Sequence of operation – HP H2H3 User Manual
Page 13
INSTALLATION INSTRUCTIONS
3-phase R-22 Split System Heat Pump
506 01 5001 00
13
Figure 16
R-22 Required Liquid Line
Temperature (
°F) - Cooling Mode
Measured Liquid
Pressure (psig)
Rating Plate (required)
Subcooling Temperature (
°F)
Measured Liquid
Pressure (psig)
Rating Plate (required)
Subcooling Temperature (
°F)
5
10
15
20
5
10
15
20
134
71
66
61
56
233
107
102
97
92
141
74
69
64
59
243
110
105
100
95
148
77
72
67
62
253
113
108
103
98
156
80
75
70
65
264
116
111
106
101
163
83
78
73
68
274
119
114
109
104
171
86
81
76
71
285
122
117
112
107
179
89
84
79
74
297
125
120
115
110
187
92
87
82
77
309
128
123
118
113
196
95
90
85
80
321
131
126
121
116
205
98
93
88
83
331
134
129
124
119
214
101
96
91
86
346
137
132
127
122
223
104
99
94
89
359
140
135
130
125
SEQUENCE OF OPERATION
A. COOLING MODE
On a call for cooling, the thermostat makes circuits R-O,
R-Y , and R-G. Circuit R-O energizes reversing valve,
switching it to cooling position. Circuit R-Y energizes
contactor, starting outdoor fan motor and compressor.
Circuit R-G energizes indoor unit blower relay, starting
indoor blower motor.
When thermostat is satisfied, its contacts open,
de-energizing contactor and blower relay. Compressor
and motors stop.
NOTE: If indoor unit is equipped with a time-delay relay
circuit, the blower runs an additional length of time to
increase system efficiency. (Applies to both cooling and
heating modes.)
NOTE: Low ambient cooling feature allows unit to
operate safely in cooling mode down to 0
° F outdoor
ambient.
B. HEATING MODE
On a call for heating, the thermostat makes circuits R-Y
and R-G (circuit R-O is NOT made, and the reversing
valve stays in the de-energized, heating position). Circuit
R-Y energizes contactor, starting outdoor fan motor and
compressor. Circuit R-G energizes indoor blower relay,
starting blower motor. If the room temperature continues
to fall, circuit R-W2 is made through the second-stage
room thermostat bulb. Circuit R-W2 energizes a
sequencer, bringing on the first bank supplemental
electric heat and providing electrical potential to the
second heater sequencer (if used). If outdoor
temperature falls below the setting of the outdoor
thermostat (field-installed option), contacts close to
complete the circuit and bring on the second bank of
supplemental electric heat.
When the thermostat is satisfied, its contacts open,
de-energizing contactor, blower relay, and sequencer.
Compressor, motors, and heaters stop.