Komatsu H75051, Operation & Maintenance Manual

Page: 242 / 440

START IN COLD WEATHER
k k
WARNING
• Start the engine only while sitting on the operator's seat.
• Do not attempt to start the engine by short-circuiting the engine starting circuit.
Doing so may cause a fire or serious personal injury or death.
• Check that there is no person or obstacle in the area around the machine, then sound the horn and
start the engine.
• Exhaust gas is toxic.
When starting the engine in confined spaces, be particularly careful to ensure good ventilation.
NOTICE
• Do not accelerate the engine abruptly until it is
warmed up.
• This machine is equipped with the automatic warm-up
function to heat the coolant more quickly and the tur-
bo protect function to protect the turbocharger.
In cold weather startup, the engine speed may not
change for several seconds immediately after the
startup even if accelerator pedal (3) is depressed.
• If the machine is left for a long time with engine run-
ning at idle, inside of KCCV and blowby piping may be
frozen and blocked.
To prevent freeze, stop the engine or, if it is necessary
to run the engine at idle, apply the load from time to
time.
When the engine is started after it has been left at temperature
of approximately -20 °C for more than a half day, it takes time
to attain perfect combustion.
Operate the starting switch according to the following proce-
dure.
1.
Turn the key in starting switch (1) to ON position (B).
When the ambient temperature is low, preheating pilot
lamp (2) lights up and automatic preheating is performed.
Keep the starting switch key (1) at ON position until pre-
heating pilot lamp (2) goes out.
The time that preheating pilot lamp (2) stays lit depends on
the ambient temperature as shown in the table.
Ambient temperature ( °C) Lighting time (sec.)
-1 to -15 0 to 30
Below -15 30
REMARK
Usually, the engine is preheated sufficiently by the automatic preheating. If it is needed to extend the pre-
heating time, turn the key in starting switch (1) to position (D) and hold it in the position.
Do not preheat the engine more than 30 seconds, however.
MACHINE OPERATIONS AND CONTROLS OPERATION
3-176