Positioner Mounting; Mounting On 1250, 1250R, 3024S And Gx Actuators - Fisher 3660 Instruction Manual

3660 and 3661 Positioners
September 2015

Positioner Mounting

Mounting on 1250, 1250R, 3024S, and GX Actuators
During the following mounting procedures, refer to figures 3, 24, and 25 for key number locations.
Figure 3 shows keys 64 through 78 and 101 through 104. Other key numbers are shown in either figure 24 for the
3660 positioner or figure 25 for the 3661 positioner. Two mounting methods are available, center‐bolt mounting and
clamp mounting.
1. Determine the positioner mounting configuration from figure 2. The actuator size, actuator travel, and positioner
action must be known. If center‐bolt mounting is desired, be certain the actuator is equipped with tapped holes in
the posts.
2. Thread the hex head screws with washers (keys 69 and 70) several turns into the stem connector. The feedback
plate (key 68) is reversible and must be positioned so that the pilot shaft (key 19A) will operate correctly in the slot
of the feedback plate. For actuator travels between 20 and 30 mm (0.787 and 1.18 inches) (for 3024S actuators,
travel ranges between 16 and 32 mm), position the feedback plate so the long portion of its slot, when bolted to
the stem connector, is closest to the positioner as shown in figure 4. For travels greater than 30 mm (1.18 inches),
reverse the position of the feedback plate as shown in figure 4.
a. For size 30 and 34 actuators with all travels and for size 45 actuators with travel greater than 30 mm (1.18
inches), position the feedback plate (key 68) between the stem connector and washers and tighten the hex head
screws (key 69).
b. For size 45 actuators with travel between 20 and 30 mm (0.787 and 1.18 inches) (16 and 32 mm for 3024S
actuators), attach the feedback adaptor (key 103) to the feedback plate (key 68) using machine screws,
lockwashers, and wedge nuts (keys 102, 101, and 104). The feedback plate and the wedge nuts must be
assembled as shown in the lower right portion of figure 3. Use the mounting holes in the feedback adaptor and
position it as indicated in figure 4. Then, position the feedback plate between the stem connector and washers
and tighten the hex head screws (key 69).
3. Unscrew the two machine screws (key 24), and remove the positioner cover (key 21).
Center‐Bolt Mounting (GX Actuator)
a. As shown in figure 5, a thin knockout section is cast across the mounting hole in the housing. Check to make
certain this knockout section has been removed. If the knockout section has not been removed, use a punch to
knock it out.
b. Attach the positioner to the actuator using a sealing washer and hex head screw (keys 71 and 72).
c. Install the feedback lever assembly and range spring.
Clamp Mounting
a. Install a hex nut (key 66) on one end of each of two studs (key 65). Turn the nuts all the way to the end of the
threads.
b. Thread the end of each stud (key 65), (the end with hex nut—key 66), into the back of the positioner housing
(key 1) as far as the studs will go. Tighten both nuts against the housing.
c. Set the actuator at mid‐travel using a manual loading regulator.
d. With the finger end of the bracket (key 64) toward the positioner pressure connections as shown in figure 3,
place the bracket and washers (key 67) over the studs (key 65). Thread the hex nuts (key 66) several turns onto
the studs.
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Instruction Manual
D101402X012