Johnson Controls VA-9070 Series Service manual

VA-9070 Series Electric Rotary Actuators
for Two-Position and Modulating Service
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
VA-9070
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direction rotates the output shaft in the same clockwise (closed) direction. Rotating the handwheel
in a counterclockwise direction rotates the output shaft in the same counterclockwise (open)
direction.
Pre-installation Storage
A temporary conduit entry plug, installed in shipped actuators, prevents foreign matter from
entering the actuator. Store the actuator properly in a dry, temperature-controlled area to
prevent moisture from entering through this temporary plug. Replace the temporary conduit
plug with a permanent conduit plug if the actuator is stored for a long period of time or stored in
adverse conditions. Prevent condensation from forming by maintaining a near constant external
temperature and supplying power to the heater internal to the actuator.
Installation
Mounting
VA-9070 Series electric actuators are suitable for direct mounting on Johnson Controls VF Series
Butterfly Valves. VA-9070 Series Electric Actuators cannot be used on the VF4000 and VF5000 Series
Butterfly Valves. Installing the VA-9070 Series actuator onto other quarter-turn valves or devices
requires proper mounting hardware.
When mounting the actuator in the standard position, orient the actuator with its handwheel in a
vertical plane and parallel to the pipeline. When mounting the actuator on a vertical pipe, position
the actuator with the conduit entries on the bottom to prevent condensation from entering the
actuator by way of the conduit. In all cases, position the conduit to prevent drainage into the
actuator.
Mount the actuator to the valve using the following procedure:
1. Manually operate the actuator until the output shaft of the actuator lines up with the valve
stem. If possible, use an intermediate position, such as valve disc/stem and actuator half-open.
2. Place the proper sleeve adaptor (if required) onto the valve stem. Apply a small amount of
grease to the sleeve adaptor to ease assembly.
3. Install the furnished mounting studs by threading them all the way into the actuator base.
Insert the short, threaded length into the actuator.
4. Mount the actuator onto the valve stem. Be sure the mounting studs are properly aligned with
the holes in the top plate of the valve or the mounting bracket. If necessary, manually override
the actuator to align the mounting studs with the mounting holes.
5. Lower the actuator onto the valve and secure it tightly in place with the furnished hex nuts and
lock washers.
Wiring
1. Connect the actuator to field wiring
2. Terminate all field wiring at the actuator terminal strip in accordance with the wiring
diagrams attached to the inside of the actuator cover.
Note: The terminal strip accepts wire sizes ranging from 10 to 22 AWG(12 to 22 AWG for
the servo). Do not use wire smaller than 18 AWG.
Note: The motor full load current is noted on the nameplate of the actuator.
Note: The heaters use approximately 0.5 amperes at 110 volts.
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3. Properly seal the conduit connections to maintain the weatherproofed integrity of the
actuator enclosure.
Note: The square-head conduit plug is weatherproofed but may eventually degrade. If
the square-head conduit plug degrades, replace it with a metal plug.
Wiring Diagrams
Shown below are the typical wiring diagrams for their respective applications
Figure 1: 120V on/off actuators
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Figure 2: 120 V proportional actuators
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Figure 3: 24V on/off actuators
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Figure 4: 24V proportional actuators
Multiple Actuator (Parallel) Wiring
Use a multiple pole switch to connect two VA-9070 Series electric actuators. See the Correct wiring
schematic in Figure 5.
Do not connect more than one actuator to a Single-Pole, Double-Throw (SPDT) switch. In the
actuator, voltage is present on the non-powered motor winding (opposite to the powered motor
winding). Connecting the voltage-containing, non-powered motor winding to another voltage-
containing, non-powered motor winding interferes with the motor performance. See the Incorrect
wiring schematic in Figure 5.
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Figure 5: Correct and incorrect wiring schematics
Setup and Adjustment
To set up and adjust the actuator, use the following procedure:
1. Set up and adjust the electrical travel switches and manual travel stops. See Electrical Travel
Switches and Manual Travel Stop Adjustments
2. Set the potentiometer. See Setting the Potentiometer.
3. Calibrate the servo. See Calibrating the Servo
Electrical Travel Switches and Manual Travel Stop Adjustments
You must set the electrical travel switches to trigger prior to reaching the mechanical travel stops.
The travel switches are labeled for open and close. The cams are color-coded (green for open; red
for closed).
Manual travel stops are designed to prevent manual overtravel, not to stall the electric motor. The
travel stops have an adjustment range of approximately 10 degrees.
Figure 6: Setting the travel timit switches
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Setting Travel Limit Switches
If the unit came assembled to a valve, the switches have been factory-set and DO NOT need
adjustment. Johnson Controls uses cam design along with 2 SPDT mechanical switches to set the
open and closed position of the valve. The green cam actuates the open switch when the actuator
reaches the open position.
