Carrier 40MPHA Service Manual page 23

ERROR DIAGNOSIS AND TROUBLESHOOTING WITHOUT ERROR CODE (continued)
Field Maintenance
Possible causes
Heavy load condition
of trouble
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 (outdoor) 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
Test method / remedy
Table 14 — Field Maintenance
Loosen hold down bolts and/or screws
☆
☆
☆
Check heat load Tighten bolts or screws
Others
Shipping plates remain attached Poor choices of capacity
☆
Choose AC of larger capacity or add
Remove them
the number of units
Contact of piping with other piping or
external plate
☆
☆
Fix piping as not to touch each
other or external pipe