Warming Up Operation - Hitachi ZAXIS 135US-5B Operator's Manual

Warming Up Operation

In cold weather, warm up the machine until coolant and
hydraulic oil temperature increases to the appropriate
operating temperature.
IMPORTANT:
 The appropriate hydraulic oil operating temperature
on this machine is 50 to 80 °C. Hydraulic components
may be seriously damaged if the machine is
operated with low temperature hydraulic oil. In case
warming up the machine by relieving the hydraulic
system, continuously relieve the relief valve for 10 to
15 seconds while taking a pause for 5 to 10 seconds.
 When the hydraulic temperature is 5 °C or lower, the
pump torque is restricted to protect the engine.
1. Even after the engine starts, leave engine control dial (1)
in slow idle position.
(Do not operate the machine until the needle of coolant
temperature gauge (2) starts swinging.)
2. After the needle of coolant temperature gauge (2) starts
swinging, turn engine control dial (1) to approx. medium
position.
3. Operate the boom, arm and bucket cylinders slowly to
each stroke end several times. If the machine equipped
with various attachments, operate the attachment
function slowly to allow hydraulic oil to circulate through
the system.
4. Operate the travel and swing functions slowly to allow
hydraulic oil to circulate through the systems.
5. Warming up operation ends after the above operation is
completed.
f
NOTE: Because of the engine speed control function, the
engine speed will be kept to slow idle speed for about 3 to
6 seconds right after the engine starts. When the coolant
temperature or hydraulic oil temperature is low, the time
will be longer. The engine speed will be kept to slow idle
speed even if engine control dial (1) is not set in the slow idle
position.
f
NOTE: The warm-up system automatically operates
after keeping slow idle speed, and the engine speed will
temporarily increase even if engine control dial (1) is in the
slow idle position.
d
WARNING: Do not attempt to operate the machine for
six seconds after starting the engine. The engine speed
may change after the slow idle period and operation
speed of work device may suddenly increase, which
may cause serious accident.
OPERATING THE MACHINE
5-5
Slow Idle
2
1
M1P1-01-068
MDAA-01-001EN
M1P1-05-003