Komatsu PC390LC-10 Shop Manual page 31

FOREWORD
HANDLING ELECTRIC EQUIPMENT AND HYDRAULIC
COMPONENTS
To maintain the performance of the machine over a long period, and to prevent failures or other troubles before they occur,
correct operation, maintenance and inspection, troubleshooting, and repairs must be performed. This section deals particularly
with correct repair procedures for mechatronics and is aimed at improving the quality of repairs. For this purpose, it gives
sections on "Handling electric equipment" and "Handling hydraulic equipment" (particularly gear oil and hydraulic oil).
Points to Remember When Handling Electric Equipment
1. Handling wiring harnesses and connectors.
• Wiring harnesses consist of wiring connecting one component
to another component, connectors used for connecting and
disconnecting one wire from another wire, and protectors or
tubes used for protecting the wiring.
• Compared with other electrical components fitted in boxes or
cases, wiring harnesses are more likely to be affected by the
direct effects of rain, water, heat, or vibration. Furthermore,
during inspection and repair operations, they are frequently
removed and installed again, so they are likely to suffer
deformation or damage.
• For this reason, it is necessary to be extremely careful when
handling wiring harnesses.
2. Main failures occurring in wiring harness.
A. Defective contact of connectors (defective contact between
male and female).
• Problems with defective contact are likely to occur
because the male connector is not properly inserted into
the female connector, or because one or both connectors
are deformed or the position is not correctly aligned, or
there is corrosion or oxidation of the contact surfaces.
B. Defective crimping or soldering of connectors.
• The pins of the male and female connectors are in contact
at the crimped terminal or soldered portion, but if there is
excessive force brought to bear on the wiring, the plating
at the joint will peel and cause improper connection or
breakage.
PC360/390LC-10
HANDLING ELECTRIC EQUIPMENT AND HYDRAULIC COMPONENTS
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