SERIES 70 ELECTRIC ACTUATOR
Installation, Operation, and Maintenance Manual
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10.2.1 Heater Installation Procedures
WARNING
Turn off all power and lockout/tag out service panel before installing or modifying
any electrical wiring.
The heater is mounted through a hole provided in the switch plate.
1 . Place the heater snugly into its mounting bracket until approx . 1/2" to 1”
[13mm to 25 mm] is left above the bracket .
2 . Slip the heater into its mounting hole .
3 . Align the fastening hole in the bracket with the threaded screw hole in the plate
and fasten the heater to the switch plate .
4 . Connect the heater wires to the terminal strip as indicated on the wiring
diagram .
10.3 Torque Switches
Mechanical Torque switches are a factory installed and calibrated option available
for all Series 70 actuators. Installation is simple, but due to the requirement for
special calibration equipment, it is not available for field installation. Modifying the
factory torque setting voids the actuator warranty. Removal of the switch plate
invalidates factory calibration
The worm is pinned to the worm shaft, which is held in position with a stack of disc
springs at both ends. The torque transmitted through the worm to the output worm
gear acts directly against the disc springs, which compress proportionately. The
worm and worm shaft shift axially as a result.
A specially designed drive lever and pin is incorporated into a groove on the worm,
providing the profile for the torque switching mechanism. A drive lever & pin rides
in the worm gear torque sensor groove, and in turn drives a cam. The cam then
actuates its electrical switch, which interrupts the power to the motor winding
when the torque exceeds the setting. The motor can still be powered to run in the
opposite direction. When powered in the opposite direction, the tripped torque
switch will release automatically.
NOTICE
Torque switches are not field adjustable. Adjustment of torque switches in the field
will void warranty.
Removal of switch plate with torque switches in the field will void warranty.
