Lennox Elite Series Installation Instructions Manual page 19

8UBCOOLING
2
USE COOLING
MODE
60°F (15 °) --
USE HEATING
MODE
Check the airflow as illustrated in figure 32 to be sure the indoor airflow is as required.
(Make any air flow adjustments before continuing with the following procedure0
Measure outdoor ambient temperature; determine whether to use cooling mode or
heating mode to check charge.
3 Connect gauge set.
4 Check liquid and vapor line pressures. Compare pressures with either heat or cooling mode
normal operating pressures in tables 8 and 9 (second stage - high capacity),
NOTE - The reference table is a general guide. Expect m#nor pressure variations. Significant
differences may mean improper charge or other system problem.
5 Set thermostat for heat/cool demand, depending on mode being used:
Using cooling mode--When the outdoor ambient temperature is 60°F (15°C) and above.
Target subcooling values (second stage - high capacity) in table 8 are based on 70 to 80°F
(21-27°C) indoor return air temperature; if necessary, operate heating to reach that
temperature range; then set thermostat to cooling mode setpoint to 68°F (20°C) which should
call for second stage (high capacity) cooling. When pressures have stabilized, continue with
step 6.
%
SAT o
LIQ o -
SC o =
Using heating mode--When the outdoor ambient temperature is below 60°F (15°C). Target
subcooling values (second stage - high capacity) in table 9 are based on 65-75°F (18-24°C)
indoor return air temperature; if necessary, operate cooling to reach that temperature range;
then set thermostat to heating mode setpoint to 77°F (25°C) which should call for second stage
(high capacity) heating. When pressures have stabilized, continue with step 6.
6 Read the liquid line temperature; record in the LIQ ° space.
7 Read the liquid line pressure; then find its corresponding temperature in the temperature/
pressure chart listed in table 10 and record it in the SAT ° space.
8 Subtract LIQ ° temp. from SAT ° temp. to determine subcooling; record it in SC ° space.
9 Compare SC ° results with table below, being sure to note any additional charge for line set
and/or match-up.
10 If subcooling value is greater than shown in tables 4 through 7 for the applicable unit, remove
refrigerant; if less than shown, add refrigerant.
11 If refrigerant is added or removed, repeat steps 4 through 10 to verify charge.
Figure 34. Using Subcooling Method -- Second Stage (High Capacity)
Table 4. XP16-024
Target
INDOOR HEAT Subcooling **Add
MATCHUP PUMP Heat Cool charge
(+5°F) (+I°F)
CBX26UH-018 20 8 1 5
CBX26UH-024 20 8 1 5
CB27UH-024 12 6 O 12
CB27UH-030 13 9 1 12
CB3OU 21/26 12 6 O 12
CB3OU 31 13 9 1 12
CBX32M-018/024 12 6 O 12
CBX32M-030 13 9 1 12
CBX32MV 024/030 13 9 1 12
CBX32MV 036 12 9 O 10
CH33-25B 17 4 O O
CH33-36A-2F 12 6 O 10
CH3_36B_F 17 4 O O
CH33 36C 2F 12 7 1 2
CR33-24A/B-F 20 4 O O
CR33-3O/36A/B/C-F 20 8 1 6
CR33 48 21 9 O 3
CX34_5A/_6F 12 6 O 12
CX34-31A/B-6F 20 9 1 12
CX34-36A/B/C-6F 17 5 O 5
CX34 38A/B 6F SerialNo#before6007K 31 7 O 8
CX34_8A/_6F SerialNo#6007K andafter 10 8 O 11
CX34-19 18 4 O 1
Table 5. XP16-036
Target
INDOOR HEAT Subcooling **Add
MATCHUP PUMP Heat Cool charge
(*5°F) (*I°F)
ililili'11" .....
CH23_1 17 7 O 13
CH23-65 12 8 1 10
CBX26UHq330 25 8 1 14
CBX26UH 036 25 8 1 14
CB27UH-036 17 8 2 4
CB27UH-042 17 8 2 4
CB3OU_I 17 6 O O
CB3OU-41/46 17 8 2 4
CBX32M-030 17 6 O O
CBX32M-036 17 8 2 4
CBX32MV-024/030 17 6 O O
CBX32MV 036 17 8 2 4
C33 44C 17 8 1 14
CH33-42B-2F 17 7 O 13
CH33_44/48_2F 12 8 1 8
CH33_48C_F 10 8 1 6
CH33-43B 9 10 1 6
CH33_49C 9 10 1 6
CR33_48B/C_ 25 8 2 O
CR33-50/60C-F 25 9 0 14
CX34 38A/B_F se.al No#before6007K 31 7 1 5
CX34 38A/B 6FSet_alNo#6OOTKandafter 10 8 1 12
CX34-43B/C-6F 10 8 1 6
CX34 6OD 9 9 O 14
**Amount of charge required in additional to charge shown on unit nameplate.
(Remember to consider Iine set length difference.)
Page 19
XP16 SERIES