Lennox LNINVE052 Service Manual page 64

Service Manual
Zero-crossing
36 malfunction of U9
outdoor unit
Limit/
decrease
37 frequency FH
due to freeze
protection
Outdoor DC
38 fan motor L3
malfunction
Installation and Maintenance
During cooling
and drying
operation,
compressor and
outdoor fan stop
■ ■ ☆ □
while indoor
fan operates.
During heating
operation, all
loads stop.
All loads
operates
normally, while
operation
■ ■ ■ □
frequency of
compressor
decreases.
Outdoor DC
fan motor
malfunction lead
to compressor
stop operation
Hardware 1. Replace
malfunction of outdoor unit's
outdoor unit's main board
main board; AP1;
1. Check
whether indoor
unit's horizontal
Poor air return louver can
of indoor unit or close normally
speed of fan is → replace
too low indoor unit's
main board →
replace indoor
unit's motor;
DC fan motor
malfunction or
system blocked
or the connector
loosed
61