Lennox LNINVE052 Service Manual page 63

Drop
malfunction
32 U3
of DC busbar
voltage
Low voltage
33 protection of PL
DC bus bar
Limit/
decrease
frequency due
34 EU
to module
temperature
protection
4-way valve is
35 U7
abnormal
60
Flash
20 times
□ ■ ■
every 3s
Flash
21 times
□ ■ ■
every 3s
■ ■ ■
■ □ ☆
During cooling
and drying
operation,
compressor and
Power voltage
outdoor fan stop
is unstable, big
■
while indoor
fluctuation.
fan operates.
During heating
operation, all
loads stop.
During cooling
The voltage at
and drying
positions L and N
operation,
on wiring board
compressor and
(XT) is lower than
outdoor fan stop
150 VAC
□
while indoor
Hardware
fan operates.
malfunction of
During heating
outdoor unit's
operation, all
main board;
loads stop.
Radiating grease
on IPM module
All loads
of outdoor unit's
operates
main board is not
normally, while
enough; screws
operation
haven't been
☆
frequency of
fixed tightly;
compressor
decreases.
Hardware
malfunction of
outdoor unit's
main board;
Power voltage
is lower than
AC175V
Wiring terminal
This malfunction
4V is loose or
occurs under
broken
heating
□
operation: all
loads stop.
Hardware
malfunction of
outdoor unit's
main board;
Service Manual
1. Check
whether power
supply network is
abnormal;
1. Check
whether power
supply network is
abnormal;
2. Replace
outdoor unit's
main board AP1;
1. After the
system is de-
energized for
20min and
discharge,
check whether
radiating grease
on IPM Module
of outdoor
control board
AP1 is enough
and whether the
radiating is fixed
tightly;
2. Replace
outdoor unit's
main board AP1;
2. After de-
energization,
insert OVC-
COMP tightly or
replace wiring
3. Replace
outdoor unit's
main board AP1;
Installation and Maintenance