103142-YIM-A-1204
8
Unitary Products Group
Comfort Alert
TM
Diagnostics —
The Comfort Alert
TM
diagnostics
module facilitates troubleshooting heat pump and air conditioning sys-
tem failures. This Comfort Alert
TM
module is designed only for single-
phase systems with scroll compressors that have internal overload pro-
tection. By monitoring and analyzing data from the compressor and the
thermostat demand, the module can detect the cause of electrical and
system related failures without any sensors. A flashing LED indicator
communicates the ALERT code and guides the service technician more
quickly and accurately to the root cause of a problem.
NOTE:
This module does not provide safety protection! The Comfort
Alert
TM
module is a monitoring device and cannot control or shut down
other devices.
LED Description (See Table 1)
POWER LED (Green):
indicates voltage is present at the power con-
nection of the module. ALERT LED (Yellow): communicates an abnor-
mal system condition through a unique flash code. The ALERT LED will
flash a number of times consecutively, pause and then repeat the pro-
cess. The number of consecutive flashes, defined as the Flash Code,
correlates to a particular abnormal condition. Detailed descriptions of
specific ALERT Flash Codes are shown in Table 6 of this manual.
TRIP LED (Red):
indicates there is a demand signal from the thermo-
stat but no current to the compressor is detected by the module. The
TRIP LED typically indicates the compressor protector is open or may
indicate missing supply power to the compressor.
The scroll compressor’s run (R), common (C) and start (S) wires are
routed through the holes in the Comfort Alert
TM
module marked “R,” “C”
and “S.”
24 VAC Power Wiring —
The Comfort Alert
TM
module requires a con-
stant nominal 24 VAC power supply. The wiring to the module’s R and C
terminals must be directly from the indoor unit or thermostat.
The Comfort Alert
TM
module requires a thermostat demand signal to
operate properly.
NOTE:
After the thermostat demand signal is connected, verify that 24
VAC across Y and C
when demand is present
.
TABLE 1:
R-410A Saturation Properties
TEMP.
°
F
PRESSURE
PSIG
TEMP.
°
F
PRESSURE
PSIG
TEMP.
°
F
PRESSURE
PSIG
TEMP.
°
F
PRESSURE
PSIG
TEMP.
°
F
PRESSURE
PSIG
45
129.70
60
169.60
75
217.40
90
274.10
105
340.50
46
132.20
61
172.60
76
220.90
91
278.20
106
345.30
47
134.60
62
175.50
77
224.40
92
282.30
107
350.10
48
137.10
63
178.50
78
228.00
93
286.50
108
355.00
49
139.60
64
181.60
79
231.60
94
290.80
109
360.00
50
142.20
65
184.60
80
235.30
95
295.10
110
365.00
51
144.80
66
187.70
81
239.00
96
299.40
111
370.00
52
147.40
67
190.90
82
242.70
97
303.80
112
375.10
53
150.10
68
194.10
83
246.50
98
308.20
113
380.20
54
152.80
69
197.30
84
250.30
99
312.70
114
385.40
55
155.50
70
200.60
85
254.10
100
317.20
115
390.70
56
158.20
71
203.90
86
258.00
101
321.80
116
396.00
57
161.00
72
207.20
87
262.00
102
326.40
117
401.30
58
163.90
73
210.60
88
266.00
103
331.00
118
406.70
59
166.70
74
214.00
89
270.00
104
335.70
119
412.20
TABLE 2:
18Z38AC Subcooling Charging Chart
Outdoor
Ambient
Indoor Wet Bulb (°F)
57
62
67
72
DB (°F)
Liquid Pressure (psig) at Base Valve
65
239 (8)
240 (8)
245 (8)
250 (8)
70
260 (8)
261 (8)
266 (9)
271 (9)
75
281 (8)
282 (8)
287 (9)
292 (9)
80
303 (8)
304 (8)
309 (9)
314 (9)
85
326 (8)
327 (8)
332 (9)
337 (9)
90
349 (8)
350 (8)
355 (8)
360 (8)
95
374 (7)
375 (7)
380 (8)
385 (8)
100
398 (7)
399 (7)
404 (8)
409 (8)
105
424 (7)
425 (7)
430 (8)
435 (8)
110
450 (7)
451 (7)
456 (7)
461 (7)
115
477 (7)
478 (7)
483 (7)
488 (7)
120
504 (6)
505 (6)
510 (6)
515 (6)
125
533 (5)
534 (5)
539 (5)
544 (6)
