Lennox Merit Series 13ACX Installation Instructions Manual page 19

START: Measure outdoor ambient temperature
USE WEIGH-IN METHOD
Weigh-in or remove refrigerant
based upon line length
ºF*
40
45
50
55
60
65
70
75
80
85
90
95
100
105
If refrigerant is
110
REMOVED, retest to
115
confirm that unit is
properly charged. * Dry−bulb temperature (ºF) of entering outdoor ambient air.
If value is LESS than
shown, then REMOVE
refrigerant.
ABOVE or
BELOW
39ºF and
BELOW
SHº (Superheat) Values (+/−5ºF)
Wet Bulb (air entering indoor coil)
50 52 54 56 58 60 62 64 66 68 70 72 74 76
15 18 20 23 26 29 32 34 38 41 43 46 48 51
13 16 18 21 24 27 30 33 36 39 41 44 46 49
11 14 16 19 22 25 28 31 34 37 39 42 44 47
9 12 14 17 20 23 27 30 33 36 38 40 42 44
7 10 12 15 18 21 24 27 30 33 35 38 40 43
- 6 10 13 16 19 21 24 27 30 33 36 38 41
- - 7 10 13 16 19 21 24 27 30 33 36 39
- - - 6 9 12 15 18 21 24 28 31 34 37
- - - - 5 8 12 15 18 21 25 28 31 35
- - - - - - 8 11 15 19 22 26 30 33
- - - - - - 5 9 13 16 20 24 27 31
- - - - - - - 6 10 14 18 22 25 29
- - - - - - - -
- - - - - - - -
- - - - - - - -
- - - - - - - -
MORE or
LESS
Figure 35. HFC−410A Superheat RFC Method
1. Confirm proper airflow across coil using figure 29.
40ºF
2. Compare unit pressures with Table 4, Normal
and
ABOVE
3. Use SUPERHEAT to correctly charge unit or to
4. Set thermostat to call for heat (must have a cooling
5. Connect gauge set.
6. When heat demand is satisfied, set thermostat to
7. Allow temperatures and pressures to stabilize.
8. Measure the suction line pressure and use the use
9. Record suction line temperature:
10. Subtract to determine superheat (SHº):
11. Record the wet bulb temperature (air entering
12. Record outdoor ambient temperature.
13. Compare results with table to the left.
8 12 16 21 24 28
NOTE − Do not attempt to charge system where a
5 9 13 17 22 26
dash appears, system could be overcharged.
- 6 11 15 20 25
Superheat is taken at suction line service port.
- - 8 14 18 24
Suction line superheat must never be less than 5ºF
at the suction line service port.
If value is MORE
than shown, then
ADD refrigerant.
Page 19
Operating Pressures.
verify the charge is correct.
load between 70-80ºF (21−26ºC)
call for cooling.
value to determine saturation temperature (table
5):
SATº =_________
VAPº =_________
VAPº − _____ SATº ______ = SHº______
indoor coil):
WB =_______
If refrigerant is
ADDED, retest to
confirm that unit is
properly charged.
13ACX SERIES