Sequence of operation – HP H4H3 User Manual
Page 13
INSTALLATION INSTRUCTIONS
3-phase R-410A Split System Heat Pump
506 01 5102 00
13
Figure 14
R-410A 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)
6
8
10
12
14
16
6
8
10
12
14
16
251
78
76
74
72
70
68
364
104
102
100
98
96
94
259
80
78
76
74
72
70
374
106
104
102
100
98
96
266
82
80
78
76
74
72
384
108
106
104
102
100
98
274
84
82
80
78
76
74
395
110
108
106
104
102
100
283
86
84
82
80
78
76
406
112
110
108
106
104
102
291
88
86
84
82
80
78
416
114
112
110
108
106
104
299
90
88
86
84
82
80
427
116
114
112
110
108
106
308
92
90
88
86
84
82
439
118
116
114
112
110
108
317
94
92
90
88
86
84
450
120
118
116
114
112
110
326
96
94
92
90
88
86
462
122
120
118
116
114
112
335
98
96
94
92
90
88
474
124
122
120
118
116
114
345
100
98
96
94
92
90
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.