Lennox XP21 Series Installation Instructions Manual page 47

Heat Pump Control
icomfort icomfort
LEDs
Touch Touch
Thermostat Thermostat
DS15 DS13
Display Display
Yellow Red
4 flashes Critical Alert
Off
then pause Code 404
5 flashes Critical Alert
Off
then pause Code 405
6 flashes Critical Alert
Off
then pause Code 406
7 flashes Critical Alert
Off
then pause Code 407
8 flashes Critical Alert
Off
then pause Code 408
Moderate/
9 flashes
Critical Alert
Off
then pause
Code 409
Fast simultaneous flashing of DS11,
DS13, DS14 and DS15
1. Pause duration is two (2) seconds.
2. Fast flash duration is 1/2 second. Slow flash duration is one (1) second.
3. Initially a moderate status is displayed and is escalated to critical if alarm exists for more than 10 minutes.
® ®
Possible Possible
Condition Condition
Cause(s) Cause(s)
Compressor has
a locked out due
to run capacitor
Locked rotor short, bearings
are seized,
excessive liquid
refrigerant.
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 low 24VAC is below
3
voltage 18VAC.
OEM Mode Factory test mode.
Solution Solution
1
Run capacitor has failed.
2
Low line voltage (contact utility if voltage at discon-
nect is low).
S
Check wiring connections
3
Excessive liquid refrigerant in the compressor.
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 failure
(burned, pitted or open)
S
Check wiring and connectors between supply
and compressor
S
Check for low pilot voltage at compressor
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 resistance
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 resistance
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 resistance
1
Compressor contactor failed to open.
2
Thermostat demand signal not connected to mod-
ule.
1
Control circuit transformer is overloaded.
2
Low line voltage (contact utility if voltage at discon-
nect is low).
S
Check wiring connections
Page 47
Clearing Status Clearing Status
Clears after
power reset or
four normal
compressor
cycles.
Clears after one
normal com-
pressor run
cycle or power
reset.
Clears when
amperage is de-
tected in RUN
and START
sensors, or after
power reset.
Clears when
amperage is de-
tected in RUN
and START
sensors, or after
power reset.
Clears after one
normal com-
pressor run
cycle or after
power reset.
Clears after volt-
age is higher
than 20VAC for
two seconds, or
after power re-
set.
XP21 SERIES