4 torque switch, 1 setting torque switch – Flowserve L120 Series Limitorque Actuation Systems User Manual

Page 11

Limitorque Actuation Systems L120 Series FCD LMENIM1201-04-AQ – 05/15

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4.4 Torque Switch

The torque switch is designed to protect the actuator in open and close directions.

CAUTION: Disconnect all incoming power before opening limit switch compartment or working on
the torque switch.

• Do not use abrasive cloth to clean the contacts on the torque switch.
• Do not torque seat 90° operation valves nor run them against the stops. This may cause damage

to the valve.

NOTE: If the actuator has “torqued out,” release torque buildup by operating the actuator manually.

4.4.1 Setting Torque Switch

The torque switch was set at the factory according to customer-supplied information regarding neces-
sary torque or thrust output that was provided at the time of the order. However, if the setting needs to
be adjusted, perform the following procedure:

CAUTION: A torque switch limiter plate is provided on most actuators.

• Removal or modification of the torque switch limiter plate will void the actuator warranty.
• Do not exceed the setting indicated by this plate without contacting the Limitorque service

department.

• Installing or adjusting the torque switch with the actuator in a loaded condition will result in a loss

of torque protection.

Item letters correspond to Figure 4.1.

1. Place the L120 actuator in manual mode.

2. Release the load on the wormshaft spring pack.

3. For open and close directions, loosen Screw (A) and move Pointer (B) to desired position. A higher

number indicates a high torque and/or thrust output.

4. Tighten Screw (A).

5. Operate the valve electrically to seat valve and to ensure tight shutoff.

6. Rebalance torque switch if required.

Figure 4.1 – Microswitch-Style Torque Switch and 600 Volt Torque Switch

Mounting

Screw

Index Marks

Maximum Stop

Setting Plate

Balancing

Screws

600 Volt Torque Switch

B A

Microswitch-Style Torque Switch