KeepRite C4A3 Installation Instructions Manual - page 10
INSTALLATION INSTRUCTIONS
R−410A Split System Air Conditioner
10
421 01 5100 01
REFRIGERANT CHARGE
Outdoor units are shipped with a refrigerant charge to
match a specific indoor coil and 15 feet of refrigerant line.
If shorter or longer refrigerant lines or a different indoor
coil are used, the charge will have to be adjusted.
For different line lengths, add or remove charge based on
0.6 ounces charge per foot of difference. For example, a
25 foot line set is 10 feet longer than the specified 15 feet.
Add 0.6 ounces charge for each of the extra 10 feet:
10 x 0.6 = 6.0 ounces additional charge
This outdoor unit is designed for use only with indoor coils
that utilize a hard shut−off TXV refrigerant metering de-
vice. With a hard shut−off indoor TXV, use the subcooling
method to make final charge adjustments:
1. Operate unit a minimum of 10 minutes before
checking charge.
NOTE: If outdoor unit has a 2−speed fan motor,
motor will operate in low speed when outdoor am-
bient temperature is below 82 °F. Pull one of the
yellow low voltage wires off the fan control and the
unit will default to high speed fan for servicing. Re-
connect wire after servicing.
2. Measure liquid service valve pressure by attaching
an accurate gauge to service port.
3. Measure liquid line temperature by attaching an
accurate thermistor type sensor or electronic ther-
mometer to liquid line near outdoor coil.
4. Refer to unit rating plate for required subcooling
temperature.
5. Refer to Figure 12. Find the required liquid line
temperature where the rating plate subcooling
temperature intersects measured liquid service
valve pressure.
6. If the measured liquid line temperature is higher
than the chart number, add refrigerant to lower the
measured temperature.
NOTE: When adding refrigerant, charge in liquid form,
using a flow restricting device, into the suction port.
If the measured liquid line temperature is lower than the
chart number, reclaim refrigerant to raise the measured
temperature.
Tolerance is 3 °F.
Figure 12
R−410A Required Liquid Line Temperature (°F)
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
189
60
58
56
54
52
50
326
96
94
92
90
88
86
195
62
60
58
56
54
52
335
98
96
94
92
90
88
202
64
62
60
58
56
54
345
100
98
96
94
92
90
208
66
64
62
60
58
56
354
102 100
98
96
94
92
215
68
66
64
62
60
58
364
104 102 100
98
96
94
222
70
68
66
64
62
60
374
106 104 102 100
98
96
229
72
70
68
66
64
62
384
108 106 104 102 100
98
236
74
72
70
68
66
64
395
110
108 106 104 102 100
243
76
74
72
70
68
66
406
112
110
108 106 104 102
251
78
76
74
72
70
68
416
114
112
110
108 106 104
259
80
78
76
74
72
70
427
116
114
112
110
108 106
266
82
80
78
76
74
72
439
118
116
114
112
110
108
274
84
82
80
78
76
74
450
120 118
116
114
112
110
283
86
84
82
80
78
76
462
122 120
118
116
114
112
291
88
86
84
82
80
78
474
124 122 120 118
116
114
299
90
88
86
84
82
80
486
126 124 122 120 118
116
308
92
90
88
86
84
82
499
128 126 124 122 120
118
317
94
92
90
88
86
84
511
130 128 126 124 122 120
SEQUENCE OF OPERATION
With power supplied to indoor and outdoor units, trans-
former is energized.
On a call for cooling, the thermostat makes circuits R−Y
and R−G. Circuit R−Y energizes contactor, starting out-
door 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 in-
crease system efficiency.