Autoquip DOUBLE PANTOGRAPH LIFT - Manual (Page 67)

67
DANGER!
To avoid personal injury, NEVER go under the lift platform until the load is
removed and the scissors mechanism is securely blocked in the open position.
See "Lift Blocking Instructions" section.
PROBLEM POSSIBLE CAUSE AND SOLUTION
Lift will 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 screen may be clogged, starving the
pump. Remove and clean the screen. 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. Check the solenoid wiring.
• The "Down" valve stem may be bent causing the
valve to stick open. Replace the down solenoid
valve.
• 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.
TROUBLESHOOTING ANALYSIS