System Service Checks; Maintenance - Lennox ALLIED Commercial TCA180S2B Standard Manual

TABLE 12
TCA210H NORMAL OPERATING PRESSURES
CIRCUIT 1 CIRCUIT 2 CIRCUIT 3 CIRCUIT 4
Outdoor
Coil
Dis. Suc. Dis.
Entering
+10 +5 +10
Air Temp
psig psig psig
65°F
170 77 173
75°F 197 78 198
223 79 225
85°F
255 81 255
95°F
289 83 287
105°F
115°F 329 85 323
TABLE 13
TCA240S NORMAL OPERATING PRESSURES
CIRCUIT 1
Outdoor
Coil
Dis. Suc.
Entering
+10 +5
Air Temp
psig psig
185 69
65°F
212 71
75°F
236 72
85°F
267 73
95°F
105°F 297 74
115°F 335 76
TABLE 14
TCA240H NORMAL OPERATING PRESSURES
CIRCUIT 1 CIRCUIT 2 CIRCUIT 3 CIRCUIT 4
Outdoor
Coil
Dis. Suc. Dis.
Entering
+10 +5 +10
Air Temp
psig psig psig
65°F 179 75 181
75°F 207 76 208
239 78 238
85°F
272 80 270
95°F
307 83 303
105°F
115°F 351 85 342
TABLE 15
TCA300S NORMAL OPERATING PRESSURES
CIRCUIT 1 CIRCUIT 2 CIRCUIT 3 CIRCUIT 4
Outdoor
Coil
Dis. Suc. Dis.
Entering
+10 +5 +10
Air Temp
psig psig psig
185 69 183
65°F
213 72 210
75°F
247 75 241
85°F
280 77 271
95°F
105°F 320 79 309
115°F 361 81 346
Suc. Dis. Suc Dis. Suc.
+5 +10 +5 +10 +5
psig psig psig psig psig
80 172 80 168 80
81 197 81 193 81
82 225 82 221 82
83 257 83 252 83
84 293 85 287 85
86 333 87 327 87
CIRCUIT 2 CIRCUIT 3
Dis. Suc. Dis. Suc.
+10 +5 +10 +5
psig psig psig psig
182 73 183 72
209 75 210 74
233 75 234 75
265 76 264 75
301 77 300 76
340 78 338 78
Suc. Dis. Suc Dis. Suc.
+5 +10 +5 +10 +5
psig psig psig psig psig
79 174 79 176 79
81 203 79 204 80
82 233 80 234 81
83 266 83 266 83
84 301 84 300 85
85 343 86 342 86
Suc. Dis. Suc Dis. Suc.
+5 +10 +5 +10 +5
psig psig psig psig psig
70 186 72 179 71
74 215 76 207 75
77 249 78 240 78
78 281 80 271 79
79 317 81 307 80
80 358 82 345 82
Charge Verification − Approach Method
1− Using the same thermometer, compare liquid temper-
ature to outdoor ambient temperature.
Approach Temperature = Liquid temperature minus
ambient temperature.
2− Approach temperatures should match values in table
16. An approach temperature greater than
dicates an undercharge. An approach temperature
less than
this value
3− Do not use the approach method if system pressures
do not match pressures in tables 9 through 15. The ap-
proach method is not valid for grossly over or under-
charged systems.
APPROACH TEMPERATURES
Liquid Temp. Minus Ambient Temp.
Unit
1st Stage
180S
210S 7°F + 1
240S
(3.9°C + 0.5)
180H
9°F + 1
210H
(5°C + 0.5)
10°F + 1
240H
(5.6°C + 0.5)
14°F + 1
300S
(7.8°C + 0.5)
V− SYSTEMS SERVICE CHECKS
A−Cooling System Service Checks
TCA units are factory charged and require no further adjust-
ment; however, charge should be checked periodically using
the approach method. The approach method compares actual
liquid temperature with the outdoor ambient temperature. See
section IV−CHARGING.
NOTE−When unit is properly charged discharge line pres-
sures should approximate those in tables 9 through 15.
VI−MAINTENANCE
Electrical shock hazard. Turn off power to unit be-
fore performing any maintenance, cleaning or
service operation on the unit.
CAUTION
Danger of sharp metallic edges. Can cause injury.
Take care when servicing unit to avoid accidental
contact with sharp edges.
Page 35
this value
indicates an overcharge.
TABLE 16
2nd Stage 3rd Stage
7°F + 1 7°F + 1
(3.9°C + 0.5) (3.9°C + 0.5)
7°F + 1 8°F + 1
(3.9°C + 0.5) (4.4°C + 0.5) (4.4°C + 0.5)
9°F + 1 9°F + 1
(5°C + 0.5) (5°C + 0.5) (5.6°C + 0.5)
12°F + 1 12°F + 1
(6.7°C + 0.5) (6.7°C + 0.5) (6.7°C + 0.5)
CAUTION
in-
4th Stage
NA
8°F + 1
10°F + 1
12°F + 1