System Operation; Maintenance - Lennox Elite XC16 Installation Instructions Manual

°F Psig °F Psig
32 100.8 48 137.1
33 102.9 49 139.6
34 105.0 50 142.2
35 107.1 51 144.8
36 109.2 52 147.4
37 111.4 53 150.1
38 113.6 54 152.8
39 115.8 55 155.5
40 118.0 56 158.2
41 120.3 57 161.0
42 122.6 58 163.9
43 125.0 59 166.7
44 127.3 60 169.6
45 129.7 61 172.6
46 132.2 62 175.4
47 134.6

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
continuously.
TWO−STAGE COMPRESSOR
The two−stage scroll compressor operates much like the
standard scroll compressor. The two−stage compressor
steps between low capacity and high capacity as required
to meet cooling demand. The steps occur when gas is
bypassed through a vent port in the first suction pocket.
This bypassing of gas allows the compressor to operate at
low capacity if thermostat demand allows, creating a more
cost effective and efficient compressor.
Full capacity is achieved by blocking the vent port with a
slider ring. The slider ring (vent port cover) is controlled by
a 24VDC internal solenoid in the open position allowing low
capacity. When energized the internal solenoid closes the
slider ring, blocking the vent port and bringing the
compressor to full capacity. Stepping can occur during a
single thermostat demand as the motor runs continuously
while the compressor steps from low to full capacity.
FILTER DRIER
A filter drier is factory−installed in each XC16 unit to ensure
a clean, moisture−free system. Replacement driers are
available (refer to Lennox Repair Part Program).
HIGH PRESSURE SWITCH
XC16 units are equipped with a high pressure switch that is
located in the liquid line of the compressor. The switch
(SPST, manual reset, normally closed) removes power
from the compressor when liquid pressure rises above
factory setting at 590 + 10 psi.
506101−01 07/09
Table 3. HFC−410A Temperature (°F) − Pressure (Psig)
°F Psig °F Psig
63 178.5 79 231.6
64 181.6 80 235.3
65 184.3 81 239.0
66 187.7 82 242.7
67 190.9 83 246.5
68 194.1 84 250.3
69 197.3 85 254.1
70 200.6 86 258.0
71 203.9 87 262.0
72 207.2 88 266.0
73 210.6 89 270.0
74 214.0 90 274.1
75 217.4 91 278.2
76 220.9 92 282.3
77 224.4 93 286.5
78 228.0
°F Psig °F
94 290.8 110
95 295.1 111
96 299.4 112
97 303.8 113
98 308.2 114
99 312.7 115
100 317.2 116
101 321.8 117
102 326.4 118
103 331.0 119
104 335.7 120
105 340.5 121
106 345.3 122
107 350.1 123
108 355.0 124
109 360.0
LOW PRESSURE SWITCH
XC16 units are also equipped with a low pressure switch
that is located in the vapor line of the compressor. The
switch (SPST, auto−reset, normally closed) removes
power from the compressor when vapor line pressure
drops below factory setting at 40 + 5 psi.

Maintenance

Installation and service must be performed by a licensed
professional installer (or equivalent) or a service agency.
At the beginning of each cooling season, the system
should be checked as follows:
Electric shock hazard. Can cause
injury or death. Before attempting to
perform any service or maintenance,
turn the electrical power to unit OFF at
disconnect switch(es). Unit may have
multiple power supplies.
OUTDOOR UNIT
1. Clean and inspect outdoor coil (may be flushed with a
water hose). Ensure power is off before cleaning.
2. Outdoor unit fan motor is pre−lubricated and sealed.
No further lubrication is needed.
3. Visually inspect all connecting lines, joints and coils for
evidence of oil leaks.
4. Check all wiring for loose connections.
5. Check for correct voltage at unit (unit operating).
6. Check amp draw on outdoor fan motor.
Unit Nameplate: _________ Actual: __________
7. Inspect drain holes in coil compartment base and
clean if necessary.
Page 20
Psig °F Psig °F
365.0 141
125 445.9
370.0 126 451.8 142
375.1 127 457.6 143
380.2 128 463.5 144
385.4 129 469.5 145
390.7 130 475.6 146
396.0 131 481.6 147
401.3 132 487.8 148
406.7 133 494.0 149
412.2 134 500.2 150
417.7 135 506.5 151
423.2 136 512.9 152
428.8 137 519.3 153
434.5 138 525.8 154
440.2 139 532.4 155
140 539.0
WARNING
Psig
545.6
552.3
559.1
565.9
572.8
579.8
586.8
593.8
601.0
608.1
615.4
622.7
630.1
637.5
645.0