Johnson Controls 13 SEER Section Vi Evacuation, Section Vii System Charge, Temp F, Psig

Models: 13 SEER

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SECTION VI: EVACUATION

347337-UIM-A-0408

SECTION V: INSTALLATIONS REQUIRING AN ADD-ON TXV KIT

For installations requiring a TXV kit, refer to the Installation Instructions accompanying the TXV kit.

Schrader valve core MUST NOT be installed with TXV installation. Poor system performance or system failure could result.

SECTION VI: EVACUATION

It will be necessary to evacuate the system to 500 microns or less. If a leak is suspected, leak test with dry nitrogen to locate the leak. Repair the leak and test again.

To verify that the system has no leaks, simply close the valve to the vac- uum pump suction to isolate the pump and hold the system under vac- uum. Watch the micron gauge for a few minutes. If the micron gauge indicates a steady and continuous rise, it’s an indication of a leak. If the gauge shows a rise, then levels off after a few minutes and remains fairly constant, it’s an indication that the system is leak free but still con- tains moisture and may require further evacuation if the reading is above 500 microns.

SECTION VII: SYSTEM CHARGE

The factory charge in the outdoor unit includes enough charge for the unit, a 15 ft. line set, and the smallest indoor coil match-up. Some indoor coil matches may require additional charge. See tabular data sheet provided in unit literature packet for charge requirements.

Do not leave the system open to the atmosphere.

The “TOTAL SYSTEM CHARGE” must be permanently stamped on the unit data plate.

Total system charge is determined as follows:

1.Determine outdoor unit charge from tabular data sheet.

2.Determine indoor coil adjustment from tabular data sheet.

3.Calculate the line charge using the tabular data sheet if line length is greater than 15 feet.

4.Total system charge = item 1 + item 2 + item 3.

5.Permanently stamp the unit data plate with the total amount of refrigerant in the system.

Use the following charging method whenever additional refrigerant is required for the system charge.

Refrigerant charging should only be carried out by a qualified air conditioning contractor.

Compressor damage will occur if system is improperly charged. On new system installations, charge system per tabular data sheet for the matched coil and follow guidelines in this instruction.

If a calibrated charging cylinder or accurate weighing device is avail- able, add refrigerant accordingly. Otherwise, model-specific charging charts are provided on the access panel of the unit. If mix matched TXV indoor coils are used with these models, the following subcooling charg- ing method must be used. Superheat charging charts are not valid with TXV equipped systems.

SUBCOOLING CHARGING METHOD - MIXED MATCH COILS

The recommended subcooling is 10°F

1.Set the system running in the cooling mode by setting the thermo- stat at least 6°F below the room temperature.

2.Operate the system for a minimum of 15-20 minutes.

3.Refer to the tabular data sheet for the recommended airflow and verify this indoor airflow (it should be about 400 SCFM per ton).

4.Measure the liquid refrigerant pressure P and temperature T at the service valve.

5.Calculate the saturated liquid temperature ST from Table 2.

6.Subcooling temperature TC = Saturated Temperature (ST) - Liquid Temp (T).

Example: The pressure P and temperature T measured at the liq- uid service port is 196 psig and 90°F, respectlvely. From Table 2, the saturated temperature for 196 psig is 100°F. The subcooling temperature TC = 100°-90°=10°F

Add charge if the calculated subcooling temperature TC in Step 6 is lower than the recommended level. Remove and recover the refrigerant if the subcooling TC is higher than the recommended level. See Table 2.

Check flare caps on service ports to be sure they are leak tight. DO NOT OVERTIGHTEN (between 40 and 60 inch - lbs. maximum).

TABLE 2: R-22 Saturated Properties

Pressure

Temp °F

Pressure

Temp °F

Pressure

Temp °F

Pressure

Temp °F

Pressure

Temp °F

Pressure

Temp °F

PSIG

PSIG

PSIG

PSIG

PSIG

PSIG

 

 

 

 

 

 

80

48

110

64

140

78

170

91

200

101

230

111

82

49

112

65

142

79

172

91

202

102

232

112

84

50

114

66

144

80

174

92

204

103

234

112

86

51

116

67

146

81

176

93

206

103

236

113

88

52

118

68

148

82

178

94

208

104

238

114

90

54

120

69

150

83

180

94

210

105

240

114

92

55

122

70

152

84

182

95

212

105

242

115

94

56

124

71

154

84

184

96

214

106

244

115

96

57

126

72

156

85

186

97

216

107

246

116

98

58

128

73

158

86

188

97

218

107

248

117

100

59

130

74

160

87

190

98

220

108

250

117

102

60

132

75

162

88

192

99

222

109

252

118

104

61

134

76

164

88

194

99

224

109

254

118

106

62

136

77

166

89

196

100

226

110

256

119

108

63

138

78

168

90

198

101

228

111

258

119

Johnson Controls Unitary Products

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Johnson Controls 13 SEER Section Vi Evacuation, Section Vii System Charge, Subcooling Charging Method - Mixed Match Coils