Tadano TR-800XXL4, Service Manual

Page: 214 / 402

K - 2
K - 2
Air Conditioner
31 W701-0220E
A/C system
trouble
phenomenon
Status explanation
of A/C system
pressure
Phenomenon explanation to
consider other factors
Diagnosis result (phenomenon of
principal cause)
Possible cause
Measures (specific
part name and
repair method)
----------------
Evaporator is frosting. Thermistor
is not cold. If louver blowing
temperature gets cold enough,
compressor will be OFF tentatively. Installation position failure of
thermo therms sensor
(thermistor and mechanical
thermo capillary).
Check that thermo
therms sensor is in
proper position.
Move it to proper
position in case of
NG.
----------------
Blowing air volume changes
gradually. When A/C is OFF, and
blower is ON, much water is
drained from drain hose.
Evaporator is frosting. Thermistor
is cold. If louver blowing
temperature gets cold enough,
compressor will not be OFF.
Thermistor or thermo amp.
failure (will not turn OFF).
Check thermo
system wiring, or
replace parts.
----------------
Gas leakage from
evaporator case.
Seal with repair
tape or packing
agent.
----------------
Air volume is small from the
beginning.
Evaporator frost formation.
Gas leakage from joint of
heater unit and evaporator
unit.
Affix packing
again.
Insufficient
cooling. (Normal
cooling at
beginning, and
gradually reduce
cooling later.)
---------------- Air volume does not decrease. Freezing of TXV Water intrusion in circuit.
Deflate from circuit
and fill refrigerant.
------------------------------------
Outside air intrusions to
inside, though inside
circulation. Adjust inside and
outside air switch
dumper.
-------------------------------------
Warmed with heater. (Water
valve adjustment failure or
leakage, and air mix dumper
does not close completely.)
Check and adjust
water valve and air
mix dumper.
Blowing temperature is high and it
does not get cold (refrigeration
circuit is normal).
-------------------------------------
Thermostat operating
temperature failure.
Check thermostat.
(Check mechanical
thermo, thermistor,
thermo amp., and
thermo VR.)
------------------------------------- Blocking of evaporator fin.
Wash or replace
evaporator.
Blower motor revolution is
slow. Check and replace
blower motor.
Insufficient
cooling.
Normal
Air volume is few and does not get
cold, though blowing temperature is
cold.
-------------------------------------
Blocking of blower
inhalation vent.
Check and repair.