VFD versus Soft Start
VFD versus Soft Start
(OP)
I am new to the water industry. Would like to know more about the differences between VFD and soft start. Terms that are frequenly used in the industry. Trying to get a layman's perspective on this.





RE: VFD versus Soft Start
Consider soft start to save on starting current draws when you start up large electrical equipment.
Consider VFD/VSD ONLY when you have variable flow requirements that can range from 50%-90% of BEP flow (70 to 90% best range) and the pump still produces enough head to move water in your pipe system, as opposed to a soft starter with a constant speed pump.
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RE: VFD versus Soft Start
Softstart runs a motor at one constant speed; however, it ramps the speed up/down slowly during start/stop to save electrical costs.
VFD can operate the motor over a wide range of speeds as well as ramping the speed up/down during start and stop. This allows a pump to more accurately match the demand as well as save electrical costs.
RE: VFD versus Soft Start
A variable-frequency drive (VFD) is a system for controlling the rotational speed of an alternating current (AC) electric motor by controlling the frequency of the electrical power supplied to the motor. A variable frequency drive is a specific type of adjustable-speed drive.
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