VSDP-Series (Variable Speed Pump Drive Panel)

VSD Sizing & Selection

Sizing VSDP Control Panels

• Size the VSDP based on the maximum current requirements.
• Do not size the VSDP based on horsepower rating.
• Horsepower rating is based on standard NEMA B 4-pole motor design as represented in NEC table 430.250 full-load current, three-phase alternating current motors.
• Verify motor FLA for proper drive sizing and select drive with full load amps equal or greater than the motor FLA for pumping systems not continually operating in the motor service factor.
• For pumps operating in the service factor will require the VSD full load output amps to equal or exceed the motor service factor or maximum amp rating (ie., 1.15 x FLA = Required Drive FLA). Selecting the next larger size VSD might be required.
• When sizing for submersible motors size the VSD based on the service factor or maximum amp rating of the motor as provided by the submersible motor manufacturer. Selecting the next larger VSD might be required.
• Refer to table VSDP-1 located below for output amp requirements for different pump type and if the pump is continually operating in the motor’s service factor.
• Altitude limits: No derating is necessary below every 3,000 feet above sea level. Derate the drive output rating by 1% for every 300 feet of increase in elevation above 3000 feet.

Table VSDP-1