Koso REXA Electraulic Xpac, Installation And Operation Manual

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Xpac
Installation Manual -- Version 5.1 (5/08)
40
REXA
Electraulic Actuators & Drives
from another circuit at the breaker panel. Otherwise, install a line
filter. Be sure the filter is rated for the proper current and voltage.
CONTROL SIGNAL
Although milliamp control signals are generally not noisy, it is possible
for this signal to be corrupted by an outside source. At the control
enclosure, replace the normal control signal with a hand held, battery
powered current source. If operation is stable, then better shielding
of the control signal may be needed. The control signal should not
be run within a conduit containing a main power feed or other high
power cables. The shield of the control signal should be terminated
at the control system ground and not at the control enclosure.
ACTUATOR POSITION FEEDBACK
If the feedback and motor power cable are in the same conduit, try
removing one of the cables. The elimination or reduction of noise
may indicate that separate conduits are required.
7.2.3 Noise Pick-up On Surrounding Equipment
Although it is not common, there have been situations where noise is
picked up on surrounding equipment from the
REXA
actuator. The
noise is generated by the frequency at which the DC Motor Driver
runs the stepper motor. Generally, the noise is eliminated by running
the motor power cable in metallic conduit. Another possibility is
noise being fed through the AC power line. This can be eliminated by
changing the main power circuit or incorporating an AC line filter.
7.3 Mechanical Restriction/Binding
Most mechanical restrictions are an application or mounting related
problem. Any binding will be indicated by erratic motion, slower
speed or restriction of travel. The problem could lie in the actuator,
the device being driven or misalignment between the two.
7.3.1 Lateral Misalignment
Any noticeable bending of the actuator stem or driven device (valve)
stem should be immediately corrected. Not only is operation impaired,
but damage to the actuator seals and bushings or the valve packing
and stem may occur.
The key to quiet operation is a reliable
earth ground and keeping the ground-
ed shield as short as possible within
the control enclosure.