Johnson Controls VA-9070 Series Technical Bulletin

Introduction
VA-9070 Series quarter-turn, electric rotary actuators with manual override can be used on most
Johnson Controls® VF Series Butterfly Valves sized for up to 18,000 lb·in (2034 N·m) of torque.
VA-9070 Series electric actuators cannot be used on the VF4000 Series and VF5000 Series Butterfly
Valves. Operating speeds vary between six and sixty seconds.
Internal and External Components
The VA-9070 Series actuator is divided into two internal sections: the power center below the switch
plate and the control center above the switch plate. The power center contains the capacitor and
gear motor, with its spur gear train. The power center drives a final non-backdriveable worm gear
output. The power center also houses an override mechanism for manual operation. The control
center has several user-accessible components: the camshaft assembly, limit switches, terminal
strips, torque switches, heater, and servo.
On the outside of the actuator housing are adjustable mechanical travel stops, a large position
indicator, the manual override handwheel, and dual conduit entry ports. The external coating is a
polyester powder coat, providing resistance to Ultraviolet (UV) radiation exposure and chemical
exposure.
Electrical Operation
The 120V motor in the VA-9070 Series actuator is a permanent induction split capacitor design
(single phase AC power). The 24VAC motor in the VA-9070 Series actuator is a permanent magnet-
brush D.C. motor. Travel limit switches are mechanical Form C Single-Pole, Double-Throw (SPDT)
switches with two independent circuits. These SPDT switches are rated at 10 amperes (75 to 80%
power factor), 1/3 hp 120 VAC and 1/2 hp 220 VAC.
If the torque capacity of the actuator is exceeded to the point where the motor stalls and overheats,
a thermal protector switch built into the motor windings automatically disconnects the motor
power. Once the motor cools sufficiently, the thermal switch resets.
Mechanical Operation
Mechanically, the ratio of the gear motor determines the speed of the actuator. The gear motor
uses high-efficiency spur gears with different ratios for the different speeds. Initial gear reduction
through the spur gears transfers to the worm shaft.
The final gear reduction and output happens through a non-backdriveable worm gear set. An
indicator-camshaft linked to the output shaft determines positioning. The manual override drives
the worm shaft when engaged.
Manual Override Operation
The manual override operates similarly to the adjusting knob on a mechanical wristwatch. To
engage the manual override, pull the handwheel to its outermost position. When the manual
override engages, the actuator stops electrical operation.
A yellow position indicator shows that the manual override is engaged. Dry contacts on an internal
switch can provide remote electrical indication of the override status.
Spring plungers hold the two handwheel positions (engaged and disengaged) in place. The
handwheel remains in position until physically moved. Rotating the handwheel in a clockwise
977325
2023-04-12
VA-9070 Series Electric Rotary Actuators
for Two-Position and Modulating Service
Technical Bulletin
VA-9070