A caution – Carrier 38QRA User Manual
Page 6
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6. Using Table 4, find air temperature entering outdoor coil and
wet-bulb temperature entering indoor coil. At this intersection
note the superheat.
A CAUTION
To prevent personal injury, wear safety glasses and gloves
when handling refrigerant. Do not overcharge system. This
can cause compressor flooding.
Table 5—Required Suction Tube Temperature (F)
(Entering Suction Service Valve)
A CAUTION
Service valves must be fully back seated to close service port.
There is no Schrader valve at the service port and failure to
back seat the valve could result in loss of system charge or
personal injury.
7. Using Table 5, find superheat temperature and suction pres
sure; note suction line temperature.
8. If unit has higher suction line temperature than charted
temperature, add refrigerant until charted temperature is
reached (+/- 3 F).
9. If unit has lower suction line temperature than charted
temperature, bleed refrigerant until charted temperature is
reached (+/- 3 F).
10. If air temperature entering outdoor coil or pressure at suction
valve changes, charge to new suction line temperature indi
cated in chart.
11. This procedure is valid, independent of indoor air quantity.
TEMP(F)
61.5
64.2
67.1
70.0
73.0
76.0
79.2
82.4
85.7
0
35
37
39
41
43
45
47
49
51
2
37
39
41
43
45
47
49
51
53
4
39
41
43
45
47
49
51
53
55
6
41
43
45
47
49
51
53
55
57
8
43
45
47
49
'51
53
55
57
59
10
45
47
49
51
53
55
57
59
61
12
47
49
51
53
55
57
, 59
61
63
14
49
51
53
55
57
59
61
63
65
16
51
53
55
57
59
61
63
65
67
18
53
55
57
59
61
63
65
67
69
20
55
57
59
61
63
65
67
69
71
22
57
59
61
63
65
67
69
71
73
24
59
61
63
65
67
69
71
73
75
26
61
63
65
67
69
71
73
75
77
28
63
65
67
69
71
73
75
77
79
30
65
67
69
71
73
75
77
79
81
32
67
69
71
73
75
77
79
81
83
34
69
71
73
75
77
79
81
83
85
36
71
73
75
77
79
81
83
85 .
87
38
73
75
77
79
81
83
85
87
89
40
75
77
79
81
83
85
87
89
91
Heating
To check system operation during heating cycle, use Table 6. This
table indicates whether a correct relationship exists between
system operating pressure and air temperatures entering indoor and
outdoor units. In heating mode, check should be made approxi
mately 15 minutes after defrost with unit running with a clean coil.
If pressure and temperature do not match on chart, system
refrigerant charge may not be correct or other system abnormali
ties may exist. Do not use table to adjust refrigerant charge.
When recharging is necessary during heating season, weigh in total
charge as indicated in Table 2. Remove or recycle any refrigerant
remaining in system before recharging. If the system has lost
complete charge, evacuate and recharge by weight. Service port
connections are provided on liquid- and suction-line service
valves. For evacuation and recharging, Dial-a-Charge charging
cylinder, or similar device, is an accurate device for recharging
system by weight.
CARE AND MAINTENANCE
For continuing high performance, and to minimize possible
equipment failure, it is essential that periodic maintenance be
performed on this equipment. Consult your servicing contractor or
users manual for the proper frequency of maintenance. Frequency
of maintenance may vary depending upon geographic areas, such
as coastal applications.