Johnson Controls VA-8052, VA-8052-1 User Manual

Valve and Actuator Manual 977
Actuators and Positioners Product Information Section
Technical Bulletin VA-8052
Issue Date 0489
VA-8052 Electric Valve Actuator
The VA-8052-1 motor-driven actuator provides proportional control of valves with up to 3/4 in. lift in heating, ventilating, and air conditioning applications. This non-spring return actuator has a 50 lb force and requires a two-wire, voltage signal (usually 0 to 10 VDC) from the controller, and 24 VAC power.
Installation
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WARNING: Equipment Damage Hazard. Do not drive the VA-8052 actuator unless it is mounted to a valve. This can result in permanent damage to the actuator.
Installation of VA-8052-1 on 1/4 in. and 1/2 in. Stroke Valves
1. Unpack the VA-8052 Actuator and insure that the feedback potentiometer plunger is on top of the coupler arm.
2. Install the valve packing that is provided according to the instructions included with it.
3. Thread the 1/4 in. Palnut, open side down, all the way onto the valve stem.
4. Loosely install the actuator by sliding the actuator yoke between the spring plate and valve centerpiece surface. Finger tighten the spring plate to hold the actuator in place (see Fig. 1).
5. Obtain a source of 24 VAC power and wire to the AC and COM terminals. Wire a source of 0 to 10 VDC to the IN and COM terminals (see Fig. 4). Check to see
© 1989 Johnson Controls, Inc. 1
Part No. 14-761-0, Rev. -­Code No. LIT-977310x
that the stroke potentiometer is fully CCW (see Fig. 1).
6. Thread the knurled coupler onto the valve stem until approximately 1/4 in. of thread remains between the knurled coupler and the Palnut. Note: It may be necessary to pull the valve stem up to meet the coupler or to apply 0 to 10 VDC to position the coupler above the valve stem.
7. Secure the actuator in place by tightening the spring plate with a large screwdriver (see Fig. 2).
8. Stroke the actuator to the stem-up position by applying 0 VDC. Thread the knurled coupler onto the valve stem until the knurled coupler fits snugly.
9. Increase the signal slightly (to 3 to 4 VDC) so that tension on the coupler is relieved. When lever stops moving, thread the knurled coupler on another 1 to 1-1/4 turn.
10. Reduce the signal to zero to stroke the actuator to the stem-up position. The limit switch should click softly at the full stem-up position. If not, repeat step 9.
11. With the valve driven fully up, thread the Palnut up the stem until it contacts the coupler. Tighten the Palnut with a 7/16 in. wrench while holding the nut on top of the coupler with a 1/2 in. wrench.
12. Provide an input signal of 10 VDC to the actuator. After the actuator strokes completely to the stem­down position, slowly adjust the stroke potentiometer CW until the stem just begins to move up. Then adjust the stroke potentiometer CCW until the stem strokes down and the limit switch clicks. Turn the stroke adjustment an additional 1/8 rotation CCW to assure positive full stroke.
13. Drive the actuator fully up and down at least three complete cycles (by alternately applying 0 and 10 VDC), checking to see that the upper and lower limit switches click. Note: The lever plate must not contact the upper stop and the drive coupler must not contact the bottom surface of the actuator yoke (see Fig. 1).
Installation of VA-8052-1 on 3/4 in. Stroke, 2-Way Push Down to Open (PDO) Valves
1 . Unpack the VA-8052
Actuator and insure that the feedback potentiometer plunger is on top of the coupler arm.
2. Install the valve packing that is provided according to the instructions included with it.
3. Thread the 1/4 in. Palnut, open side down, onto the valve stem and all the way to the end of the threads.
4. Loosely install the actuator by sliding the actuator yoke between the spring plate and valve centerpiece surface. Finger tighten the spring plate to hold the actuator in place (see Fig. 1).
5. Obtain a source of 24 VAC power and wire to the AC and COM terminals (see Fig. 4). Wire a source of 0 to 10 VDC to the IN and COM terminals. Check to see that the stroke potentiometer is fully CCW (see Fig. 1).
6. Thread the knurled coupler onto the valve stem until approximately 1/4 in. of thread remains between the knurled coupler and the Palnut. Note: It may be necessary to pull the valve stem up to meet the coupler or to apply 0 to 10 VDC to position the coupler above the valve stem.
