Johnson Controls VA-9070 Series Service manual

1VA-9070 Series Electric Rotary Actuators for Two-Position and Modulating
Service Technical Bulletin
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Internal and External Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Electrical Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Mechanical Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Manual Override Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Pre-installation Storage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Mounting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Multiple Actuator (Parallel) Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Setup and Adjustment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Electrical Travel Switches and Manual Travel Stop Adjustments . . . . . . . . . . . . . . . . . . . . . 8
Setting Travel Limit Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Setting the Potentiometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Calibrating the Servo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
External Feedback Potentiometer for Actuators without Servos . . . . . . . . . . . . . . . . . . . . . 10
Contents of the Feedback Potentiometer Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Tools Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Installation Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Setting the Potentiometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Troubleshooting Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Actuator Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Servo Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Red LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Disassembly and Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
VA-9070 Series Electric Rotary Actuators for
Two-Position and Modulating Service
Technical Bulletin Code No. LIT-977325
Issued May 2018

VA-9070 Series Electric Rotary Actuators for Two-Position and Modulating Service Technical Bulletin2
General Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Tools Required. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Procedure for VA-9072 Actuators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Procedure for VA-9075, VA-9076, VA-9077, VA-9078, VA-907A, and VA-907B Actuators 23
Appendix A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
VA-9072 Actuators. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
VA-9075 Actuator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
VA-9076, VA-9077, VA-9078, VA-907A, and VA-907B Actuators . . . . . . . . . . . . . . . . . . 31
Appendix B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

VA-9070 Series Electric Rotary Actuators for Two-Position and Modulating Service Technical Bulletin 3
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.

VA-9070 Series Electric Rotary Actuators for Two-Position and Modulating Service Technical Bulletin4
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 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.

VA-9070 Series Electric Rotary Actuators for Two-Position and Modulating Service Technical Bulletin 5
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
Connect the actuator to field wiring:
1. Remove the metal conduit plug for the power connection. Each actuator has
two conduit entries (one for power and one for control).
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.
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.
Figure 1 shows typical field wiring for a two-position actuator, whereas Figure 22
shows typical field wiring for a modulating actuator.

VA-9070 Series Electric Rotary Actuators for Two-Position and Modulating Service Technical Bulletin6
Figure 1: Typical Wiring Diagram of VA-9070 Series Two-Position Electric Rotary Actuator
RED
RED
BLUE
BLUE
A
B
C
D
CLOSE N.O.
(VOLTAGE FREE)
OPEN N.O.
(VOLTAGE FREE)
COM
COM
COM
N.O.
N.O.
N.O.
N.O.
N.O.
N.C.
N.C.
N.C.
N.C.
N.C.
AUX OPEN
OPEN
GREEN
CAM
RED
CAM
COM
CLOSE
AUX CLOSE
OVERRIDE SW
COM
1
2
3
4
5
6
7
8
9
YELLOW
BLUE
BLUE
BLUE
RED
RED
RED
YELLOW
HEATER
Ground
Ground
Open
Close
For Heater
Only
Close
Open
Neutral
120 VAC
Blue
Red
Ye ll ow o r
Black
OC
N
Motor
FIG:977319_Fig2

VA-9070 Series Electric Rotary Actuators for Two-Position and Modulating Service Technical Bulletin 7
Figure 2: Typical Wiring Diagram of VA-9070 Series Modulating Electric Rotary Actuator

VA-9070 Series Electric Rotary Actuators for Two-Position and Modulating Service Technical Bulletin8
Multiple Actuator (Parallel) Wiring
Use a multiple pole switch to connect two VA-9070 Series electric actuators. See
the Correct Wiring schematic in Figure 1.
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 3.
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 the
Electrical Travel Switches and Manual Travel Stop Adjustments section in this
document.
2. Set the potentiometer. See the Setting the Potentiometer section in this
document.
3. Calibrate the servo. See the Calibrating the Servo section in this document.
Figure 3: Correct and Incorrect Wiring Schematics
Neutral Live
Open
Open
Motor Motor
Close
Close
DPDT
Switch
Field
Wiring
Actuator A Actuator B
Neutral
Live
Open
Open
Motor Motor
Close
Close
Field
Wiring
SPDT
Switch
Actuator A
Actuator B
Correct Wiring Incorrect Wiring
FIG: wir_crrct_incrrct

VA-9070 Series Electric Rotary Actuators for Two-Position and Modulating Service Technical Bulletin 9
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.
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 4.
2. Manually operate the actuator clockwise until the valve reaches the desired
closed position.
Figure 4: Setting the Travel Limit Switches

VA-9070 Series Electric Rotary Actuators for Two-Position and Modulating Service Technical Bulletin10
3. Loosen the cam locking screw shown in Figure 6.
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
continue to flash at the end of travel until autocalibration completes. Upon
completion of the autocalibration sequence, the product settings’ indicators return
to normal.

