AC Motor Ramping Startup
AC Motor Ramping Startup
(OP)
I am using an AC motor in my project. I would like the motor to ramp from stop to full speed (1700rpm) over several seconds when you turn it on. Currently it goes from stop to full speed as soon as you turn the power on. Is there a simple circuit or other way to ramp the speed of an AC motor? If this was a DC system then I could use a simple RC first order circuit to ramp the input voltage. Is there a way to make this work with an AC system?
Thanks for your time,
Jason Leonard
Thanks for your time,
Jason Leonard





RE: AC Motor Ramping Startup
RE: AC Motor Ramping Startup
"Venditori de oleum-vipera non vigere excordis populi"
RE: AC Motor Ramping Startup
http://www.bodine-electric.com/Asp/ProductSeries.asp?Context=5&Name=42R%20Series%20AC%20Induction%20Motor
The more that I learn about starting these things, the more I think that I should just get an AC controller. Bodine has what looks like a pretty nice one for $200. Then not only would I be able to ramp up the starting speed, but I could set the speed to whatever I wanted.
RE: AC Motor Ramping Startup
You could however consider using the 0273 version of that motor, which is 230V 3 phase, and then use the inverter which will create 3 phase from your 115V 1 phase source. That motor appears to use the same housing and frame, it is 1/4HP instead of 1/6HP. But with a VFD, the extra power should not be a mechanical risk becasue you are soft starting and those VFDs have current limit.
My one comment on using these small motors from Bodine (from my personal experience) is that they have a tendancy to overheat when running at low speeds from a VFD because their fan cooling is apparently inefficient below 1/2 speed. But if you don't plan to run slower than that, no problem, they are a good quality motor.
"Venditori de oleum-vipera non vigere excordis populi"
RE: AC Motor Ramping Startup
On jraef’s 3ø-motor suggestion, if your could accommodate a 230V 1ø input, Bodine lists a ‘closeout-priced’ VF drive for $89. www.bodi