Fig. 2: Isometric Drawing of VA-8052
Fig. 3: Internal View of V-3000 Actuator
7. Secure the actuator in place by tightening the spring plate with a large screwdriver (see Fig. 2).
8. Stroke the actuator to the stem-up position by applying 0 VDC. Thread the knurled coupler onto the valve stem until the knurled coupler fits snugly.
9. Increase the signal slightly (to 3 to 4 VDC) so that tension on the knurled coupler is relieved. When the lever stops moving, thread the knurled coupler on another 1 to 1-1/4 turn.
10. Reduce the signal to zero to stroke the actuator to the stem-up position. The limit switch should click softly at the full stem-up position. If not, repeat step 9.
11. With the valve driven fully up, thread the Palnut up the stem until it contacts the coupler. Tighten the Palnut with a 7/16 in. wrench while
holding the nut on top of the coupler with a 1/2 in. wrench.
12. Drive the actuator fully up and down at least three complete cycles, (by alternately applying 0 and 10 VDC) checking to see that the upper limit switch clicks. Note: The lever
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plate must not contact the upper stop and the drive coupler must not contact the bottom surface of the actuator yoke (see Fig. 1).
Installation of VA-8052-1 on 3/4 in. Stroke 2-Way, Push Down to Close (PDC) Valves
1. Unpack the VA-8052 Actuator and insure that the feedback potentiometer plunger is on top of the coupler arm.
2. Install the valve packing that is provided according to the instructions included with it.
3. Thread the 1/4 in. Palnut, open side down, onto the valve stem and all the way to the end of the threads.
4. Loosely install the actuator by sliding the actuator yoke between the spring plate and valve centerpiece surface. Finger tighten the spring plate to hold the actuator in place (see Fig. 1).
VA-8052 Technical Bulletin 3
5. Obtain a source of 24 VAC power and wire to the AC and COM terminals. Wire a source of 0 to 10 VDC to the IN and COM terminals (see Fig. 4). Check to see that the stroke potentiometer is fully CCW (see Fig. 1).
6. Thread the knurled coupler onto the valve stem until approximately 1/8 in. of thread remains between the knurled coupler and the Palnut. Note: It may be necessary to pull the valve stem up to meet the coupler or to apply 0 to 10 VDC to position the coupler above the valve stem.
7. Secure the actuator in place by tightening the spring plate with a large screwdriver (see Fig. 2).
8. Stroke the actuator to the stem-down position by applying 10 VDC. Unthread the knurled coupler CCW on the valve stem until the knurled coupler fits snugly.
9. Decrease the signal slightly (to 6 to 7 VDC) so that compression on the coupler is relieved. When the lever stops moving, unthread the knurled coupler another 2 to 3 turns.
10. Increase the signal to 10 VDC to stroke the actuator to the stem-down position. The limit switch should click at the full stem­down position. If the switch does not click, repeat step 9.
11. With the valve driven fully down, thread the Palnut up the stem until it contacts the coupler. Tighten the Palnut with a 7/16 in. wrench while holding the nut on top of the coupler with a 1/2 in. wrench.
12. Drive the actuator fully up and down at least three complete cycles, checking to see that the lower limit switch clicks. Note: The lever plate must not contact
the upper stop and the drive coupler must not contact the bottom surface of the actuator yoke (see Fig. 1).
Retrofit
To remove the V-3000 actuator, upper spring plate, and spring, refer to Fig. 3 and proceed as follows:
1. Disconnect the air line to the actuator.
2. Remove the actuator by loosening the actuator set screw on the bottom of the lower diaphragm case. Lift the actuator off of the valve.
3. Hold the stem extension firmly with a 9/16 in. box­head wrench and, with a small screw driver, loosen the stem locking screw.
4. For V-3000 Series Valves, compress the spring using the JC 5389 Spring Compression Tool. For V-3800 Series Valves, compress the spring with hand pressure.
5. Using a 9/16 in. box-head wrench, unscrew the stem extension. Lift the spring and upper spring plate off of the valve. Remove the spring compression tool if used.
