York GCGA SERIES, Installation Manual

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548086-XIM-C-0814
6 Johnson Controls Unitary Products
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.
SUPERHEAT CHARGING METHOD -
PISTON INDOOR
1. Set the system running in cooling mode by setting the thermostat
at least 6°F below the room temperature and operate system for at
least 10 – 15 minutes.
2. Refer to the technical guide for the recommended airflow and ver-
ify indoor airflow (it should be about 400 SCFM per ton).
3. Measure and record the outdoor ambient (DB) temperature and
the suction pressure at the suction service valve.
4. Using the charging chart located on the unit, find the intersection
of the outdoor ambient dry bulb and the suction pressure obtained
in step 3. This is the recommended suction tube temperature at
the service valve.
5. Measure and record the suction tube temperature at the service
valve and compare to the recommended temperature obtained in
step 4.
6. Add charge if the measured suction temperature in step 5 is above
the recommended value. Remove / recover refrigerant if the mea-
sured suction temperature is below the recommended value.
SUBCOOLING CHARGING METHOD - TXV INDOOR
1. Set the system running in cooling mode by setting the thermostat
at least 6°F below the room temperature and operate system for at
least 10 – 15 minutes.
2. Refer to the technical guide for the recommended indoor airflow
and verify it is correct (it should be about 400 SCFM per ton).
3. Measure and record the indoor wet bulb (WB) and the outdoor
ambient dry bulb (DB) temperature.
4. Using the charging chart located on the unit, find the intersection
of the indoor wet bulb and the outdoor dry bulb. This is the recom-
mended liquid pressure (and subcooling value).
5. Measure and record the pressure at the liquid valve pressure port
and compare to the value obtained in step 4.
6. Add charge if the measured liquid pressure is lower than the rec-
ommended value. Remove / recover charge if the measured liquid
pressure is above the recommended value.
Condenser subcooling is obtained by calculating the difference of the
saturated refrigerant temperature of the pressure measured at the liquid
base valve and the liquid tube temperature as measured at the liquid
base valve.
Subcooling Temp. (TC) = Saturated Temp. (TS) – Liquid Temp. (T).
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.
Example: The suction tube temperature listed on the table at the
intersection of the outdoor DB and the suction pressure is 63°F.
Temperature of the suction tube at the service valve is 68°F. It would
be necessary to add refrigerant to drop the suction tube temperature
to 63°F.
Example: The liquid pressure listed at the intersection of the indoor
WB and the outdoor DB 320 psig. Pressure at the liquid valve is 305
psig. It would be necessary to add refrigerant to increase the liquid
pressure to 320 psig.
IT IS UNLAWFUL TO KNOWINGLY VENT, RELEASE OR DIS-
CHARGE REFRIGERANT INTO THE OPEN AIR DURING
REPAIR, SERVICE, MAINTENANCE OR THE FINAL DISPOSAL
OF THIS UNIT.
TABLE 2: R-22 Saturation Properties
Press Temp Press Temp Press Temp Press Temp Press Temp Press Temp Press Temp
psig °F psig °F psig °F psig °F psig °F psig °F psig °F
70 41 100 59 130 74 160 87 190 98 220 108 250 117
72 42 102 60 132 75 162 88 192 99 222 109 252 118
74 44 104 61 134 76 164 88 194 99 224 109 254 118
76 45 106 62 136 77 166 89 196 100 226 110 256 119
78 46 108 63 138 78 168 90 198 101 228 111 258 119
80 48 110 64 140 78 170 91 200 101 230 111 260 120
82 49 112 65 142 79 172 91 202 102 232 112 262 121
84 50 114 66 144 80 174 92 204 103 234 112 264 121
86 51 116 67 146 81 176 93 206 103 236 113 266 122
88 52 118 68 148 82 178 94 208 104 238 114 268 122
90 54 120 69 150 83 180 94 210 105 240 114 270 123
92 55 122 70 152 84 182 95 212 105 242 115 272 123
94 56 124 71 154 84 184 96 214 106 244 115 274 124
96 57 126 72 156 85 186 97 216 107 246 116 276 125
98 58 128 73 158 86 188 97 218 107 248 117 278 125