VA-9070 Series Electric Rotary Actuators for Two-Position and Modulating Service Technical Bulletin 11
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-9076, VA-9077, and VA-9078
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.
FIG:ptntmtr
Figure 5: Potentiometer for VA-907x Series Actuators

VA-9070 Series Electric Rotary Actuators for Two-Position and Modulating Service Technical Bulletin12
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
• 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.
4. Move the wiring from the six-point strip to the new terminal strip,
reconnecting the wiring in the same positions.
FIG:instl_ptntmtr
Figure 6: Installing the Feedback Potentiometer

VA-9070 Series Electric Rotary Actuators for Two-Position and Modulating Service Technical Bulletin 13
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.
4. Fine-tune the potentiometer adjustment at this end to equalize the difference
between the ends. The potentiometer gear segment should remain engaged
with the drive gear throughout full actuator travel.
Troubleshooting Procedures
Actuator Troubleshooting
See Table 1 for actuator troubleshooting information.
Table 1: Actuator Troubleshooting Chart (Part 1 of 2)
Problem Possible Cause Solution
Actuator does not
operate.
Override is engaged. Push handwheel in all the way.
Wiring is incorrect. Check wiring and power supply.
Actuator motor has reached its thermal
shutdown temperature
Allow time to cool.
Actuator operates in
reverse directions.
Field wiring is reversed. Rewire field wiring.
Actuator does not
fully close valve or
open valve
Limit switches trip. Readjust travel limit switches.
Mechanical travel stop is stopping actuator. Adjust mechanical travel stops.
Valve torque requirement is higher than
actuator output.
Manually override out of seat; try angle
seating or larger actuator.
Optional torque switches activating Valve torque exceeds actuator torque rating
- consult factory
Voltage power supply is low. Check power source
Engaging override
handwheel does not
shut off motor.
Override pin is corroded or damaged. Clean and check for smooth operation of
the override switch pin.
Override switch is damaged. Replace switch.

VA-9070 Series Electric Rotary Actuators for Two-Position and Modulating Service Technical Bulletin14
Servo Troubleshooting
Refer to the actuator manual before adjusting or replacing any actuator
components. Before testing or acting on any possible issues, check for any active
faults.
WARNING: Risk of electric shock
Turn off all power and lockout/tag out service panel before installing or modifying any
electrical wiring.
Table 2: Servo Troubleshooting Chart
Disengaging
override handwheel
does not restart
motor.
Not completely disengaged. Push handwheel in as far as possible so
that no yellow shows.
Override pin is damaged and/or does not
trigger switch.
Replace override pin.
Incorrect wiring of override switch. Check wiring.
Motor runs but
worm and gear
segment do not run.
Worm gear segment is not meshing with
worm.
Remove switch plate and inspect; adjust
travel stops to prevent problem.
Pin/Key on Worm/Motor drive gear
sheared.
Replace Pin/Key on drive gear.
Corrosion inside
actuator.
Condensation forming. Test heater wiring; should have constant
power.
Water leaking in. Check all seals and possible water entry
through conduit.
Problem Possible Cause Solution
Servo NXT does not
turn on when power
is applied
Fuse is blown Verify and replace fuse
Servo NXT is incorrectly wired Verify wire connections against the wiring
diagram
Servo NXT is not receiving power Test the Input Power connection with a
multimeter or oscilloscope
Power is not correct Check the provided power against the
voltage listed for the Servo NXT and
actuator
Actuator moves
back and forth near
setpoint (hunting)
Deadband is too narrow Increase the deadband setting
Excessive noise on the signal lines Use an oscilloscope to test for the presence
of EMI.
Utilize EMI reducing techniques to mitigate
the issue.
Servo NXT not
responding to
command signal
Servo NXT in local mode If local control is being used, ensure the
local control station is not active or is set to
remote mode.
Servo NXT in manual or autocalibration
mode
Check the indicators for manual or
autocalibration mode
Servo NXT is incorrectly wired Verify wire connections against the wiring
diagram
Table 1: Actuator Troubleshooting Chart (Part 2 of 2)
Problem Possible Cause Solution

