Operation and Maintenance Manual

be exercised since the additional moment load on the antenna from

wind force may be enough to exceed the maximum load rating.

b. Inertia loading must also be considered since, during both

acceleration and deceleration, the torque load on the drive train

mechanism increases. Inertia overload causes slow starting and

commensurate increase in motor current to compensate for the

excessive drive torque required. Faltering, vibration, and exceeding

of the torque rating on deceleration may all result from inertia

overload, causing excessive gear wear and possible tooth breakage.

CAUTION

To avoid damage to the Positioner drive train from inertial overload,

it is vital to apply speed changes slowly whenever an overload is

suspected. This is because inertial torque effects are proportional

to the square of the turntable speed.

2.4 Operation Instructions

CAUTION

Prior to any operation of the Positioner, make sure that no person

or equipment is inside the Positioner rotation area.

a. Set the "SAFE/OPERATE" switch to "OPERATE" position.

b. Set Power Switch on the Controller to the "ON" position - "ON" lamp

will illuminate. The positioner will perform a self-test by slewing in

both azimuth and elevation.

c. Upon completion of the self-test, choose between "LOCAL" operation

(operation by means of the Controller) or "REMOTE" operation

(operation by means of the Computer) by setting the Controller to the

desired mode of operation, using the LOCAL/REMOTE switch. The

Positioner and System are now ready to operate.