Mea Hawk - Page 42

MEA INC
2600 American Lane | Elk Grove Village, IL 60007 | USA
T +1 847 766 9040 | F +1 847 350 1951
COMPLETE CONTROL
www.meaincorporated.com
MEA Incorporated | Hawk Actuator Instruction and Operation Manual
02/2018 42
actuator cylinder seals. To determine the location of the leak, it is
recommended that first the solenoids are replaced, one by one, and
then if the leak-by still persists install an actuator soft goods repair
kit.
Solenoids are hot while actuator
is at rest
Solenoids are hot to the touch
when they are powered. The
center solenoid will typically be
hot during normal operation.
The top and bottom solenoids
would be hot during frequent
actuator movement.
The center solenoid will typically be hot during normal operation
and is not a cause for alarm. The top and bottom solenoids may
become hot due to frequent actuator movement, but should cool as
the actuator is at rest. If the top and bottom solenoids continue to
be hot while the control signal is constant it may indicate that the
actuator is unable to hold a position due to internal leak-by
somewhere in the hydraulic fluid system. In this case review the
"Actuator cycles or is unable to hold a position" troubleshooting
entry for possible remedies.
HPS relief valve is venting
hydraulic fluid
The hydraulic fluid system is
overfilled, the pump is cavitating,
or there has been a solenoid
failure
If the hydraulic fluid emitted from the HPS relief valve appears clear
in color it often indicates that the hydraulic fluid system is overfilled
with fluid. Fully stroke the actuator several times to purge the
excess fluid.
If the hydraulic fluid emitted from the HPS relief valve appears
"foamy" or white in color it often indicates that cavitation is occuring
in the actuator pump. Cavitation is most often caused by a hydraulic
fluid system that is underfilled with fluid. Follow the Hydraulic
Power Source (HPS) & Actuator Fluid Fill Procedure to properly
purge the hydraulic fluid system of air.
If a solenoid is improperly wired or otherwise not functioning it
could prevent the pump from moving fluid through the actuator as
intended. "Dead heading" the pump in this manner may also cause
cavitation which could cause hydraulic fluid that appears "foamy" or
white in color to be emitted from the HPS relief valve.
Motor is running, but the
actuator is not moving
Solenoids are not functioning or
the pump suction check valve is
damaged
If a manual override is installed, use the override to stroke the valve
and confirm that the actuator isn't physically prevented from moving
by debris in or damage to the valve/damper.
After valve/damper movement is verified, confirm that the power
supply wiring to the solenoids is correct and that they are energized.
Solenoids will be warm, or even hot, to the touch when energized.
If the solenoids are working properly, the problem may lie with the
pump suction check valve. It is possible that dirt, debris, or a seal
from elsewhere in the hydraulic fluid system is preventing the check
valve from closing properly. Problems with pump suction check
valves often occur after dirt or debris was introduced to the
hydraulic fluid system after a rebuild.
Actuator stroke speeds have
become slower
The pump is slipping
Over time general wear and tear may cause pump slip to increase.
This can lead to lost pump efficiency and actuator speeds will
become slower as a result.