Lennox LCH092H Unit Information page 53

B-Refrigerant Charge and Check - Fin/Tube Coil - TXV
LCH092H, 102H, 120H, 150S, 150H
WARNING-Do not exceed nameplate charge under any
condition.
This unit is factory charged and should require no further
adjustment. If the system requires additional refrigerant, re­
claim the charge, evacuate the system, and add required
nameplate charge.
NOTE - System charging is not recommended below 60°F
(15°C). In temperatures below 60°F (15°C) , the charge
must be weighed into the system.
If weighing facilities are not available, or to check the
charge, use the following procedure:
IMPORTANT - Charge unit in standard cooling mode.
1 Attach gauge manifolds and operate unit in cooling
mode with economizer disabled until system stabilizes
(approximately five minutes). Make sure outdoor air
dampers are closed.
2 Check each system separately with all stages operat­
ing.
3 Use a thermometer to accurately measure the outdoor
ambient temperature.
4 Apply the outdoor temperature to tables 8 through 17
to determine normal operating pressures. Pressures
are listed for sea level applications at 80
5
and 67 F wet bulb return air.
5 Compare the normal operating pressures to the pres­
sures obtained from the gauges. Minor variations in
these pressures may be expected due to differences in
installations. Significant differences could mean that
the system is not properly charged or that a problem
exists with some component in the system. Correct
any system problems before proceeding.
6 If discharge pressure is high, remove refrigerant from
the system. If discharge pressure is low, add refrigerant
to the system.
S Add or remove charge in increments.
S Allow the system to stabilize each time refrigerant
is added or removed.
7 Use the following approach method along with the nor­
mal operating pressures to confirm readings.
TABLE 8
LCH092H Fin/Tube Coil - TXV
CIRCUIT 1
Outdoor
Dis­
Coil
charge
Entering
+10 psig
Air Temp
o
65 F 235
o
75 F 272
o
85 F 312
o
95 F 357
o
105 F 407
o
115 F 460
5
F dry bulb
CIRCUIT 2
Dis­
Suction Suction
charge
+5 psig +10 psig +5 psig
137 262
139 298
142 338
146 380
149 428
154 477
LCH092H Fin/Tube Coil Hot Gas Reheat - TXV
Outdoor
Coil
Entering
Air Temp
o
65 F
o
75 F
o
85 F
o
95 F
o
105 F
o
115 F
Outdoor
Coil
Entering
Air Temp
o
65 F
o
75 F
o
85 F
o
95 F
o
105 F
o
115 F
LCH102H Fin/Tube Coil Hot Gas Reheat - TXV
Outdoor
Coil
Entering
Air Temp
o
65 F
o
75 F
o
85 F
o
95 F
o
105 F
o
115 F
Outdoor
Coil
Entering
Air Temp
655 F
755 F
855 F
955 F
1055 F
1155 F
LCH120H Fin/Tube Coil Hot Gas Reheat - TXV
Outdoor
Coil
Entering
Air Temp
655 F
137
755 F
141
855 F
144
955 F
146
1055 F
149
153 1155 F
Page 53
TABLE 9
CIRCUIT 1
Dis­
Suction
charge charge
+5 psig
+10 psig +10 psig
242 134
279 137
319 140
364 143
414 146
467 151
TABLE 10
LCH102H Fin/Tube Coil - TXV
CIRCUIT 1
Dis­
charge Suction charge
+10 psig +5 psig +10 psig
241 139
277 141
318 143
362 145
411 148
464 150
TABLE 11
CIRCUIT 1
Dis­
Suction
charge charge
+5 psig
+10 psig +10 psig
249 137
285 139
327 141
370 143
420 146
473 148
TABLE 12
LCH120H Fin/Tube Coil - TXV
CIRCUIT 1
Dis­
charge Suction charge
+10 psig +5 psig +10 psig
259 137
297 140
338 143
382 146
431 149
486 151
TABLE 13
CIRCUIT 1
Dis­
Suction
charge charge
+5 psig
+10 psig +10 psig
266 134
303 137
344 140
391 143
443 146
499 149
CIRCUIT 2
Dis­
Suction
+5 psig
262 139
297 143
338 146
379 148
427 151
476 155
CIRCUIT 2
Dis­
Suction
+5 psig
273 141
307 144
348 147
389 149
437 151
486 152
CIRCUIT 2
Dis­
Suction
+5 psig
272 142
306 145
347 148
389 150
436 152
485 154
CIRCUIT 2
Dis­
Suction
+5 psig
283 139
321 142
360 144
406 146
453 148
505 151
CIRCUIT 2
Dis­
Suction
+5 psig
281 139
310 141
358 143
403 145
450 146
497 148