6. Thread the lower spring plate up the centerpiece stuffing box to increase spacing between the spring plate and the valve center­piece mounting surface.
Calibration
Calibration for 1/4 to 1/2 in. Stroke Valves
The stroke, zero, and span settings are factory calibrated to accept a 0 to 10 volt signal from a controller. To change the factory settings, proceed as follows:
Stroke Adjustment ( See Fig. 1)
1. Adjust the stroke potentiometer fully CCW to maximum. Adjust the span
potentiometer fully CCW to minimum. Adjust the zero potentiometer fully CW to minimum.
2. Provide an input signal of 10 VDC to the actuator. After the actuator strokes completely to the stem­down position, slowly adjust the stroke potentiometer CW until the stem just begins to move up. Then adjust the stroke potentiometer CCW until the stem strokes down and the limit switch clicks. Turn the stroke adjustment an additional 1/8 rotation CCW to assure positive full stroke.
Zero Adjustment
3. Adjust the zero potentiometer fully CCW to maximum.
4. Provide an input signal equal to the desired zero (starting point) value and then wait for the actuator to stroke to the stem-up position and the limit switch clicks.
5. Slowly adjust the zero potentiometer CW until the actuator just begins to stroke.
Span Adjustment
6. Adjust the span potentiometer fully CW to maximum.
7. Provide an input signal equal to the desired full stroke voltage. (This value must be at least 2.5 VDC greater than the zero value.)
8. Slowly adjust the span potentiometer CCW until the actuator is fully stroked to the stem-down position and the limit switch clicks.
Calibration for 3/4 in. Stroke, 2-Way PDO Valves
The stroke, zero, and span settings are factory calibrated to accept a 0 to 10 volt signal from
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a controller. To change the factory settings, proceed as follows:
Stroke Adjustment (See Fig. 1)
1. Adjust the stroke potentiometer fully CCW to maximum. Adjust the span potentiometer fully CCW to minimum.
Zero Adjustment
2. Adjust the zero potentiometer fully CCW to maximum.
3. Provide an input signal equal to the desired zero (starting point) value and then wait for the actuator to stroke to the stem-up position and the limit switch clicks.
4. Slowly adjust the zero potentiometer CW until the actuator just begins to stroke.
Span Adjustment
5. Adjust the span potentiometer fully CW to maximum.
6. Provide an input signal equal to the desired full stroke voltage. (This value
7. Slowly adjust the span potentiometer CCW until the actuator is fully stroked to the stem-down position. The drive coupler must not contact the bottom surface of the actuator yoke.
Calibration for 3/4 in. Stroke, 2-Way PDC Valves
The stroke, zero and span settings are factory calibrated to accept a 0 to 10 VDC from a controller. To change the factory settings, proceed as follows:
Stroke Adjustment (See Fig. 1)
1. Adjust the stroke potentiometer fully CCW to maximum. Adjust the span potentiometer fully CCW to minimum.
Zero Adjustment
2. Adjust the zero potentiometer fully CCW to maximum.
3. Provide an input signal equal to the desired zero (starting point) value and then wait for the actuator to stroke to the stem-up position.
4. Slowly adjust the zero potentiometer CW until the actuator just begins to stroke.
Span Adjustment
5. Adjust the span potentiometer fully CW to maximum.
6. Provide an input signal equal to the desired full stroke voltage. (This value must be at least 2.5 VDC greater than the zero value.)
7. Slowly adjust the span potentiometer CCW until the actuator is fully stroked to the stem-down position and the limit switch clicks.
Wiring
All wiring must be in accordance with applicable electrical code requirements. Input lines to the actuator must be wired correctly for the valve to work.
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CAUTION: Use the
VA-8000-101 Insulator Kit for steam applications, 280°F (138°C) maximum.
Repair Information
Field repairs must not be made. For a replacement VA-8052, contact the nearest Johnson Controls branch office.
Application and Drawing Identification
Fig. 4 -- Typical Application
must be at least 2.5 VDC greater than the zero value.)
Controls Group
507 E. Michigan Street P.O. Box 423 Printed in U.S.A. Milwaukee, WI 53202
Fig. 5 -- VA-8052 Dimensions in./mm
VA-8052 Technical Bulletin 5
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