Autoquip FREIGHTLIFT FLH - Manual (Page 95)

95
PROBLEM POSSIBLE CAUSE AND SOLUTION
Freightlift will not raise
(motor is running or
“humming”).
WARNING!
a safety
device may have been
activated – if you are
not familiar with how
safety devices interact
with the operation of
the lift, you must find
someone who does.
Or, call Autoquip
Customer Service at
888-811-9876
.
 WARNING! The lifting cables may be disconnected or
broken. Check while standing near (but NOT on) the lift
carriage and correct as necessary – once carriage has
been blocked in place.
 The load may exceed the rated capacity of the lift.
Remove any excess load.
 Rotation on the 3-phase motor may be reversed.
Reverse any two motor electrical leads.
 The 3-phase motor may be single-phasing (humming).
Check wiring, fuses, etc.
 Check for a hydraulic oil leak. Correct as necessary.
 Check for oil shortage in the reservoir and add oil as
necessary.
 The breather cap on the reservoir may be clogged.
Remove and clean.
 The suction screen may be clogged, starving the pump.
The screen is attached to the suction line in the tank.
Remove and clean. Drain and replace oil.
 Suction line may be leaking air due to a loose fitting,
causing cavitation. Check fittings. Bleed air from the
system.
 The “DOWN” valve may be energized by faulty wiring or
it may be stuck in the open position. Remove the
solenoid and check.
 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 pump may be seized if the motor is humming,
blowing fuses or overloads. Remove the pump (with the
platform in the lowered position). The shaft should be
able to be turned by hand. Check for cracks in the
housing.
 Heavy Duty PU - The manual down valve may be pulled
open. Turn 90 deg. & spring back in
Contractor PU – The down valve may be stuck open.
Replace down valve cartridge.
TROUBLESHOOTING ANALYSIS