Johnson Controls VA-8051 user manual

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Valve and Actuator Manual 977
Actuators and Positioners Section
Product Bulletin VA-8051
Issue Date 0988
VA-8051 Electric Valve Actuator
Floating Control, 50 lb. Force
The VA-8051 synchronous,
motor-driven actuator provides
floating control of valves with up
to 3/4 in. stroke in heating,
ventilating, and air conditioning
applications. This compact,
non-spring return actuator has a
50 lb. force and is compatible
with a 3-wire, 24 VAC signal.
A ± 12 VDC signal from a
DSC-8500 may be used with a
V

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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 move in the proper direction. 2 VA-8051 Product Bulletin

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Wiring is to a terminal strip spring plate off the The coupler should thread labeled DWN (Down), COM valve. Remove the down the stem until (Common) and UP, spring compression approximately 1/8 in. of respectively. Wiring is to the tool if used. thread remains between the terminals labeled R (Retracted coupler and the Palnut. f. Thread the lower spring end), W (Wiper), and S (Stroked plate up the end) for the feedback centerpiece stuffing box potentiometer. to increase spacing (See Fig. 6). betwe

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8. Reverse the actuator and drive it up until it stops on the limit switch. Check to make sure the gap between the lever plate and the molded upper stop is 1/16 in. (.047 to .093 in.). Set with flat washer gage supplied. (See Fig. 5). Repeat steps 6, 7 and 8 until the gap falls into this range when the actuator stops. 9. With the valve driven fully up to hold tension on the stem and coupler, thread the Palnut up the stem until it contacts the coupler. Tighten Palnut to coupler with 1/2 in. and 7

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Repair Information Field repairs must not be made. For a replacement VA-8051, contact the nearest Johnson Controls branch office. Application and Drawing Identification Fig. 3: Isometric Drawing Fig. 4: VA-8051-1 Dimensions in./mm. Fig. 5: Internal View VA-8051 Product Bulletin 5

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Fig. 6: DSC-8500 Application Wiring (Incremental Control with Position Indication or Proportional Control) Controls Group 507 E. Michigan Street P.O. Box 423 Printed in U.S.A. Milwaukee, WI 53202 6 VA-8051 Product Bulletin