Duff-Norton SK6905-100-1 - Manual (Page 7)

3-1. A.C. Motor
This motor is an intermittent duty type motor having a
five minute rating. Since the motor draws almost the
same amperage at no load as a full rated load, it only
takes 5 minutes of continuos running, regardless of how
light the load may be, before the thermal overload relay
cuts out. It then takes about 10 minutes before the motor
cools sufficiently for the thermal relay to close. Make
sure that the duty cycle to which the actuator is subjected
is not too severe for the motor. The rear end bell of the
motor has a rubber grommet, which when removed,
exposes a
1 / 2 ” NPT threaded hole.
3-2. Voltage Supply
Avoid using a low voltage supply for the 115 volt motor.
All wiring, switches, etc. must be of sufficient capacity
to carry the required current. (Actuator capacity may be
reduced at low voltages.)
3-3. Clevis Pins
The axis of the clevis pins should be parallel so that the
actuator can pivot without binding. A few drops of oil
should be used on the clevis pins.
WARNING
The actuator is not recommended for use in
applications where it can be jammed. Examples of
jamming include overtraveling the limit switches and
thus jamming the nut and screw internally at the
extreme ends of the stroke, and driving the actuator
against an immovable object and thus overloading the
actuator severely. The actuator can jam a limited
number of times without damage. Therefore, consult
Duff-Norton Engineering if jamming is expected.
Do not operate actuator before setting limit
switches.
Some actuator external surface temperatures
may reach 230˚F at or near maximum allowable duty
cycle.
SECTION III
OPERATIONAL PRECAUTIONS
7