VA-9070 Series Electric Rotary Actuators for Two-Position and Modulating Service Technical Bulletin 15
Some flash codes indicate a warning condition. In a warning condition (such as the
indication of an invalid calibration), the servo recovers automatically. In this case,
default calibration automatically loads. This means the servo will operate, but it
may not be a perfect match to the actuator. If this happens, recalibrate the servo as
soon as possible.
Cmd Signal Fault Command signal does not match input
setting
Adjust the input setting to match the
command signal used
Servo NXT is incorrectly wired Verify wire connections against the wiring
diagram
Servo NXT is not receiving the command
signal
Test the Input Command connection with a
multimeter or oscilloscope
Limit switch fault Both limit switches engaged Adjust actuator cams
Servo NXT is incorrectly wired Verify wire connections against the wiring
diagram
Travel limit switch failure Test the switches to ensure that they
change states when engaged.
Hand wheel fault Hand wheel is engaged Disengage (push in) hand wheel
Servo NXT is incorrectly wired Verify wire connections against the wiring
diagram
Hand wheel switch failure Test the switch to ensure that it is changing
states when engaged.
FB pot fault Potentiometer outside of travel range Operate the actuator to the fully open and
fully closed position, and adjust the
potentiometer position as needed.
Servo NXT is incorrectly wired Verify wire connections against the wiring
diagram
Torque switch fault Torque switch setting enabled with no
torque switches connected
Disable torque switch settings
Torque switch or switches engaged Check the valve and/or actuator for
obstructions.
Servo NXT is incorrectly wired Verify wire connections against the wiring
diagram
Torque switch failure Test the switches to ensure that they
change states when engaged.
Motor stall fault Operational torque is exceeding the torque
rating of the actuator
Check the valve and/or actuator for
obstructions.
Measure the torque required to rotate the
valve and verify against the rated torque
Servo NXT is incorrectly wired Verify wire connections against the wiring
diagram
Fault condition
during
autocalibration
Fault occurring during calibration Operate the actuator to the fully open and
fully closed position, and correct any faults
that occur
Servo NXT is incorrectly wired Verify wire connections against the wiring
diagram
Problem Possible Cause Solution

VA-9070 Series Electric Rotary Actuators for Two-Position and Modulating Service Technical Bulletin16
To recalibrate the servo, press and hold the CALIBRATE button until the green
Status LED flashes rapidly (approximately 2 seconds), then release the
CALIBRATE button. The servo drives the valve to the open and close travel limit
switch settings. When the calibration is complete, the green Status LED resumes
flashing at the normal rate.
Note: If you detect error codes 3, 5, 6, or 7, contact your Johnson
Controls representative for further information.
Table 3: Green LED Warning and Information Flash Codes
Code Description Meaning
1Normal Operation The actuator detects no errors and operates normally.
2Control Signal
Calibration Error
If this error occurs, add or remove jumpers for the input type.
3Feedback
Potentiometer
Error
An invalid feedback potentiometer calibration is detected. To
ensure a valid feedback calibration, ensure that these conditions
exist.
The upper limit calibration is greater than the lower limit calibration.
The difference between the upper and lower limits is at least
3volts.
The feedback potentiometer is not wired backwards.
4Calibration in
Process
The green LED flashes rapidly during this operation.
5Reverse Acting
Warning
This warning indicates that the servo is configured to operate in the
Reverse Acting Mode.
6Split Range 0 to
50% Warning
This warning indicates that the servo is configured to operate in the
Split Range 0 to 50% range mode.
7Split Range 50 to
100% Warning
This warning indicates that the servo is configured to operate in the
Split Range 50 to 100% range mode.
8Calibration in
Process
During a calibration, the LED flashes rapidly at one-half second
intervals. When the calibration is complete, the LED resumes with
the Normal Operation flash code (Code 1) unless another warning
is still pending.

