ARAG Electriccontrol unit for crop-spraing application 871 - Manual (Page 27)

27
6.3 Troubleshooting
FAULT CAUSE REMEDY
Working pressure cannot be
achieved by operation of switch
on main valve control device
Main valve motor malfunctioning
• Check electric connection.
• Have gearmotor inspected at the nearest
Service Centre.
Inlet and outlet tubes not connected
correctly • Check delivery and outlet tube connec-
tions.
Maximum pressure valve fully
loosened
• Adjust maximum pressure valve.
Self-cleaning filter drain fully open • Tighten knob of self-cleaning filter.
Delivery filter clogged • Clean delivery filter cartridge.
Suction filter clogged • Clean suction filter cartridge.
Insufficient liquid delivery to control
unit
• Check pump rate.
• Increase pump RPM.
• Check for open branches or drain outlets
upstream of control unit.
Proportional valve fully open
• Operate pressure control switch to close
proportional valve.
Pressure cannot be reduced
by operation of switch on main
valve control device
Proportional valve motor not working
• Check electric connection.
• Have gearmotor inspected at the nearest
Service Centre.
Proportional valve drain passage
clogged
• Clean drain passage.
A hydraulic agitator is connected to
drain passage of proportional valve • Remove hydraulic agitator and leave hole
open.
Drain tube of proportional valve
undersized
• Change drain tube.
Proportional valve flow rate lower
than desired rate setting
• Change proportional valve.
Liquid coming out of section val-
ves when main valve is closed
Drain passage of main valve ob-
structed
• Clean drain passage.
A hydraulic agitator is connected to
drain passage of proportional valve • Remove hydraulic agitator and leave hole
open.
Drain tube of proportional valve
undersized
• Change drain tube.
Main valve plug gasket worn out
• Gasket needs replacing; bring complete
unit to the nearest Service Centre.
Chemical residue on gaskets and
seat of main valve hose tail
• Clean parts with suitable detergent as indi-
cated in Cap. 6 - Maintenance / Diagnostics
/ Repairs.
CONTINUES