Southworth APCU Series, Operating And Maintenance Manual

Page: 31 / 46

APCU Owner’s Manual 31
Symptom Possible Cause Remedy
The tilt mechanism raises slowly. The counter-balance valve in this circuit
may be plugged.
Release the pressure from the system and clean the
valve.
The tilt mechanism does not lower.
Warning! Before working under any
raised parts of the unit, support the
body of the unit using a set of strong
supports.
The “down” side of the control valve for
this part of the system may not be work-
ing.
The “down” side of the valve must be energized and
fully open. Check the solenoid on the “down” side of
the valve with a voltmeter. Check for a problem with
the wiring to the control valve. The valve must be
clean and free to operate. Release the pressure from
the system and clean the valve. (See the section on
“Inspecting and Cleaning a Control Valve”.)
When the load enclosure is lowered,
the center or rear touches the floor
before the front edge (load edge).
The floor is not flat. Insert shims above the low spots in the floor. The
base frame of the machine must be flat and level.
The pump motor continues to run
after the front edge (load edge) of
the load enclosure touches the floor.
The proximity switch for the “Tilt Down”
function may be out of adjustment.
Adjust the position of the target for this switch.
The “Tilt Down” part of the cycle
begins prematurely.
The tilt frame may be hitting the stop pads
at the upper limit of travel too hard.
Adjust the position of the target for the “Tilt Up”
proximity switch.
The dump mechanism will not raise. The up-proximity switch for the dump lift
function may be out of adjustment.
Check the adjustment of the switch. (See the section
on “Adjustment and Alignment”.)
The “up” side of the control valve for this
function may not be working
The “down” side of the valve must be energized and
fully open. Check the solenoid on the “down” side of
the valve with a voltmeter. Check for a problem with
the wiring to the control valve. The valve must be
clean and free to operate. Release the pressure from
the system and clean the valve. (See the section on
“Inspecting and Cleaning a Control Valve”.)
The dump mechanism raises slowly. The counter-balance valve in this circuit
may be out of adjustment.
Release the pressure from the system and clean the
valve.
The pump motor continues to run
after the load enclosure has reached
the upper limit of the dump travel.
The “Dump Up” proximity switch may be
out of adjustment.
Check the adjustment of the switch. (See the section
of “Adjustment and Alignment”.)
The dump mechanism does not
lower.
The “down” side of the control valve for
this part of the system may not be work-
ing.
The “down” side of the valve must be energized and
fully open. Check the solenoid on the “down” side of
the valve with a voltmeter. Check for a problem with
the wiring to the control valve. The valve must be
clean and free to operate. Release the pressure from
the system and clean the valve. (See the section on
“Inspecting and Cleaning a Control Valve”.)
The dump mechanism lowers slowly. The counter-balance valve in the circuit
may be plugged.
Release the pressure from the system and clean the
valve.
At the end of the cycle, the load en-
closure drops onto the base frame.
The proximity switch for the “Dump Down”
function may be set too high. When the
motor is shut off, this allows the load
enclosure to drop.
Check the adjustment of the switch. (See the section
on “Adjustment and Alignment”.)