Komatsu D31EX-21, Operation & Maintenance Manual, Page: 110 / 256

EXPLANATION OF COMPONENTS
OPERATION
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PREVENTION METHOD OF ENTRY OF DUST 3
Dust may be prevented from entering the cab room by pressur-
izing the inside air to be slightly higher than the outside air.
When working in a dusty job site or when preventing dust from
entering the cab, use this function.
q
Close the windows and doors.
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Set FRESH/RECIRC selector switch (1) to FRESH.
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Set air flow selector switch (2) to LOW, MEDIUM, or HIGH.
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Set air conditioner switch (3) and cab temperature control
switch (4) to the desired positions.
Set temperature control switch (4) to the desired position.
PRECAUTION WHEN USING AIR CONDITIONER 3
CARRY OUT VENTILATION FROM TIME TO TIME WHEN USING THE COOLER
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If you smoke when the cooler is on, the smoke may start to hurt your eyes, so turn the lever to FRESH to
remove the smoke while continuing the cooling.
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When the air conditioner is used for long periods, carry out ventilation once every hour.
BE CAREFUL NOT TO MAKE THE TEMPERATURE IN THE CAB TOO LOW
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When the cooler is on, set the temperature so that it feels slightly cool when entering the cab (5 to 6°C) lower
than the outside temperature). This temperature difference is considered to be the most suitable for your
health, so always be careful to adjust the temperature properly.
DIRECTION OF VENTS WHEN COOLING
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If the temperature and humidity of the outside air is high, and the air conditioner is used for a long time with the
grill of the vents for the front window defroster open, moisture may condense on the outside of the glass and
reduce the visibility. If this happens, close the grill or change the direction of the louvers.
INSPECTION DURING OFF-SEASON 3
Even during the off-season, run the compressor at low speed for several minutes once a week to prevent the loss
of the oil film at the lubricated parts of the compressor. (Run the engine at low speed and set the temperature con-
trol lever at the central position.)
REMARK
When the ambient temperature is low, if the compressor is suddenly run at high speed, it may cause failure of the
compressor. Note that the system is set so that the compressor will not run when the cooler switch is turned on, if
the ambient temperature is less than 2 to 6.5°C.