Similarly, the red cam actuates the ‘closed’ switch when the actuator reaches the ‘closed’ position.
Standard factory setting of the travel limit switches means 90° travel between open and close
positions. Cams for each switch are adjustable for applications where less than 90-degree travel is
desired between the open and closed positions.
Complete the following procedure to adjust the travel limit cams.
Note: For Housing Size 130, 180, ignore steps 1 and 10.
1. Remove the indicator rotor by pulling away from the indicator shaft as shown in Figure 6.
2. Manually operate the actuator clockwise until the valve reaches the desired closed position.
3. Loosen the cam locking screw shown in Figure 8.
Note: It is possible that the rotation of one cam may move the other cam. If this occurs,
hold the other knobs or cams during adjustment.
4. Rotate the red cam adjustment knob by hand or with a flat head screwdriver until the red cam
lobe just activates (depresses) the ‘closed’ switch from a clockwise direction.
Note: If fixed auxiliary switches are installed, the auxiliary cam activates prior to the main
cam.
5. Tighten the cam locking screw.
6. Manually operate the actuator counterclockwise until the valve reaches the desired open
position.
7. Loosen the cam locking screw.
8. Rotate the green cam adjustment knob until the green cam lobe activates (depresses) the open
switch from a counterclockwise direction.
9. Tighten the cam locking screw.
10. Place the indicator rotor back on the indicator shaft.
Setting the Potentiometer
1. Manually operate the actuator handwheel until the unit is in the fully closed position.
2. Rotate the black potentiometer drive gear adjustment knob to barely engage the
potentiometer gear segment at the closed position.
3. Manually operate the actuator to the fully open position.
4. Fine-tune the potentiometer adjustment at this end to equalize the difference between the
ends. The potentiometer gear segment should maintain engagement with the drive gear
throughout full actuator travel.
Calibrating the Servo
Note: The Servo NXT is not remotely controllable during the autocalibration sequence. If
autocalibration needs to be aborted, pull the handwheel.
Autocalibration mode is entered by pressing and holding the Autocalibration button for at least
three seconds. Entering Autocalibration mode starts the autocalibration sequence: a series of
commands performed by Servo NXT on the actuator to determine the operating points. During
the autocalibration sequence, the Servo NXT should be monitored to ensure it operates correctly.
The product settings’ indicators change state to show that autocalibration has been entered, and
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continue to flash at the end of travel until autocalibration completes. Upon completion of the
autocalibration sequence, the product settings’ indicators return to normal.
If the fault indication lights illuminate during autocalibration, then the autocalibration sequence
could not be successfully completed. Refer to the troubleshooting section for more information.
No other operating modes can be entered during autocalibration, and entering autocalibration
mode overrides any previous mode of operation.
Accessories
External Feedback Potentiometer for Actuators without Servos
Potentiometers for external feedback are available for field installation on VA9072, VA-9073,
VA-9074, VA-9075, VA-9077, and VA-9078 actuators.
Figure 7: Potentiometer for VA-907x series actuators
Important: In special instances where dual potentiometers are required (such as when a
servo is installed and an external feedback potentiometer is also required), you must make
modifications to the switch plate - including locating, drilling, and tapping two new mounting
holes. Consult the local Johnson Controls representative for instructions.
Contents of the Feedback Potentiometer Kit
• one potentiometer assembly
• two No. 6 cross-drive pan-head screws
• two No. 6 internal lock washers
• one 10-point terminal strip
• one terminal strip marker for auxiliary switches and/or feedback potentiometer
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• one small wiring diagram sticker for the additional potentiometer
Tools Required
For terminal wiring: 3/16 in. (5 mm) blade screwdriver
For potentiometer mounting screws: No. 2 Phillips screwdriver
Installation Procedure
1. Install the potentiometer next to the camshaft, use the two threaded holes provided.
2. Mount the potentiometer in the correct orientation with its gear centered so that it meshes
with the potentiometer drive gear.
3. Push the assembly towards the cam to mesh the potentiometer gears, and tighten the
mounting screws.
Figure 8: Installing the Feedback Potentiometer
4. Move the wiring from the six-point strip to the new terminal strip, reconnecting the wiring in
the same positions.
5. Wire the potentiometer to the terminal strip using the small stick-on wiring diagram
provided.
6. Adhere the wiring diagram sticker to the inside of the cover.
Setting the Potentiometer
1. Manually operate the actuator handwheel until the unit is in the fully closed position.
2. Rotate the black potentiometer drive gear adjustment knob to barely engage the
potentiometer gear segment at the closed position.
3. Manually operate the actuator to the fully open position.
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