Trane CGCN Installation Operation & Maintenance page 61

SYMPTOM Cooling
D The X
compressor
X
does not start
X
because the
maximum
X
pressure
switch
has tripped
X
X
E The X
compressor
X
does not start
because the
minimum
X
pressure
X
switch
has tripped
X
X
X
F The fans do X
not
start X
X
X
X
G Lack of gas X
I Frost in X
liquid
pipe
downstream
from a filter
L The unit X
works
X
continuously
without ever
X
stopping
X
X
M The unit X
works X
regularly but
with
an insufficient
capacity
Heating Who can take
corrective
action
X S
X S
U
S
X U
X S
X S
X S
X S
X S
X U
U
S
X S
X S
X S
X S
X S
X S
X S
X S
X S
X
S
X S
X S
X S
X U
X S
X S
X S
X S
X S
Probable cause
Pressure switch out of order
Overcharge of refrigerant
Finned coil clogged, air flow rate is
too low
Fan not working
Water circulation pump blocked
Water circulation pump defective
Presence of non-condensable
gases in the refrigerating circuit
Refrigerant filter clogged
Pressure switch out of order
Unit completely download
Finned coil clogged, air flow rate is
too low
Water circulation pump blocked
Water circulation pump blocked
defective
Presence of frost on evaporator
coil
Evaporator fan not working
Refrigerant filter clogged
Expansion device that is not
working properly
The presence of moisture in the
refrigerant circuit
Fan contactor de-energized
Lack of output voltage from the
control fan speed
Thermal protection inside the fan
Fan motor faulty
Loose electrical connections
Loss in the refrigerant circuit
The liquid filter is clogged
Lack of refrigerant gas
Incorrect tuning of the operating
thermostat
Excessive thermal load
Compressor does not give the
thermal output
The liquid filter is clogged
Low refrigerant charge
4-way reversing valve defective
Possible remedy
Check and replace
Download the excess gas
Remove dirt from the coil and
obstructions to the airflow.
See point F
Unlock the pump
Check the pump and replace if
necessary.
Prime the circuit after it has been
downloaded and put under vacuum
Check and replace
Check and replace
See point G
Remove dirt from the coil
Unlock the pump
Check the pump and replace if
necessary.
See point O
See point F
Check and replace
Check and if necessary replace
Replace the filter and dry eventually and
recharge
Check the voltage across the coil of the
contactor and the continuity of the coil
Check the contacts, replace if necessary
Check the condition of the fan and the
air temperature during operation of the
unit.
Check and replace
Check and secure
Check the cooling circuit using a
leak detector after pressuring the
circuit to approximately 4 bars.
Repair, evacuate and refill.
Replace the filter
See item G.
Check the setting
Reduce the thermal load
Check, change or revise
Replace
See point G
Check the power supply and the coils of
the valve and replace the valve