Help choosing a small 3 phase motor
Help choosing a small 3 phase motor
(OP)
Hello Again !
I need to purchase a motor for a machine I'm building about 750w 1400rpm and I'm not sure whether to go for a single phase 240v or 3 phase. I don't have 3 phase supply so if i went that route then I'd be getting into a controller which I may need anyway for speed control.I'll be adding pulleys to slow the driven shaft to 500rpm.I will probably need the ability to switch direction of rotation so don't want to get the wrong motor that can't easily be switched.Not sure about the start capacitor and run capacitor options pro's and con's. Under £100 seems to be the going rate for this size
Any help appreciated
Thanks
I need to purchase a motor for a machine I'm building about 750w 1400rpm and I'm not sure whether to go for a single phase 240v or 3 phase. I don't have 3 phase supply so if i went that route then I'd be getting into a controller which I may need anyway for speed control.I'll be adding pulleys to slow the driven shaft to 500rpm.I will probably need the ability to switch direction of rotation so don't want to get the wrong motor that can't easily be switched.Not sure about the start capacitor and run capacitor options pro's and con's. Under £100 seems to be the going rate for this size
Any help appreciated
Thanks





RE: Help choosing a small 3 phase motor
http://www.orientalmotor.com/products/ac-motors/ac...
I'd recommend a 3ph motor over a 1ph motor. You won't get good speed control from a 1ph motor. A VFD of the size necessary to run your motor can be powered from a single phase source, even a wall outlet.
Gearing/belting down the motor to get close to your necessary output speed is a good idea. You get more speed range, and you increase your available torque as well. I usually shoot for my output speed to be approximately 80% of motor base speed. That way, I have some headroom if I need to increase speed later, without exceeding the motor base speed.
SceneryDriver
RE: Help choosing a small 3 phase motor
Thanks
RE: Help choosing a small 3 phase motor
RE: Help choosing a small 3 phase motor
For you, you will have a contact closure input on the VFD that tells it to Run in Fwd, then another one you set up to tell it to Run in Rev and if they are both Low, it stops. Or you can have one that tells it to just Run and Stop, then another one that when you command it, tells it Fwd or Rev based on it being High or Low (On or Off). Your choice.
If variable speed is of value to you, I would not consider doing this any other way.
"Will work for (the memory of) salami"
RE: Help choosing a small 3 phase motor
RE: Help choosing a small 3 phase motor
RE: Help choosing a small 3 phase motor
RE: Help choosing a small 3 phase motor
If you buy single phase VSD to run your motor, you need to connect the motor up in the delta connection.
I have a very nice spread sheet where you put your values and it produces a graph of the results and red
Lines danger operating areas. If you want this you will need to tell me how to get it to you.
Above 100 Hz you may need to look at your bearings as well as forced cooling.
RE: Help choosing a small 3 phase motor
"Will work for (the memory of) salami"
RE: Help choosing a small 3 phase motor
Can you suggest a decent one as prices vary a lot how about this one
Link
£160 "Engineers mate" they sell motors too
Thanks