Common trouble and elimination
C-18
Common trouble and troubleshooting of air conditioner system
The remedy and trouble analysis under abnormal pressure
No. Pressure
Description
Analysis
Remedy
1
The high and low
pressure is lower
than normal.
There is bubble in the
inspection glass
；
the
cold air in the bus
insufficient
；
high
pressure pipe a little bit
warm and the low
pressure pipe a little bit
cold, the temperature
difference is not too
much
；
The refrigerant
filling is not
enough and the
system is
leaking
Check the
system for the
leakage and find
out the leaking
point
And make the
maintenance
Fill in refrigerant
The high and low
pressure are higher
Than normal
The refrigerant is
too much
Drain some part
of the refrigerant
or refrigerant oil
2
The high and low
pressure are much
lower than
normal .
No liquid flow seen
from the inspection
glass;
Almost no refrigeration
Almost no temperature
difference between high
and low pressure pipe
Air conditioner
system has
serious leakage
Check the
system and find
out the leakage
and fill the
enough
refrigerant
3
The low pressure
is nearly to zero or
even the negative
value;
The high pressure
is lower than the
normal value
No refrigerate in the
system
The front or the rear
part of the expansion
valve has fog
expansion valve
blocked
；
expansion valve
temperature
sensor damaged
or packing error
Changed the
expanding valve
Change the
expanding valve
temperature
sensor
Make good
package for the
expanding valve
The high pressure
and the low
pressure are
abnormal;
The pressures
are higher than the
normal values
The temperature of the
sucking pipe is lower
than the normal value
and the frosting
appeared
expansion valve
opened too much
Change the
expanding valve
Readjust the
expanding valve
The high pressure
is higher than the
normal value and
the low pressure is
lower than normal
The surface for the air
suction pipe of the
compressor has frost or
condensate
Expanding valve
damaged
Change the
expanding valve
Summary of Contents for XMQ6120C series
Page 36: ...Technical parameter and complete vehicle description 0 K 1 Lock1 Lock 2 Lock 3 ...
Page 133: ...Appendix A 4 Air braking schematic diagram ...
Page 134: ...Appendix A 4 Electric schematic diagram of the complete vehicle 1 ...
Page 135: ...Appendix A 5 Electric schematic diagram of the complete vehicle 2 ...
Page 136: ...Appendix A 5 Electric schematic diagram of the complete vehicle 3 ...
Page 137: ...Appendix A 5 Electric schematic diagram of the complete vehicle 4 ...
