Hardi Mercury Covamax series Operator's Instruction Manual

7 - Fault Finding1. 3SensorsFlow Sensor InspectionThe flow sensor is a “Proximity” type sensor and may be tested forcorrect operation as follows:• Switch on the power to the sprayer but do not run the pump(ie 0 bar).• Locate the Flow sensor in the fluid supply manifold at thefront of the sprayer and loosen it’s threaded retaining nut.• Rotate the spindle by hand (do not use compressed air) andwatch the in-built LED test light for a signal.If the sensor is working correctly the red LED will pulse with eachrevolution of the spindle. If the Flow sensor is found to befunctional, re-install it in the manifold taking care not to damagethe “O” ring seal (use rubber grease on re-assembly).Fluid systemFault Possible cause Suggested actionPressure increasing. Boom nozzle filters becoming blocked Clean all filters.Formation of foam. Air is being sucked into system. Check tightness/gaskets/O-rings of all fittings onsuction side.Excessive liquid agitation. Reduce agitationMake sure that returns inside tank are present.Use foam damping additive.Liquid leaks from the bottom of HARDI pump. Damaged diaphragm Replace. See “Maintenance” section of thismanual for instructions on servicing pumpsOperating unit not functioning. Blown fuse(s). Check mechanical function of micro-switches. Usecleaning/lubricating agent if the switch does notoperate freely.Check motor. 450-500 milli-Amperes max. Changemotor, if over.Wrong polarity. Brown - pos. (+). Blue - neg. (-).Section valves not closing properly. Check valve seals for obstruction and wear,overhaul if necessary (see “Maintenance” sectionof this manual for details). Check micro-switchplate position. Loosen screws holding plate a 1/2turn. Check that the micro-switches in the EFCvalve motors are shutting the motors off correctlyNo power. Wrong polarity. Check that brown is pos. (+), Blueis neg. (-).Check printed circuit board for dry solders orloose connections.Check fuses and holders for integrity and security.