Flowserve L120-85 Actuator - Manual (Page 19)

8. Before operating the actuator, depress and turn the Clutch Screw
CCW one quarter turn to the spring release position.
Insert a screwdriver into the Intermediate Shafts and “rock”
them CW
and CCW a few times to ensure all the
gearing is seated well.
4.6 Torque Switch Setting
and Wiring
c WARNING: Hazardous Voltage. Turn power OFF before
opening the Electrical Compartment Cover or making any
adjustments to the Torque Switch.
NOTE: Removal or modification of the Torque Switch Limiter Plate
will void the actuator warranty. Do not exceed the torque setting
indicated by the Torque Switch Limiter Plate without contacting the
Limitorque Customer Service Department.
The L120-85 unit is equipped with a double-acting Torque Switch
that has been factory preset according to the required torque value
provided by the valve manufacturer or other associated equipment
supplier. Further Torque Switch adjustment should not be required;
however, the Torque Switch may be reset from positions 1 through
5 (5 being the highest input torque requirement) by adjusting the
Torque Switch Adjustment Screws unless it is limited by the Limiter
Plate. See figure 11 for Torque Switch nomenclature.
4.6.1 Basic Theory of Operation
As torque is developed by the actuator, the Worm moves axially and
causes compression on the Spring Pack Assembly (components of
the Worm Shaft Assembly (piece 15)). The Spring Pack Assembly
is calibrated so that a given amount of spring compression equates
to a given amount of output torque. Axial Worm Shaft Assembly
movement causes the Torque Switch Shaft (piece 300-13) to move,
therefore engaging the Torque Switch measurement device. Once the
Torque Switch is properly set, it measures valve, or other equipment,
torque input in the ELECTRIC or MANUAL operating modes.
4.6.2 Setting the Torque Switch
a CAUTION: Installing or adjusting the Torque Switch with the
actuator in a loaded condition will result in loss of torque
protection. Before adjusting or installing the Torque Switch,
place the actuator in MANUAL mode and turn the Hand-
wheel in the direction necessary to release the torque load
on the Worm Shaft Assembly.
NOTE: If Torque Switch replacement is required, be sure to use an
L120-85 Torque Switch rather than replacing with an L120-10 thru
40 Torque Switch. The L120-85 Torque Switch Torque Arm is rotated
10° from the position of the Torque Arm on the L120-10 thru 40
Torque Switch (the red dot on the Torque Switch Shaft indicates an
L120-85 Torque Switch).
Figure 11: Torque Switch Components
ID Limiter
Plate (not shown)
#300-4 Torque Switch
Adjustment
Screws
#300-8 Balancing
Screws Mounting
Screw Hole
Torque Arm
Red dot indicates
L120-85 Torque Switch
Typical OPEN
contact assembly
(18 & 18C)
#300-2 & 300-3
Index Arm
Typical CLOSE
contact assembly
(17 & 17C)
1. Turn all power to the actuator OFF.
2. Loosen the Torque Switch Adjustment Screws (piece 300-4) on
the OPEN or CLOSED side of the Torque Switch.
3. Move Index Arm (piece 300-2 or piece 300-3) to desired torque
setting. The higher number indicates an increased torque and/or
thrust output requirement.
4. Tighten the Torque Switch Adjustment Screws (piece 300-4).
5. Turn power ON and operate the valve electrically to seat the valve
or other device and to ensure tight shut-off.
4.6.3 Balancing the Torque Switch
If the Torque Switch has been removed from the unit or if you are
installing a new Torque Switch, it must be rebalanced using the fol-
lowing procedure:
1. Ensure that the actuator is in MANUAL mode and the load is
removed from the Worm Shaft Assembly.
2. Make note of the current OPEN and CLOSED Torque Switch set-
tings before reinstalling the Torque Switch.
3. Loosen Torque Switch Adjustment Screws (piece 300-4) and
position both Index Arms (piece 300-2) and (piece 300-3) at the
1 setting; tighten the Torque Switch Adjustment Screws. Make
sure the Index Marks are aligned. See figure 15.
4. Loosen Balancing Screws (piece 300-8) and install the Torque
Switch. When properly installed, the base of the Torque Switch
1
Limitorque L120-85 Installation, Operation and Maintenance FCD LMENIM1202-00 – 11/05
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