Page 32
506601−01
Table 9
.
HFC−410A Temperature (°F) − Pressure (Psig)
°F
Psig
°F
Psig
°F
Psig
°F
Psig
°F
Psig
°F
Psig
°F
Psig
°F
Psig
32
100.8
48
137.1
63
178.5
79
231.6
94
290.8
110
365.0
125
445.9
141
545.6
33
102.9
49
139.6
64
181.6
80
235.3
95
295.1
111
370.0
126
451.8
142
552.3
34
105.0
50
142.2
65
184.3
81
239.0
96
299.4
112
375.1
127
457.6
143
559.1
35
107.1
51
144.8
66
187.7
82
242.7
97
303.8
113
380.2
128
463.5
144
565.9
36
109.2
52
147.4
67
190.9
83
246.5
98
308.2
114
385.4
129
469.5
145
572.8
37
111.4
53
150.1
68
194.1
84
250.3
99
312.7
115
390.7
130
475.6
146
579.8
38
113.6
54
152.8
69
197.3
85
254.1
100
317.2
116
396.0
131
481.6
147
586.8
39
115.8
55
155.5
70
200.6
86
258.0
101
321.8
117
401.3
132
487.8
148
593.8
40
118.0
56
158.2
71
203.9
87
262.0
102
326.4
118
406.7
133
494.0
149
601.0
41
120.3
57
161.0
72
207.2
88
266.0
103
331.0
119
412.2
134
500.2
150
608.1
42
122.6
58
163.9
73
210.6
89
270.0
104
335.7
120
417.7
135
506.5
151
615.4
43
125.0
59
166.7
74
214.0
90
274.1
105
340.5
121
423.2
136
512.9
152
622.7
44
127.3
60
169.6
75
217.4
91
278.2
106
345.3
122
428.8
137
519.3
153
630.1
45
129.7
61
172.6
76
220.9
92
282.3
107
350.1
123
434.5
138
525.8
154
637.5
46
132.2
62
175.4
77
224.4
93
286.5
108
355.0
124
440.2
139
532.4
155
645.0
47
134.6
78
228.0
109
360.0
140
539.0
INSTALLING ISOLATION GROMMETS
Locate the isolation grommets (provided). Slide grommets
onto vapor and liquid lines. Insert grommets into piping
panel to isolate refrigerant lines from sheet metal edges.
TWO ISOLATION GROMMETS ARE
PROVIDE FOR THE LIQUID AND
SUCTION LINE PIPE PANEL PASS
THROUGH.
LIQUID LINE
SUCTION LINE
REAR VIEW OF UNIT EXTERIOR
PIPING PANEL
Figure 23. Isolation Grommets
System Operations
IMPORTANT
Some scroll compressor have internal vacuum protector
that will unload scrolls when suction pressure goes
below 20 psig. A hissing sound will be heard when the
compressor is running unloaded. Protector will reset
when low pressure in system is raised above 40 psig. DO
NOT REPLACE COMPRESSOR.
The heat pump control (A175) provides the following
functions:
S
Demand defrost algorithm
S
Field−selectable defrost termination temperatures
S
Internal switching of outputs
S
Compressor anti−short−cycle delay.
S
Five−strikes lockout safety function
S
High (S4) and low (S87) pressure switches
S
Ambient (RT13), coil (RT21) and discharge line
(RT28) temperatures monitoring and protection.
COMPRESSOR PROTECTION ANTI−SHORT
CYCLE DELAY
The heat pump control protects the compressor from:
S
Short cycling (five minutes) when there is initial power
up
S
Interruption in power to the unit
S
Pressure or sensor trips
S
Delay after Y1 demand is removed.
In non−communicating systems the delay is set for 300
seconds (five minutes) and can not be changed. To
override timer when active or inactive, place a jumper on
the field test pins between 1 and 2 seconds.
In communicating system, the icomfort Touch
®
thermostat
has a separate built−in 5−minute non−adjustable short cycle
protection.
