Page 10
2 - Approach temperature should be as indicated in
table 3 for each stage. An approach temperature
greater than this value indicates an undercharge.
An approach temperature less than this value
indicates an overcharge.
A - Add or remove charge in increments.
B - Allow system to stabilize at least 5 minutes each
time refrigerant is added or removed.
3 - Do not use the approach method if system pressures
do not match pressures in table 4 except when the
outdoor ambient temperature is below 65ºF (18ºC).
The approach method is not valid for grossly over or
undercharged systems.
TABLE 3. HFC-410A Approach Temperatures*
Models
Approach
Temperature (ºF)
(+/-1)
Approach
Temperature (ºC)
(+/-.05)
ELP090S4S /
ELA090
7.0
3.9
ELP120S4S /
ELA120
6.0
3.3
*Approach temperature method valid at full load.
TABLE 4. HFC-410A Normal Operating Pressures – Cooling Mode (Liquid
±
10 and Suction
±
5 psig)**
Temp*
ELP090 / ELA090
ELP120 / ELA120
Liquid
Suction
Liquid
Suction
65º F (18º C)
226
119
247
132
75º F (24º C)
261
125
291
136
85º F (29º C)
303
129
333
138
95º F (35º C)
349
133
370
140
105º F (41º C)
404
135
437
142
115º F (46º C)
462
137
495
144
125º F (52º C)
525
136
562
146
STD. CFM
2760
4000
*Temperature of air entering outdoor coil.
Liquid and suction pressures measured via condenser service valve ports.
** Indoor conditions – 80° F Dry Bulb and 67° F Wet Bulb.
TABLE 5. HFC-410A Normal Operating Pressures – Heating Mode (Liquid
±
10 and Suction
±
5 psig)**
Temp*
ELP090 / ELA090
ELP120 / ELA120
Liquid
Suction
Liquid
Suction
60º F (15º C)
364
121
335
115
50º F (10º C)
343
100
322
101
40º F (4º C)
324
83
308
86
30º F (-1º C)
311
72
294
72
20º F (-6º C)
297
57
280
58
10º F (-12º C)
280
44
266
44
STD. CFM
2760
4000
*Temperature of air entering outdoor coil.
Liquid and suction pressures measured via condenser service valve ports.
** Indoor conditions – 70° F.
