Warming-Up Operation - Hitachi ZAXIS 120-6 class 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. If
warming up the machine by relieving the hydraulic
system, continuously relieve the relief valve for 10 to
15 seconds then pause for 5 to 10 seconds.
 When the hydraulic oil temperature is 5 °C or lower,
the pump torque is restricted to protect the engine.
1. Even after engine starts, leave engine control dial (1) in
the 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 is 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:
 The engine speed will be kept to slow idle speed just after
the engine starts. When engine speed control indicator (7)
is displayed, slow idle speed will be maintained. 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.
 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
CAUTION: Do not attempt to operate the machine
when engine speed control indicator (7) is lit. The
engine speed may change after the slow idle period
and operation speed of work device may suddenly
increase, which may cause a serious accident.
OPERATING THE MACHINE
5-3
Slow Idle
2
7
1
M1P1-01-068
MDC1-01-001
M1P1-05-003
MDC1-01-355