Lennox GCS16R-411-100

Page 30
4- Read liquid line pressure from gauge and convert to
condensing temperature using standard HCFC22
temperature/pressure conversion chart (or conver
sion scale on gauge).
5- The difference between the liquid line temperature
(from step 3) and the conversion temperature (from
step 4) is subcooling (subcooling = conversion tem
perature minus liquid temperature). Subcooling tem
perature should approximate the values given in table
12. Add refrigerant to increase subcooling and re
move refrigerant to reduce subcooling.
MODEL NO.
Subcooling F at Various Ambient Temps.
75F85F95F 105F115F
GCS16R-411
65F
GCS16H-311
GCS16H-261 14 14 14 14 12 8
12
18 18 16 14 12 8
915161717
TABLE 12
GCS16-411 18 18 16 14 12 8
GCS16-511/513
GCS16-651/653
GCS16R-511 and GCS16R-651 ONLY
(Approach Method)
6- Check ambient (outdoor) temperature.
7- If ambient temperature is above 60F (15C), place
thermometer in well and read temperature.
8- Approach temperature is the difference between am
bient and liquid line temperatures (Approach = liquid
minus ambient.) Approach temperature should be
4F (2C) for GCS16-511/513 and GCS16R-511
units. Approach temperature should be 9F (5C) for
GCS16-651/653 and GCS16R-651 units. Refrigerant
must be added to lower approach temperature. Re
move refrigerant from system to increase approach
temperature.
NOTE - Use table 13 as a general guide for performing
maintenance checks. When unit is properly charged
(whether by approach or subcooling method) line pres
sures should approximate those given in table 13.
Table 13 is not a procedure for charging the system.
Minor variations in these pressures may be expected
due to differences in installations. Significant devi
ations could mean that the system is not properly
charged or that a problem exists with some component
in the system. Used prudently, table 13 could serve as
a useful service guide.
NORMAL OPERATING PRESSURES
LIQ.
+ 10
SUC.
+ 5
85 F 95 F 105 F
PSIG PSIG
LIQ.
+ 10
SUC.
+ 5
PSIG PSIG
115 F65 F
LIQ.
+ 10
SUC.
+ 5
PSIG PSIG
LIQ.
+ 10
SUC.
+ 5
PSIG PSIG
LIQ.
+ 10
SUC.
+ 5
PSIG PSIG
LIQ.
+ 10
SUC.
+ 5
PSIG PSIG
75 F
GCS16H-261
GCS16H-311
GCS16-411/413
GCS16R-411
GCS16-511/513
GCS16R-511
GCS16-651/653
GCS16R-651
149
154
146
158
146 55
58
57
64
55 182
188
182
190
178
66
69
66
66
68
216
223
214
222
210 73
76
73
74
73 246
256
252
255
244 76
79
78
77
78 282
292
287
290
289 78
82
83
83
84 318
326
328
330
335 80
84
87
87
89
MODEL NO.
TABLE 13