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Bryant R-22 561G User Manual

Page 5

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B.

Cooling Only Procedure—Indoor unit equipped with

TXV—Subcooling Method

Factory charge and subcooling are shown on unit information
plate. To check charge, follow the procedure below.
NOTE: If subcooling charging conditions are not favorable,
charge must be weighed in accordance with unit rating plate, ±0.6
oz/ft. of 3/8-in. liquid line above or below 15 ft, respectively.
Favorable conditions fall within the ranges given on the charging
chart on the outdoor unit plate.
EXAMPLE:
To calculate additional charge required for a 25-ft. line set; 25 ft -
15 ft = 10 ft X 0.6 oz/ft = 6 oz of additional charge.
This system requires charging by the subcooling method.

1. Operate unit a minimum of 10 minutes before checking

charge.

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 of electronic thermometer to liquid line near
outdoor coil.

4. Refer to unit rating plate for required subcooling tempera-

ture.

5. Refer to Table 3. Find the point where required subcooling

temperature intersects measured liquid service valve pres-
sure.

6. To obtain required subcooling temperature at the specific

liquid line pressure, add refrigerant if liquid line tempera-
ture is higher than indicated or reclaim refrigerant if
temperature is lower. Allow a tolerance of ±3°F.

NOTE: In long-line applications, See the Residential Split Sys-
tem Long-Line Application Guideline for special charging require-
ments.

CARE AND MAINTENANCE

For continuing high performance and to minimize possible equip-
ment failure, it is essential that periodic maintenance be performed
on this equipment.Consult your servicing contractor or Owner’s
Manual for proper frequency of maintenance. Frequency of
maintenance may vary depending upon geographic areas, such as
coastal applications.

Leave Owner’s Manual with homeowner. Explain system opera-
tion and maintenance procedures outlined in manual.

TABLE 3—REQUIRED SUBCOOLING TERMPERATURE

(°F)

LIQUID

PRESSURE AT

SERVICE VALVE

REQUIRED SUBCOOLING TERMPERATURE (°F)

(PSIG)

5

10

15

20

134

71

66

61

56

141

74

69

64

59

148

77

72

67

62

156

80

75

70

65

163

83

78

73

68

171

86

81

76

71

179

89

84

79

74

187

92

87

82

77

196

95

90

85

80

205

98

93

88

83

214

101

96

91

86

223

104

99

94

89

233

107

102

97

92

243

110

105

100

95

253

113

108

103

98

264

116

111

106

101

274

119

114

109

104

285

122

117

112

107

297

125

120

115

110

309

128

123

118

113

321

131

126

121

116

331

134

129

124

119

346

137

132

127

122

359

140

135

130

125

24 VAC HOT

24 VAC COM

R

C

G

W/W1

Y/Y2

R

C

C

A/C

THERMOSTAT

Typical

FAN COIL

AIR

CONDITIONER

G

W2

HEAT STAGE 1

COOL STAGE 1

INDOOR FAN

24 VAC HOT

24 VAC COM

R

C

G

W/W1

Y/Y2

R

C

C

A/C

THERMOSTAT

Typical

FURNACE

AIR

CONDITIONER

Y

G

W

HEAT STAGE 1

COOL STAGE 1

INDOOR FAN

A02326

Fig. 6—Generic Wiring Diagram

(See Thermostat Installation Instructions for wiring specific unit combinations)

—5—