McHale 991BE - Troubleshooting Control and Hydraulic Systems; Control Box and Hydraulic System Faults

McHale 991B Round Bale Wrapper
83
15.1.4 Cut & hold
15.1.5 Control box
15.1.6 Hydraulics
Symptom Reason Solution
Cut & hold not catching
plastic film
Positioned incorrectly Check position
Table not stopping in the
correct tip off position
Check and adjust magnets
if necessary
Cut & hold not opening Pressure low on
accumulator
Prime accumulator
Cut & hold not closing Pressure high on
accumulator
Release pressure from
accumulator
Cut & hold leaks back
slowly
Seals weak in the gearbox Replace seals
Loose hydraulic fitting on
gearbox
Tighten hydraulic fitting
Cut & hold and tip-up
cycles very slow
Tractor pressure too low Ensure tractor has 150 bar
pressure
Faulty pressure switch
(electronic machines)
Replace pressure switch
Relief valve set too low Set to 150 bar pressure
Symptom Reason Solution
Control box not counting Sensor damaged Locate and replace
Magnet broken Locate and replace
Sensor - magnet clearance Adjust sensor approx. 10-
15 mm from magnet.
Faulty control box Replace control box
“LOW BATT” appears on
the control box
Supply voltage too low Check battery and
charging system
Only half the number of
actual rotations is
displayed on the control
box
One set of magnets
missing
Replace the missing set of
magnets
Control box will not switch
to “auto” setting
Loom not connected to the
box
Connect loom
Symptom Reason Solution
Hydraulics under pressure
when the wrapper is idle
Valve set to closed centre
on open centre system
Change the setting