Sequence Of Operation - International comfort products H4H3 Series Installation Instructions Manual

INSTALLATION INSTRUCTIONS
Figure 14
Measured Liquid
Subcooling Temperature (°F)
Pressure (psig)
6
251 78
259 80
266 82
274 84
283 86
291 88
299 90
308 92
317 94
326 96
335 98
345 100

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.
506 01 5102 00
R-410A Required Liquid Line Temperature (°F) - Cooling Mode
Rating Plate (required)
8 10 12 14
76 74 72 70
78 76 74 72
80 78 76 74
82 80 78 76
84 82 80 78
86 84 82 80
88 86 84 82
90 88 86 84
92 90 88 86
94 92 90 88
96 94 92 90
98 96 94 92
3-phase R-410A Split System Heat Pump
Measured Liquid
Pressure (psig)
16
68 364 104
70 374 106
72 384 108
74 395 110
76 406 112
78 416 114
80 427 116
82 439 118
84 450 120
86 462 122
88 474 124
90
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
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.
Rating Plate (required)
Subcooling Temperature (°F)
6 8 10 12 14
102 100 98 96
104 102 100 98
106 104 102 100
108 106 104 102
110 108 106 104
112 110 108 106
114 112 110 108
116 114 112 110
118 116 114 112
120 118 116 114
122 120 118 116
(if used). If
16
94
96
98
100
102
104
106
108
110
112
114
outdoor
13