Carrier 38GXC - Manual (Page 17)

17
DIAGNOSTIC CHARTS
Weigh in charge.
Yes
No
Replace thermistor
Connect low side gauge at
suction service valve.
Measure discharge temp.*
Indoor fan motor
running?
Check motor
Chart
No
Yes
No
Check for leaks.
Reclaim charge and fix
leak.
Yes
Clean indoor coil and
filter. Problem fixed?
No
Yes
Problem solved
Check indoor coil
temperature thermistor .
Chart 4, ok?
Replace indoor board. Weigh in charge.
Yes
No
Replace thermistor
Connect low side gauge at
suction service valve.
Measure discharge temp.*
Indoor fan motor
running?
Check motor
Chart
No
Yes
No
Check for leaks.
Reclaim charge and fix
leak.
Yes
Clean indoor coil and
filter. Problem fixed?
No
Yes
Problem solved
Check indoor coil
temperature thermistor .
Chart 4, ok?
Replace indoor board.
Yes
No
Replace thermistor
Connect low side gauge at
suction service valve.
Measure discharge temp.*
Indoor fan motor
running?
Check motor
Chart
No
Yes
No
Check for leaks.
Reclaim charge and fix
leak.
Yes
Clean indoor coil and
filter. Problem fixed?
No
Yes
Problem solved
Check indoor coil
temperature thermistor .
Chart 4, ok?
Replace indoor board.
A09360
Fig. 28 – Indoor Freeze Protection
Check compressor
discharge line thermistor .
Ok?
Suction and discharge
pressures low?
Check for leaks.
Reclaim charge and fix
leak.
Weigh in charge.
Check for blocked
capillary tube or a restriction
in liquid line
Ok
Yes
No
Yes
No
Yes
Connect low side gauge at
suction service valve.
Measure discharge temp.*
No
Replace thermistor
Yes
High head, low suction?
Restriction in refrigeration
circuit.
Yes
Check compressor
discharge line thermistor .
Ok?
Suction and discharge
pressures low?
Check for leaks.
Reclaim charge and fix
leak.
Weigh in charge.
Check for blocked
capillary tube or a restriction
in liquid line
Ok
Yes
No
Yes
No
Yes
Connect low side gauge at
suction service valve.
Measure discharge temp.*
No
Replace thermistor
Yes
High head, low suction?
Restriction in refrigeration
circuit.
Yes
A09361
Fig. 29 – High Compressor Discharge Temperature
38/
40GX
C
(Q
)