Autoquip CMD DOCK LIFT - Manual (Page 29)

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PROBLEM POSSIBLE CAUSE AND SOLUTION
Lift does not raise. • The motor rotation for a 3-phase motor may be
reversed. Reverse only two motor electrical leads.
• Check for a line or hose leak.
• Check for oil shortage in the reservoir. Add oil as
necessary (See Oil Requirements in the “Routine
Maintenance” section.)
• The load may exceed the rating. (See the
“Specifications” section.) Remove the excess load.
• The suction filter may be clogged, starving the
pump. Remove and replace the filter. Drain and
replace the oil.
• The suction line may be leaking air due to a loose
fitting. Tighten as needed.
• The breather holes in the reservoir fill plug may be
clogged. Remove and clean.
• The voltage at the motor terminals may be too low
to run the pump with the existing load. Check by
measuring the voltage at the motor terminals, or as
near as possible, while the pump is running under
load. Reading the source voltage or pump-idling
voltage is meaningless. Inadequate or incorrect
wiring can starve the motor when the source
voltage is ample. Correct as necessary.
• The "Down" valve may be energized by faulty wiring
or stuck open. Remove the solenoid and check.
• The motor may be single phasing. Check wiring,
fuses, etc.
• The pump may be seized if motor is humming or
blowing fuses on overload protection devices.
Remove the pump. The pump should be able to be
rotated by hand. Check for cracks in the housing.
• The down solenoid valve stem may be bent,
causing the valve to be stuck open. Replace the
down solenoid valve.
TROUBLESHOOTING ANALYSIS