6
Section III
Operation Precautions
3-1. Motor
The motor used on this actuator has a very high power
output for its size. Consequently, heat generation in the
motor is more rapid than in more conventional motors.
Duty cycle limitations must be recognized at all times,
whether or not the actuator is loaded.
Motors are equipped with thermal protectors to guard
against winding burnout. Once tripped , it may take 10
– 15 minutes for the motor to cool sufficiently to reset
the thermal protector. Repeated thermal trips can be an
indicator of excessive load or duty, low voltage, or weak
capacitor(AC only).
wARNiNG
When operated near duty limits, external motor tem-
perature may be hot enough to cause burns. Actuator
should be installed with appropriate precautions to
prevent injury to personnel.
3-2. Clevis Pins
The clevis pins must be maintained parallel to each
other during the full stroke of the actuator. Side loading
or torquing as a result of non-parallel clevises can cause
serious actuator damage. Any creaking noise at the clev-
ises is an indication that pins need lubrication to prevent
pin wear.
3-3. Jamming
cAutioN
Actuators with limit switches have no inherent me-
chanical overload protection. Repeated jamming of
the actuator, internally or against an external stop, will
result in very rapid wear and eventual failure. Be sure
that limit switches are functioning properly to stop the
actuator within its stroke limits.
No-load operation will produce additional drift. Limit
switches should be set far enough from ends of stroke
to accommodate this if no-load operation is antici-
pated.
Actuators with clutches have a degree of protection
against internal or external jamming or overloading;
however, extended slipping of the clutch will cause
accelerated wear and premature actuator failure. To
provide acceptable long-term operation at rated load,
clutches are set somewhat above rated load. Do not
depend on the clutch to gage an acceptable load.
Clutches are not adjustable for wear.
