Electrical Controls And Wiring; Refrigerant Circuit; Final Check-Out - Carrier 38TN Service Manual

PRESSURE (PSIG)
AT SERVICE FITTING
80.2
85.1
90.1
95.3
100.6
106.2
112.0
118.0
124.2
130.6
137.2
144.1
151.1
158.4
166.0
173.8
181.8
190.1
198.7
207.5
216.6
226.0
235.7
245.6
Coil fin damage can result in higher operating costs or
compressor damage. Do not use flame, high-pressure water,
steam, volatile or corrosive cleaners on fins or tubing.
2. Clean coil using vacuum cleaner and its crevice tool. Move
crevice tool vertically, close to area being cleaned, making
sure tool touches only the dirt on the fins and not the fins. To
prevent fin damage, do not scrub fins with tool or move tool
horizontally against fins.
3. If oil deposits are present, spray coil with ordinary household
detergent. Wait 10 minutes, and proceed to next step.
4. Using garden hose, spray coil vertically downward with
constant stream of water at moderate pressure. Keep nozzle at
a 15- to 20° angle, about 3 in. from coil face and 18 in. from
tube. Spray so debris is washed out of coil and basepan.
Restore power to unit.
CLEANING OUTDOOR FAN MOTOR AND BLADE
1. Remove fan motor and blade. (See Remove Fan Motor
Assembly in Cabinet section of the manual.) Be careful not to
bend or dent fan blade.
2. Clean motor and blade with soft brush or cloth. Be careful not
to disturb balance weights on fan blade.
3. Check fan blade setscrew for tightness.
4. Reinstall fan motor and blade to top cover and check for
alignment.
5. Reinstall top cover and position blade. (See Fig. 12.)
6. Reconnect electrical power and check for proper operation.

ELECTRICAL CONTROLS AND WIRING

1. Disconnect power to both the outdoor and indoor units.
2. Check all electrical connections for tightness. Tighten all
screws on electrical connections. If any connections appear to
Table 3—Required Liquid Tube Temperatures
REQUIRED SUBCOOLING TEMPERATURE (°F)
0 5
76 71
79 74
82 77
85 80
88 83
91 86
94 89
97 92
100 95
103 98
106 101
109 104
112 107
115 110
118 113
121 116
124 119
127 122
130 125
133 128
136 131
139 134
142 137
145 140
17
10 15
66 61
69 64
72 67
75 70
78 73
81 76
84 79
87 82
90 85
93 88
96 91
99 94
102 97
105 100
108 103
111 106
114 109
117 112
120 115
123 118
126 121
129 124
132 127
135 130
be burned or smokey, disassemble the connection, clean all
parts and stripped wires, and reassemble. Use a new connector
if old one is burned or corroded, and crimp tightly.
3. Reconnect electrical power to the indoor and outdoor units and
observe unit through 1 complete operating cycle.
4. If there are any discrepancies in the operating cycle, trouble-
shoot to find the cause and correct.

REFRIGERANT CIRCUIT

1. Check the refrigerant charge using the superheat or subcooling
method, whichever is applicable, and if low on charge, check
unit for leaks using an electronic leak detector.
2. If any leaks are found, remove and reclaim or isolate charge
(pumpdown) if applicable. Make necessary repairs.
3. Evacuate, recharge, and operate unit through entire cycle.

FINAL CHECK-OUT

After the unit has been operating, the following items should be
checked.
1. Check that the unit operational noise is not excessive due to
vibration of component, tubing, panels, etc. If present, isolate
problem and correct.
2. Check to be sure caps are installed on service valves and are
tight.
3. Check to be sure tools, loose parts, and debris are removed
from the unit.
4. Check to be sure all panels and screws are in place and tight.
Desert and Seacoast Locations
Special consideration must be given to the installation and main-
tenance of condensing units installed in coastal or desert locations.
This is because the salt and alkali content of the sand adheres to the
aluminum fins of the coil and can cause premature coil failure due
to corrosion from salt, alkali, and moisture.
Preventive measures can be taken during installations, such as:
20 25
56 51
59 54
62 57
65 60
68 63
71 66
74 69
77 72
80 75
83 78
86 81
89 84
92 87
95 90
98 93
101 96
104 99
107 102
110 105
113 108
116 111
119 114
122 117
125 120