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505095M 1/3/06
Table 7
R−410A Temperature (°F) − Pressure (Psig)
°F
Psig
°F
Psig
°F
Psig
°F
Psig
32
100.8
63
178.5
94
290.8
125
445.9
33
102.9
64
181.6
95
295.1
126
451.8
34
105.0
65
184.3
96
299.4
127
457.6
35
107.1
66
187.7
97
303.8
128
463.5
36
109.2
67
190.9
98
308.2
129
469.5
37
111.4
68
194.1
99
312.7
130
475.6
38
113.6
69
197.3
100
317.2
131
481.6
39
115.8
70
200.6
101
321.8
132
487.8
40
118.0
71
203.9
102
326.4
133
494.0
41
120.3
72
207.2
103
331.0
134
500.2
42
122.6
73
210.6
104
335.7
135
506.5
43
125.0
74
214.0
105
340.5
136
512.9
44
127.3
75
217.4
106
345.3
137
519.3
45
129.7
76
220.9
107
350.1
138
525.8
46
132.2
77
224.4
108
355.0
139
532.4
47
134.6
78
228.0
109
360.0
140
539.0
48
137.1
79
231.6
110
365.0
141
545.6
49
139.6
80
235.3
111
370.0
142
552.3
50
142.2
81
239.0
112
375.1
143
559.1
51
144.8
82
242.7
113
380.2
144
565.9
52
147.4
83
246.5
114
385.4
145
572.8
53
150.1
84
250.3
115
390.7
146
579.8
54
152.8
85
254.1
116
396.0
147
586.8
55
155.5
86
258.0
117
401.3
148
593.8
56
158.2
87
262.0
118
406.7
149
601.0
57
161.0
88
266.0
119
412.2
150
608.1
58
163.9
89
270.0
120
417.7
151
615.4
59
166.7
90
274.1
121
423.2
152
622.7
60
169.6
91
278.2
122
428.8
153
630.1
61
172.6
92
282.3
123
434.5
154
637.5
62
175.4
93
286.5
124
440.2
155
645.0
System Operation
The outdoor unit and indoor blower cycle on demand from
the room thermostat. When the thermostat blower switch
is in the
ON
position, the indoor blower operates continu-
ously.
High Pressure Switch
XC15 units are equipped with a high pressure switch that is
located in the liquid line to the compressor. The switch is a
SPST, manual−reset switch that is normal closed. The
switch opens at 590 psi.
Low Pressure Switch
XC15 units are equipped with a low pressure switch that is
located in the vapor line to the compressor. The switch is a
SPST, auto−reset switch that is normal closed. The switch
opens at 40 psi and closes at 90 psi.
Filter Drier
A drier is factory−installed in each XC15 unit. A replace-
ment drier is available from Lennox. Refer to Lennox Re-
pair Part Program.
System Operation Monitor (LSOM)
The diagnostic indicator detects the most common fault
conditions in the air conditioning system. When an abnor-
mal condition is detected, the module communicates the
specific condition through its ALERT and TRIP lights. The
module is capable of detecting both mechanical and elec-
trical system problems. See figure 18 for the system op-
eration monitor.
System Operation Monitor
Figure 18
.25" SPADE
CONNECTOR (4)
POWER LED
Y
DATA OUTPUT
CONNECTOR
L
R
C
ALERT LED
TRIP LED
IMPORTANT
This monitor does not provide safety protection.
The monitor is a monitoring device only and cannot
control or shut down other devices
.
LSOMLED Functions
Power LED (green)
indicates
voltage within the range of
19−28VAC is present at the system monitor power connec-
tion.
Alert LED (yellow)
communicates an abnormal system
condition through a unique Flash Code the alert LED
flashes a number of times consecutively; then pauses;
then repeats the process. This consecutive flashing corre-
lates to a particular abnormal condition.
Trip LED (red)
indicates there is a demand signal from
the thermostat but no current to the compressor is de-
tected by the module.
Refer to table 8 for the complete explanation of trouble-
shooting codes.
Resetting alert codes
Alert codes can be reset manual-
ly or automatically:
S
Manual reset: Cycle the 24VAC power to LSOM off
and on. After power up, existing code will display for
1 minute and then clear.
S
Automatic reset: After an alert is detected, the LSOM
continues to monitor the compressor and system.
When/if conditions return to normal, the alert code is
turned off automatically.
LSOML terminal connection
The L connection is used to communicate alert codes to
the room thermostat. On selected Lennox SignatureStat
t
thermostats, a blinking check" LED will display on the
room thermostat and on select White-Rodgers room ther-
mostats, an icon on the display will flash. Either will flash at
the same rate as the LSOM yellow alert LED.
