ or below. I am planning to purchase E540 Drive (2Hp) for operation in Vector mode. Is it possible using E500 drive to get full load torque at speeds as low as 1HZ. Machine is required to work at constant speed anywhere between 1Hz to 50Hz.

[Colin Carpenter]

Even if you could get full torque at that low a speed (and I don't know the answer), how would the motor stay cool with a cooling fan going that slow. Reckon you'd have to rig up a compressed air nozzle to stand a chance of keeping it cool. Wouldn't some form of variable speed gearbox be a better idea?

[TimWilborne]

Yes I was kind of baffled by the low Hz output. Drive should be fine but I don't think a motor could handle it continuously with a cooling fan. What would the duty cycle be? I have seen this one other time will a compound gearbox, that is not a technical term. Pretty much the small (slow) motor ran through one gearbox, then the output shaft of that gearbox was connected to the input shaft of another gearbox along with a sprocket to a larger motor. The small motor ran the low speeds while also turning the larger motor. Then when it was time to go faster than the smaller motor would go the larger motor would start and the smaller motor would stop. I would say it was a bit rough on the smaller motors bearings and the larger motor would have to be oversized enough to back drive the small gearbox but think it would be better than running 1hz for a long duration

[waynes]

Hi guys, I remember using a Danfoss drive (VLT5000 range) and a SyncPos card. The setup for something like this application is perfect. You do need an encoder mounted on the back of the motor though. I remember that we were able to get 100% torque at 0Hz. So, if you try and turn it with your hand,it would simply energise the motor to withstand any movement. Oh yes, you need to add a forced cool fan on the back of the motor. This is the only way to ensure that the motor has constant air flow over the cooling blades. Anyway, I do not know if the Mits drives have something like this. I will have a look.

[sid]

Motor is provided with forced cooling. Machine is having feed rolls driven by motor(2Hp) which pulls the wire and forces wire against obstacle to form wire in form of spring. Since wire is forced against obstacle, drive is required to run in costant torque even at low speeds.Drawing.pdf Edited November 7, 2006 by sid

[TimWilborne]

What is the time duration it would have to run at these low speeds? How long would it have to rest?

[sid]

During starting, speed of 1HZ is required for few minitues for product adjustment then after confirmation, speed is between 5Hz to 50Hz depending upon output production and accuracy requirement.

[FNMdeJong]

Yes you can get a high torque (150%) at low speeds as 1 HZ, with the general purpose flux-vector control. Be aware that this overload is limited to 60 sec. When only 100% load is generated, then there is no limitation in time. Just see the standard specifications in the manual or sales brochure of the FRE series.

[panic mode]

what is max speed required and what is nominal speed of the motor?

[sid]

Rated speed of motor is 1500rpm(50Hz) and max speed required is also 1500rpm(50Hz). Min speed required to be 150rpm(5Hz)