P
Hello list members.
I'm considering the replacement of the 4 motors in an industrial washing machine with a single motor/VFD combination. What concerns me is the wide speed range that the motor/VFD would need to handle, since it has to replace the current 15 hp motor at low speeds (about 30 rpm) and the current 20 hp motor at high speed (about 500 rpm). Thats a speed ratio of about 17:1 between the highest and lowest speeds. Right now the switching between motors is done through a series
of pneumatic clutches and speed reducers.
The low speed is needed for the normal washing cycle (reversing direction periodically) for about 40 minutes, and the high speed is required for the 10 minute spinning cycle. Does anybody has any comments on this wide range of speeds at this power levels? I have worked with wide speed ranges on VFDs with no problems, but maybe motor heating would be an issue at low speeds in these particular application, since it would have stay at about 6% maximum speed most of the time, and still be able to go to 100% speed for
approximately 10 minutes each cycle.
Thanks and best regards, Pat.
I'm considering the replacement of the 4 motors in an industrial washing machine with a single motor/VFD combination. What concerns me is the wide speed range that the motor/VFD would need to handle, since it has to replace the current 15 hp motor at low speeds (about 30 rpm) and the current 20 hp motor at high speed (about 500 rpm). Thats a speed ratio of about 17:1 between the highest and lowest speeds. Right now the switching between motors is done through a series
of pneumatic clutches and speed reducers.
The low speed is needed for the normal washing cycle (reversing direction periodically) for about 40 minutes, and the high speed is required for the 10 minute spinning cycle. Does anybody has any comments on this wide range of speeds at this power levels? I have worked with wide speed ranges on VFDs with no problems, but maybe motor heating would be an issue at low speeds in these particular application, since it would have stay at about 6% maximum speed most of the time, and still be able to go to 100% speed for
approximately 10 minutes each cycle.
Thanks and best regards, Pat.