709-VmA Series

Electronic Fan Speed Control

The 709-VmA Series electronic Controller is designed to provide proportional speed control of single phase motors for variable air volume applications. The Controller may be used with shaded pole or permanent split capacitor type motors from 120V to 480VAC.

The Controller phase proportions (modulates) the single phase power to regulate RPM as determined by a 2-10V DC or 4-20mA DC input signal provided by the customer. The optional 266 PI Interface can also be used to provide a desired set point of operation and drive the control as needed.

The 709-VmA Series Controller provides independent maximum and minimum speed limit adjustments. Also included, a separate continuous minimum speed or “drop out” function at minimum input.
Stacks Image 400
Applications
The variable speed Controller is used for adjustment of motor RPM within a limited range of operating temperatures that assure adequate ventilation of the motor. The Controller is designed for air moving applications using squirrel cage or propeller type fans. As an example, to maintain a set flow of air through a duct, use the 203-5 Flow Transducer and the 266-PI Interface.

This control may be suitable for other, non air-moving, direct drive motor applications. Motors should be open, drip-proof types.
Applicable Motors
  • Permanent split capacitor (PSC) or shaded pole motors
  • 115 to 480 Volts AC (models 709D-xVmA)
  • 115 to 240 Volts AC (models 709E-xVmA)
  • max 5 Amps (models 709x-VmA)
  • max 10 Amps (models 709x-BVmA)
  • max 18 Amps (models 709x-CVmA)
Features
  • Multi-voltage applications
  • Motor speed proportional to the 2-10 V DC or the 4-20 mA DC input signal
  • Minimum and maximum speed adjustments
  • Motor cut-out adjustment
Data Sheets and Instructions
“Dallas