Diagnostic Charts - Carrier 40GXC Service Manual

DIAGNOSTIC CHARTS

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