Lennox XC21 Installation Instructions Manual page 38

Outdoor A175 Main
icomfort icomfort
Control LEDs
Toucht Toucht
Thermostat Thermostat
DS15 DS13
Display Display
Yellow Red
3 Flashes Moderate
then OFF Alert Code
Pause 403
4 Flashes
Critical Alert
then
OFF
Code 404
Pause.
5 Flashes
Critical Alert
then OFF
Code 405
Pause
6 Flashes
Critical Alert
then
OFF
Code 406
Pause
7 Flashes
Critical Alert
then
OFF
Code 407
Pause
8 Flashes
Critical Alert
then
OFF
Code 408
Pause
9 Flashes Moderate/
then OFF Critical Alert
Pause Code 409
Fast simultaneous flashing of
DS11, DS13, DS14 and DS15
506518−01
Possible Possible
Condition Condition
Cause(s) Cause(s)
Compressor is
Short Cycling running less than
three minutes.
Compressor has
a locked out due
to run capacitor
short, bearings
Locked Rotor
are seized, ex-
cessive liquid re-
frigerant.
Compressor has
an open circuit
due to power dis-
Open Circuit
connection, fuse
is open or other
similar conditions.
Current not
Open Start
sensed by Start
Circuit
transformer.
Current not
Open Run
sensed by run
Circuit
transformer.
Welded Compressor
Contactor always runs
Secondary 24VAC is below
Low Voltage 18VAC.
OEM Mode Factory Test Mode.
Page 38
Solution Solution
1
Thermostat demand signal is intermittent.
2
Time delay relay or A175 Main Control is
defective.
3
If high pressure switch is present, see
Flash Code 2 information.
1
Run capacitor has failed.
2
Low line voltage (contact utility if voltage
at disconnect is low).
S
Check wiring connections
3
Excessive liquid refrigerant in the com-
pressor.
4
Compressor bearings are seized.
1
Outdoor unit power disconnect is open.
2
Unit circuit breaker or fuse(s) is open.
3
Unit contactor has failed to close.
S
Check compressor contactor wiring
and connectors
S
Check for compressor contactor fail-
ure (burned, pitted or open)
S
Check wiring and connectors between
supply and compressor
S
Check for low pilot voltage at com-
pressor contactor coil
4
High pressure switch is open and requires
manual reset.
5
Open circuit in compressor supply wiring
or connections.
6
Unusually long compressor protector reset
time due to extreme ambient temperature.
7
Compressor windings are damaged.
S
Check compressor motor winding re-
sistance
1
Run capacitor has failed.
2
Open circuit in compressor start wiring or
connections.
S
Check wiring and connectors between
supply and the compressor S terminal
3
Compressor start winding is damaged.
S
Check compressor motor winding re-
sistance
1
Open circuit in compressor start wiring or
connections.
S
Check wiring and connectors between
supply and the compressor R terminal
2
Compressor start winding is damaged.
S
Check compressor motor winding re-
sistance
1
Compressor contactor failed to open.
2
Thermostat demand signal not connected
to module.
1
Control circuit transformer is overloaded.
2
Low line voltage (contact utility if voltage
at disconnect is low).
S
Check wiring connections
Clearing Status Clearing Status
Clears after four
consecutive normal
compressor run cycles,
or after power reset.
Clears after power reset
or four normal
compressor cycles.
Clears after one normal
compressor run cycle or
power reset.
Clears when amperage
is detected in RUN and
START sensors, or after
power reset.
Clears when amperage
is detected in RUN and
START sensors, or after
power reset.
Clears after one normal
compressor run cycle or
after power reset.
Clears after voltage is
higher than 20VAC for
two seconds, or after
power reset.