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Checking Charge Using Normal Operating Pressures
IMPORTANT
Use table 8 to help perform maintenance checks.
Table 8 is not a procedure for charging the system. Mi-
nor variations in these pressures may be due to differ-
ences in installations. Significant deviations could
mean that the system is not properly charged or that
a problem exists with some component in the system.
TABLE 7
Approach Values
13ACD Model −018 −024 −030 −036 −042 −048 −060
Temp. °F (°C) 6 (3.3) 10 (5.6) 11 (6) 9 (5) 6 (3.3) 6 (3.3) 8 (4.4)
Approach Value is the Liquid Line Temperature minus Outdoor Ambient Temperature [ºF (ºC) + 1ºF (0.5ºC)]
NOTE − For best results, use the same digital thermometer to check both outdoor ambient and liquid temperatures.
TABLE 8
Normal Operating Pressures In psig (liquid and suction +/− 2 psig)*
Normal Operating Pressures
13ACD
Model
−018 −024 −030 −036 −042
−048−1, −2
units
−048
−060
Values below are typical pressures; indoor unit match up, indoor air quality equipment, and indoor load will cause the
pressures to vary.
*Temp. 5F
(5C)
Liquid Line Pressure/Vapor Line Pressure
Expansion Valve (TXV)
65 (18) 141 / 80 147 / 79 141 / 76 145 / 74 143 / 78 145 / 80 140 / 77 151 / 76
70 (21) 154 / 81 159 / 79 154 / 76 157 / 75 153 / 79 157 / 81 152 / 77 164 / 77
75 (24) 166 / 81 173 / 80 167 / 77 170 / 76 167 / 80 170 / 81 165 / 77 177 / 78
80 (27) 180 / 82 187 / 81 181 / 78 186 / 76 182 / 80 184 / 82 179 / 78 192 / 78
85 (29) 195 / 82 218 / 82 195 / 78 201 / 77 198 / 81 198 / 82 192 / 78 207 / 79
90 (32) 209 / 83 202 / 81 210 / 79 217 / 77 215 / 81 214 / 83 209 / 80 223 / 80
95 (35) 222 / 83 234 / 82 227 / 80 234 / 78 231 / 82 230 / 84 227 / 81 240 / 80
100 (38) 244 / 84 251 / 83 249 / 81 251 / 79 249 / 83 247 / 84 243 / 81 259 / 81
105 (41) 258 / 85 267 / 84 260 / 81 268 / 79 268 / 84 265 / 85 261 / 82 277 / 81
110 (43) 276 / 85 287 / 84 278 / 82 288 / 80 287 / 84 283 / 85 279 / 83 297 / 82
115 (45) 294 / 86 307 / 85 299 / 83 309 / 81 308 / 85 303 / 86 296 / 83 318 / 83
Fixed Orifice (RFC)
65 (18) 144 / 73 147 / 68 140 / 66 150 / 67 147 / 70 145 / 70 143 / 73 150 / 67
70 (21) 157 / 76 160 / 71 152 / 68 162 / 70 158 / 72 156 / 72 154 / 75 163 / 70
75 (24) 167 / 78 173 / 74 166 / 71 176 / 72 171 / 75 170 / 75 167 / 78 177 / 72
80 (27) 182 / 80 189 / 77 180 / 74 190 / 74 184 / 77 183 / 78 180 / 79 191 / 75
85 (29) 196 / 82 203 / 79 196 / 76 205 / 76 198 / 78 198 / 80 193 / 81 207 / 77
90 (32) 211 / 84 219 / 81 211 / 79 220 / 78 213 / 80 213 / 82 207 / 82 221 / 79
95 (35) 225 / 84 238 / 83 227 / 80 237 / 79 228 / 81 230 / 84 221 / 84 239 / 80
100 (38) 242 / 86 255 / 85 294 / 82 255 / 80 245 / 82 246 / 85 237 / 85 256 / 81
105 (41) 256 / 86 272 / 86 262 / 83 273 / 81 262 / 84 264 / 86 253 / 86 274 / 83
110 (43) 278 / 88 294 / 87 282 / 84 291 / 83 281 / 84 282 / 87 269 / 87 295 / 84
115 (45) 293 / 88 317 / 88 302 / 86 314 / 84 300 / 85 301 / 88 289 / 88 315 / 85
*Temperature of the air entering the outside coil.