Motor Current Draw
Motor Current Draw
(OP)
Hi,
Is there a way (sure there is) to calculate the new current draw from an existing motor, if i increase the pulley size on a fan?
Thanks,
Is there a way (sure there is) to calculate the new current draw from an existing motor, if i increase the pulley size on a fan?
Thanks,





RE: Motor Current Draw
There is a big assumption that the system remains fixed (no flow control valves that will adjust themselves toward closed in response to the change), that the system flow characteristic is roughly DP~ flow squared. Also it assumes efficiency is constant. Finally I think this only holds when the dp is small relative to the total absolute pressure so the density is roughly constant.
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(2B)+(2B)' ?
RE: Motor Current Draw
Iken: If you're talking about a not-too-big fan, what I've done in the past to avoid overloading the motor is to purchase an adjustable-sheave type pulley, then increase the fan speeds by little bits while monitoring motor amps.
Of course, stop the fan and lock out the disconnect when adjusting...
Good on ya,
Goober Dave
RE: Motor Current Draw