Troubleshooting With Gauge Pressure - Komatsu PC200-8M0 Shop Manual

100 Air conditioner

Troubleshooting with gauge pressure

Troubleshooting with gauge pressure
Perform troubleshooting according to the high and
low gauge pressures of the cooling cycle. For de-
tails, see "Connection of service tool".
a The gauge pressure varies largely with the
weather condition and operating condition of the
machine. Check the gauge pressure under the
pressure measurement conditions.
q High-pressure line pressure is too high: Above
approx. 2.5 MPa {25 kg/cm
High-pressure line pressure is too low: Below
q
approx. 1 MPa {10 kg/cm
q Low-pressure line pressure is too high: Above
approx. 0.3 MPa {3 kg/cm
q Low-pressure line pressure is too low: Below ap-
prox. 0.05 MPa {0.5 kg/cm
a Dual pressure switch turns "OFF" to protect the
air conditioner circuit if the pressure of the
high-pressure or low-pressure line is abnormal.
PC200, 200LC, 220, 220LC-8M0
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<Measurement condition for pressure>
Item
Ambient temperature
Engine speed
Air conditioner switch
Fan switch
Set temperature
q Dual pressure switch
a The swiths is normally "ON", and becomes
"OFF" when it detects abnormal pressure for
compressor operation.
LA: 0.20 MPa {2 kg/cm
LB: 0.02 MPa {0.2 kg/cm
HA: 3.14 MPa {32 kg/cm
HB: 0.59 MPa {6 kg/cm
SEN06151-00
Condition value
25 to 50 °C
1,500 rpm
ON
HI
Full cool
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80-100
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