zbang
Senior Member
- Location
- Roughly 5346 miles from Earls Court
I'm back to looking at the surface grinder posted about in https://forums.mikeholt.com/threads/vfd-for-reversing-a-grinder.2567411/.
Current thought is to downsize the motor from 1.5 HP to maybe 3/4 or 1/2 HP (lower torque & rotating mass, doesn't need the power anyway), remove the existing reversing contactors, and pop in a VFD for a ramped-up acceleration and reversing (0.5 sec accel, coast decel?, it'll alternate between fwd and rev without a stop between).
The machine's owner asked whether we should actively brake the load with a braking resistor. Is this rational? I don't see any small 230v VFDs that use them; our go-to for small motors is the Teco L510 series, but the 230v models don't support a BR. I'm also not sure how much the VFD will like being slam-reversed every second or faster.
The machine hasn't seen much use in the last year or so, but some upcoming projects may call for it.
Current thought is to downsize the motor from 1.5 HP to maybe 3/4 or 1/2 HP (lower torque & rotating mass, doesn't need the power anyway), remove the existing reversing contactors, and pop in a VFD for a ramped-up acceleration and reversing (0.5 sec accel, coast decel?, it'll alternate between fwd and rev without a stop between).
The machine's owner asked whether we should actively brake the load with a braking resistor. Is this rational? I don't see any small 230v VFDs that use them; our go-to for small motors is the Teco L510 series, but the 230v models don't support a BR. I'm also not sure how much the VFD will like being slam-reversed every second or faster.
The machine hasn't seen much use in the last year or so, but some upcoming projects may call for it.