Unit Charge; Cooling Only Procedure; Cooling Operation; Status Function Lights - Carrier WEATHERMAKERTM TWO-SPEED 38TDB Installation And Start-Up Instructions Manual

Step 11—Check Charge
Service valve gage ports are not equipped with Schrader
valves. To prevent personal injury, make sure gage manifold
is connected to the valve gage ports before moving valves off
fully back seated position. Wear safety glasses and gloves
when handling refrigerant.

UNIT CHARGE

Factory charge and charging method are shown on pink charging
label. With unit operating, charge Puron® units with liquid using
a commercial type metering device in manifold hose. Charge
refrigerant into suction line.
NOTE: Unit is to be charged in high capacity only. Charging in
low capacity may cause compressor chattering and possible
damage to the compressor.
NOTE: If subcooling charging conditions are not favorable,
charge must be weighed in accordance with unit rating plate ± 0.6
oz/ft of 3/8-in. liquid line above or below 15 ft respectively.
EXAMPLE: To calculate additional charge required for a 25-ft
line set: 25 ft - 15 ft = 10 ft X 0.6 oz/ft = 6 oz of additional charge.

COOLING ONLY PROCEDURE

1. Operate unit a minimum of 15 minutes before checking
charge.
2. Measure liquid service valve pressure by attaching an accurate
gage to service port.
3. Measure liquid line temperature by attaching an accurate
thermistor type or electronic thermometer to liquid line near
outdoor coil.
4. Refer to Table 4 for required subcooling temperature.
5. Refer to Table 3. Find the point where required subcooling
temperature intersects measured liquid service valve pressure.
6. To obtain required subcooling temperature at a specific liquid
line pressure, add refrigerant if liquid line temperature is
higher than indicated or reclaim refrigerant if temperature is
lower. Allow a tolerance of ± 3°F.
.
UNIT CHARGE
Factory charge and charging method are shown on pink charging
label. Puron® refrigerant cylinders contain a dip tube which
allows liquid refrigerant to flow from cylinder in upright
position. Charge Puron units with cylinder in upright position and
a commercial type metering device in manifold hose. Charge
refrigerant into suction line.
NOTE: Unit is to be charged in high capacity only. Charging in
low capacity may cause compressor chattering and possible
damage to the compressor.
NOTE: If subcooling charging conditions are not favorable,
charge must be weighed in accordance with unit rating plate ± 0.6
oz/ft of 3/8-in. liquid line above or below 15 ft respectively.
EXAMPLE: To calculate additional charge required for a 25 ft line
set: 25 ft - 15 ft = 10 ft x 0.6 oz/ft = 6 oz of additional charge.
Step 12—System Functions and Sequence of Operation
The outdoor unit control system has special functions. The
following is an overview of the two-speed control functions:

COOLING OPERATION

This product utilizes a 2-stage cooling indoor thermostat. With a
call for first stage cooling (Yl), the outdoor fan and low capacity
compressor are energized. If low capacity cannot satisfy cooling
demand, high capacity is energized (Yl and Y2 or Y2 only) by the
second stage of indoor thermostat. After second stage is satisfied,
Table 3—Required Liquid-Line Temperature (°F)
LIQUID
PRESSURE AT
SERVICE VALVE
(PSIG)
189 58
195 60
202 62
208 64
215 66
222 68
229 70
236 72
243 74
251 76
259 78
266 80
274 82
283 84
291 86
299 88
308 90
317 92
326 94
335 96
345 98
354 100
364 102
374 104
384 106
395 108
406 110
416 112
427 114
439 116
450 118
462 120
474 122
486 124
499 126
511 128
the unit returns to low-speed operation until first stage is satisfied
or until second stage is required again. When both first stage and
second stage cooling are satisfied, the compressor will shut off.
NOTE: If unit has not operated within the past 12 hr, or following
a unit power-up, upon the next thermostat high- or low-speed
demand, unit operates for a minimum of 5 minutes on high-speed.
NOTE: When two-speed unit is operating at low speed, system
vapor (suction) pressure will be higher than a standard single-
speed system or high-speed operation.
NOTE: Outdoor fan motor will continue to operate for one
minute after compressor shuts off, when outdoor ambient is greater
than or equal to 100°F.

STATUS FUNCTION LIGHTS

A system control STATUS function light is located on the outdoor
unit control board. (See Fig. 12.) The STATUS light provides
indication signals for several system operations. See Table 5 for
codes and definitions. Table 5 also provides the order of signal
importance.
NOTE: Only one code will be displayed on the outdoor unit
control board (the most recent, with the highest priority).
11
REQUIRED SUBCOOLING
TEMPERATURE
(°F)
8 12 14 16 18
56 54 52 50
58 56 54 52404
60 58 56 54
62 60 58 56
64 62 60 58
66 64 62 60
68 66 64 62
70 68 66 64
72 70 68 66
74 72 70 68
76 74 72 70
78 76 74 72
80 78 76 74
82 80 78 76
84 82 80 78
86 84 82 80
88 86 84 82
90 88 86 84
92 90 88 86
94 92 90 88
96 94 92 90
98 96 94 92
100 98 96 94
102 100 98 96
104 102 100 98
106 104 102 100
108 106 104 102
110 108 106 104
112 110 108 106
114 112 110 108
116 114 112 110
118 116 114 112
120 118 116 114
122 120 118 116
124 122 120 118
126 124 122 120
18
48
50
52
54
56
58
60
62
64
66
68
70
72
74
76
78
80
82
84
86
88
90
92
94
96
98
100
102
104
106
108
110
112
114
116
118