Emerson Fisher 3710 Instruction Manual page 14

3710 and 3720 Positioners
September 2017
1. See figure 5 for a typical actuator. Remove the actuator travel indicator machine screws, travel indicator, and
actuator cover cap screws.
Note
When removing the actuator cover plate, take care not to change the position of the rod end bearing on the end of the turnbuckle
inside the actuator housing.
2. If necessary, install a new cover plate.
a. Remove the existing cap screws and actuator cover plate from the actuator housing.
b. Remove the retaining ring (e‐clip) and hub from the cover plate.
c. Install the hub and retaining ring into the new actuator/positioner cover plate.
Note
Position the actuator cover plate so the positioner mounting holes on the new cover plate allow placement of the positioner in the
desired orientation.
Actuator cover alignment on the 1052 actuator can be aided by moving the actuator slightly away from its "up" travel stop using a
regulated air source. If the hole alignment cannot be obtained in this manner, temporarily loosen the cap screws that secure the
housing to the mounting yoke and shift the housing slightly. Do not completely travel the actuator while the cover is removed.
Tighten the actuator cap screws before continuing.
3. Position the new actuator/positioner cover plate so the positioner mounting holes on the new cover plate allow
placement of the new positioner in the desired orientation. Secure the new cover plate to the actuator.
4. Install the positioner tie bar (key 42) in place of the travel indicator on the actuator hub.
Note
Before installation of the positioner mounting plate (key 43), review the mounting drawings (figures 4 and 33). Properly align the
positioner mounting plate before attaching the mounting plate to the actuator cover plate. Note that the three positioner
mounting holes must be aligned to match the three mounting screws which will pass through the base of the positioner.
5. If the specific actuator requires a positioner mounting plate (key 43), install the mounting plate using the cap
screws (key 45).
6. Unscrew the four captive cover screws and remove the cover assembly (key 7) from the positioner.
7. See figure 6. Loosen the cam locknut (key 37) and rotate the feedback shaft (key 38) as necessary to align the slot in
the feedback shaft end with the tie bar on the actuator hub. Tighten the cam locknut.
8. Align the positioner with the mounting holes in the new actuator cover plate or positioner mounting plate. Be sure
that the tie bar fits securely into the feedback shaft end slot. Secure the positioner to the actuator cover plate or
mounting plate using the (hex) socket head cap screws (key 46).
9. Before installing the positioner cover, properly align the valve position indicator (standard, low‐profile indicator or
optional beacon indicator). Follow the standard or beacon indicator alignment procedure given in this instruction
manual. Then, install the positioner cover assembly.
14
Instruction Manual
D101728X012