VA-9070 Series Electric Rotary Actuators for Two-Position and Modulating Service Technical Bulletin 17
Red LED
A flashing red LED indicates a fault condition that prevents the actuator from
operating. Correct the fault condition to allow the actuator to resume operating. If
you detect error Code 16, contact your Johnson Controls representative for further
information.
Table 4: Red LED Warning and Information Flash Codes
Code Description Meaning
9Handwheel Is Engaged
(Pulled Outward)
When the handwheel is engaged, the servo can only be
operated manually. This error also occurs if the handwheel
switch is incorrectly connected to the servo.
10 Command Signal
Failure
When the servo is configured to operate in the 0 to 20 mA
mode, an input greater than 20 mA triggers an error. When the
handwheel is configured to run in 4 to 20 mA operating mode,
an input less than 4 mA or greater than 20 mA triggers an
error. The Command Signal is not checked in the 0 to 10 V
mode.
11 Feedback
Potentiometer Failure
If the feedback potentiometer cannot be detected, or if in the
fully closed or fully open position and the feedback
potentiometer is at the end of its travel, an error is detected.
12 Open and Close Limit
Switch Failure
When both the open and close limit switches are
open-circuited at the same time, an error is detected.
13 Open Torque Limit
Reached
The open torque limit switch has been tripped or the open
torque limit switch is incorrectly connected to the servo.
14 Close Torque Limit
Reached
The close torque limit switch has been tripped or the close
torque limit switch is incorrectly connected to the servo.
15 Feedback
Potentiometer Wired in
Reverse
This check is made only during the servo autocalibration. The
feedback potentiometer is wired in reverse when, at the
completion of the calibration, the feedback potentiometer
value at the fully open position is less than the value at the
fully closed position. To clear the error, turn off the power to
the servo, correct the feedback potentiometer wiring, turn on
the power to the servo, and complete the autocalibration.
16 General Servo Failure If after cycling the power to the servo, this error persists,
contact your local Johnson Controls representative for
assistance.
17 Calibration Error This flash code is displayed after a failed calibration for
3 seconds. See Code 2 and Code 3 in Table 3 for more
information.

VA-9070 Series Electric Rotary Actuators for Two-Position and Modulating Service Technical Bulletin18
Disassembly and Assembly
General Information
VA-9070 Series actuators are differentiated into four groups, according to size:
• VA-9072 actuators
• VA-9075 actuators
• VA-9076, VA-9077, and VA-9078 actuators
• VA-907A and VA-907B actuators
Tools Required
Table 5: Basic Tools Common to All Actuators
Item Tool
Terminal Connections, Cam Adjustment Screwdriver, 3 to 4 Tip Blade
All Switches, Terminal Strip, Torque Switch
Plate
Screwdriver, No. 1 Phillips
Switch Plate Screws, Capacitor Screwdriver, No. 2 Phillips
Servo Trimmer Potentiometers Screwdriver, Blade for Trim Potentiometers
Table 6: Basic Tools for VA-9072 Actuators
Item Tool
Mounting Nuts Wrench, 1/2 in. (13 mm)
Cover Captivated Cap Screws Hex Key, 1/4 in. (6 mm)
Travel Stop Adjusting Studs Hex Wrench, 1/8 in. (3 mm)
Travel Stop Jam Nuts Wrench, 7/16 in. (11 mm)
Motor Mount Socket Flat-Head Cap Screw Hex Key, 3/32 in. (2 mm)
Motor Mount Socket-Head Cap Screw Hex Key, 9/64 in. (4 mm)
Table 7: Basic Tools for VA-9075 Actuators
Item Tool
Mounting Nuts (Small Pattern), Travel Stop
Jam Nuts
Wrench, 1/2 in. (13 mm)
Mounting Nuts (Large Pattern) Wrench, 3/4 in. (19 mm)
Cover Captivated Cap Screws Hex Key, 5/16 in. (8 mm)
Travel Stop Adjusting Studs Hex Key, 3/16 in. (5 mm)
Motor Mount Socket-Head Cap Screw Hex Key, 5/32 in. (4 mm)
Table 8: Basic Tools for VA-9076, VA-9077, VA-9078, VA-907A, and VA-907B
Actuators
Item Tool
Mounting Nuts, Travel Stop Jam Nuts Wrench, 3/4 in. (19 mm)
Cover Captivated Cap Screws Hex Key, 3/8 in. (10 mm)
Travel Stop Adjusting Studs Wrench, 3/4 in. (19 mm) [15/16 in. (8 mm) for
VA907A and VA-907B]
Motor Mount Socket-Head Shoulder Bolt Hex Key, 5/32 in. (4 mm)
Motor Mount Socket-Head Cap Screws Hex Key, 3/16 in. (5 mm)

VA-9070 Series Electric Rotary Actuators for Two-Position and Modulating Service Technical Bulletin 19
Procedure for VA-9072 Actuators
1. Disconnect all power to the actuator and remove the cover. See Figure 7.
2. Disconnect the motor wires from the main terminal block (motor close, motor
open, and neutral).
Figure 7: Two-Position Actuator with Cover Removed

VA-9070 Series Electric Rotary Actuators for Two-Position and Modulating Service Technical Bulletin20
3. Remove the switch plate by unscrewing the seven Phillips mounting screws.
The switch plate should lift out as an assembly with the camshaft attached. See
Figure 7 and Figure 8.
Figure 8: Removing the Switch Plate (Two-Position Actuator)