Carrier 40MPHA Service Manual page 22

ERROR DIAGNOSIS AND TROUBLESHOOTING WITHOUT ERROR CODE (continued)
Field Maintenance
Possible causes Compressor Refrigerant Restricted
liquid line Dry air filter
of trouble stuck Shortage
Unit will not start
Compressor will not
start however the
☆
fan runs
Compressor and
condenser (outdoor)
fan will not start
Evaporator (indoor)
fan will not start
Condenser (out-
door) fan will not
start
Unit runs but
☆
shortly stops
Compress or short
cycles due to
☆
overload
High discharge
pressure
Low discharge
☆
pressure
High suction
pressure
Low suction
☆
pressure
Unit runs
continuously but
☆
insufficient cooling
Too cool
Compressor is noisy
Horizontal louver
can not revolve
Replace the
Test method / Replace the
Leak test restricted
remedy compressor
Table 13 — Field Maintenance
Insufficient
Dirty air
Refrigerant
evaporator through
overcharge
coil evaporator
coil
☆
☆ ☆ ☆ ☆
☆ ☆ ☆ ☆
Change
Clean or charged
Clean coil Check fan
replace refrigerant
part
volume
Refrigerant Circuit
Air or non-
Dirty or Short
condensible High temp.
partially cycling of
gas in condensing
blocked condensing
refrigerant medium
condenser air
cycle
☆ ☆
☆ ☆
☆ ☆ ☆ ☆ ☆
☆
☆ ☆ ☆
☆
Clean Purge, Remove
Remove
condenser evacuate obstruction
obstruction
or remove and in air or
to air flow
obstacle recharge water flow
Broken
Insufficient Expansion
compressor Insufficient
condensing valve
internal compressor
medium obstructed tube closed
parts
☆
☆
☆
☆
☆
☆
Remove
Test
obstruction Replace Replace
compressor
in air or compressor valve
efficiency
water flow
Expansion Leaking
Power
valve or power
installation
capillary element on
of feeler
expansion
bulb
completely valve
☆ ☆
☆
☆ ☆
Replace Replace Fix feeler
valve valve bulb