Providing Solutions in centrifugal
Speed Switching for Over 65 years
Motor Switch Selector
Basic Operation

Capacitor start/capacitor run motors provide continuous voltage sensing information which can be used to extract speed data from the voltage across the motor start winding. By comparing this start winding RPM-sensitive voltage to the main AC input voltage (which serves as a reference voltage), the switch determines when the start circuit should be de-energized. The electronic switch interrupts the start circuit current after the motor has accelerated to the cut out voltage (speed), and reconnects the start circuit whenever the speed sensitive circuit senses the motor voltage (speed) has decreased to a preselected cut in voltage (RPM) level.

Capacitor start/capacitor run motors exhibit current transients and higher voltages across the start switch. These electrical stresses occur due to the switching of the two capacitors (start and run) that are connected in parallel during motor start and may have different voltages at time of restart. These stresses occur at restart with both mechanical and electronic start switches. The VR switch features circuitry designed to eliminate the effects of these conditions.
Unit of Measure


Typical Maximum Motor

N/A 1/2 hp

Full Load Motor
Current Rating (115 Volts)

N/A 8 A

Full Load Motor
Current Rating (115/230 Volts)

N/A 8/4 A

Switch Rating Permissible Max Start Capacitor Current

N/A 16 A

Start Circuit Voltage

N/A 115 V

Part Number

N/A 4-7.71016-12-UB1 4-7-71016-12-UA1 4-7-71016-19-UA1 4-7-71016-19-UB1

Typical Cut Out Voltage

N/A 130 V147 V

Typical Cut In Voltage

N/A 30 V37 V

Package Style

N/A 12 19

Additional Features


  • Capacitor Shape: Allows for easy mounting under a motor doghouse (19 package style).
  • Environmentally Protected: Immune to moisture, dust, dirt, shock and vibration.
  • UL E71115 and Canadian UL Recognition.
  • Completely Solid-State with No Moving Parts: SINPAC® Switches have no physical constraints to affect their operation. No wearing parts mean high cycling, no arcing contact, Low warranty.
  • Silent Operation: No switch noise.
  • Operating Temperature: -40 ºC to 65 ºC (-40 ºF to 149ºF) [for operation between 65 ºC and 85 ºC (149 ºF and 185 ºF). consult factory]
  • Operating Voltage: 115 VAC SINPAC® Switch 90-130 VAC. For dual voltage motor equipped with center-tapped mam winding: 90-130 VAC or 180-265 VAC.