Torque Switch Operation
Select HRSN3 units have torque switches to protect the actuator and any attached equipment from possible damage
which can occur in a high torque event. In such an event the valve or damper being driven encounters some blockage
or impediment to travel. In the case of an actuator without torque switches, the actuator will attempt to drive until it
Torque Switch cams and switches are shown
in the normal operating position.
Upper torque switch and
cam for actuator drive CW
rotation
Lower torque switch and
cam for actuator drive
CCW rotation
Upper cam has rotated
counter clockwise from its
neutral position and has
engaged the switch.
Torque Switch cams shown with the
upper cam tripping the upper switch
(Actuator was driving CW before this trip)
WARNING –
Torque switches are factory set and are NOT ADJUSTABLE.
Changing these settings will void the actuator warranty.
either reaches the end of travel or (likely) the motor
overworks and trips on a thermal overload. Units
with torque switches will cease supplying power
to the motor when a high torque event occurs.
Torque Switch (Normal Mode)
1. In normal operating mode, the torque switch
and drive cam are in the neutral position
shown in the photo.
2. Internal gearing in line with the output drive
provide the rotational action for the cams.
3. Upper torque switch protects CW rotation.
4. Lower torque switch protects CCW rotation.
Torque Event (CW)
1. The photo at left shows a high torque event in
the CW direction
2. The torque switch CW drive cam (upper) and
switch are in the tripped position.
3. When the torque switch trips, it immediately
cuts off power fl ow to the motor for that
direction of travel.
Torque Event (CCW)
1. The photo at left shows a high torque event in
the CCW direction
2. The torque switch CCW drive cam (lower) and
switch are in the tripped position.
3. When the torque switch trips, it immediately
cuts off power fl ow to the motor for that
direction of travel.
Lower cam has rotated
clockwise from its neutral
position (above) and has
engaged the switch.
TORQUE SWITCHES
Torque Switch cams shown with
the lower cam tripping the lower
switch (Actuator was driving CCW before
this trip)
USE ONLY FLO-TITE GENUINE REPLACEMENT PARTS
ELo Rev C ECR 044V
Page
7
of 28
www.flotite.com
