Allen Baker (Customer) asked a question.
Currently have a Ziehl-Abegg single speed motor, 1Hp, 115V, 60hz, 1040/min, fan motor.
Is it possible to control the rpm value to an accuracy of single rpms using motor controllers such as the DURApulse GS21-22P0? If so how would I configure this?
Is it possible to control the rpm value to an accuracy of single rpms using motor controllers such as the DURApulse GS21-22P0? If so how would I configure this?
I have very little knowledge in this area and yet I have been tasked with finding a way to control a fans speed to single rpms.
All AC drives at Automation Direct (such as the GS21-22P0) can only control 3 phase 230V or 460V motors. The motor specification of 115V you listed would not be compatible.
At 115V that is almost certainly a single phase motor, that puts significant restrictions on what speed control is practical. "rpm value to an accuracy of single rpms" is likely not possible with a single phase motor. Also a GS21-22P0 will not run a single phase motor. Likely the most practical option would be to replace the motor with a 3 phase one and use something like a GS21-22P0.
However I'm not clear on what you mean by "rpm value to an accuracy of single rpms" do you mean, for example; for 500rpm, not 499 or 501 but 500 exactly? or like 1 to 9 rpm? If either of those is literally true, I'd seriously consider a servo motor, a VFD with encoder feed back may be able to do it as well, but a servo would be more certain..
Oh, I just Googled " Ziehl-Abegg " and it looks like changing the motor may not be simple, the motor typically seems to be an integral part of mounting the fan blades. So I guess it come down to what does "rpm value to an accuracy of single rpms" really mean? some speed control of fan motors is often possible and easy if high accuracy is not needed but high accuracy is a lot harder.
@Tinker (Customer) To be more specific, I have to find a way to change the value by 1 rpm. Such as being able to change the value from 500 to 501, or 999 to 1000, or 423 to 424, etc..
There's no requirements on what controller is used just the ability to preform the task.
I just re-read the question, looks like the question is; can the existing motor be controlled "to an accuracy of single rpms", for that question the answer is easy: No.
That is probably a permanent split capacitor motor and some speed control is certainly possible, but that kind of precision is almost certainly going to require closed loop control and there is no reason I can think of for that to be commercially available since that type of motor is not really suitable for that use.
Now controlling the speed of the fan could be possible if the motor was changed (but it doesn't look like that would be easy or practical for many of Ziehl-Abegg products) but that might not have actually been the question.
Since this is an air moving application I wonder if you are being asked to "find a bucket of prop wash"?
Though I've dealt with enough sales people who would promise something like that to the client and leave it to someone else to figure out how to do it. Thinking back, by comparison it sounds pretty easy to machine a new mount to install a servo motor in the fan, and cheap too!