SECTION V: INSTALLATIONS REQUIRING AN
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
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,
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
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 =
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:
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 | 5 |