Komatsu WA200-8 Operation & Maintenance Manual page 225

OPERATION
2.
After preheating pilot lamp (2) goes out, turn starting
switch key (1) to START position (C).
Keep the key in starting switch (1) at position (C) to keep
running the starting motor until the engine starts.
The starting motor keeps running to start the engine.
REMARK
• Do not operate the starting motor continuously for
more than 20 seconds.
• If the engine does not start, release your hand from
the starting switch, wait for 1 minute, and then start
the engine again.
3.
After the engine starts and its speed increases, release
your hand from the key of starting switch (1).
The key returns automatically to ON position (B).
REMARK
When the engine is started, white smoke may come out of
the exhaust pipe. It is fine water particles which are pro-
duced from moisture or water vapor and which seem
white, thus it does not indicate a problem.
The smell of the exhaust gas is different from that of the
conventional diesel machine because of the exhaust gas
filtering function.
REMARK
Urea SCR system has the function of heating and keeping itself warm to prevent freezing of DEF.
If DEF is frozen, DEF system is automatically heated and thawed after the engine is started. The devices
do not operate until DEF is thawed and supplied, but this does not indicate any abnormality.
When the ambient temperature decreases to a level where DEF may freeze while the machine is in opera-
tion, DEF system is warmed automatically to prevent freezing. When the ambient temperature decreases to
a level where freezing of DEF is not preventable, the devices stop automatically, but this does not indicate
any abnormality.
If DEF freezes, thawing operation is performed automatically. Never heat DEF. Harmful ammonia gas may
be generated.
TURBOCHARGER PROTECTION FUNCTION
The turbo protect function protects the turbocharger by keeping the engine speed at approximately 1000 rpm or
less immediately after the engine is started.
When the turbo protect function and automatic warm-up function operate at the same time, the turbo protect
function is given priority.
• While the turbo protect function is operating, increase of the engine speed is restricted even if the accelera-
tor pedal is depressed.
• When the turbo protect function is canceled, the engine speed becomes the speed according to the de-
pressed level of the accelerator pedal.
• The relationship between the actuating time of the turbo protect function and the temperature of the engine
coolant is as shown in the table.
Coolant temperature
( °C)
Min. 10
10 to -30
Turbo protect time (sec.)
0
Variable between 0 and 20
MACHINE OPERATIONS AND CONTROLS
3-161