Carrier 38BYC Installation And Start-Up Instructions Manual page 7

CES0110063,
CES0130024
Tab{e 3--Defrost Control Speedup-
A91444
SPEEDUP
PARAMETER
(NOMINAL)
30=minute cycle 7 sec
50=minute cycle 12 sec
90=minute cycle 21 sec
t0=minute cycle 2 sec
8 minutes 1 sec
Timing Sequence
MBNIMUN MAXIMUM
(MRNUTE$} (MINUTES)
27 33
45 55
81 99
9 11
4.5 5.5
Fig. 10--Defrost Control
6. When you hear reversing valve change position, remove
screwdriver immediately; othep.vise, control will tem_inate
nom_al 10=minute defrost cycle in approximately 2 sec.
NOTE: Length of defiost cycle is dependent upon length of time
it takes to remove screw&iver fiom test pins aker reversing valve
has shire&
7. Unit will remain in defrost for remainder of defrost-cycle time
or until defrost thermostat reopens at approximately 80°F coil
temperature of liquid line.
8. Turn off power to outdoor unit and reconnect _hn motor lead
to OF2 on control board. (See Fig. 10.)
Step 14--Check Charge
Factory charge is shown on unit rating plate. To check charge in
cooling mode. ret'cr to Cooling Only Procedure. To check charge
in heating mode, refer to Heating Check (7hart Procedure.
COOLING=ONLY PROCEDL RE
NOTE: If superheat= or subcooling=charging conditions are not
favorable, charge must be weighed in accordance with unit rating
plate ÷ 0.6 ozi['t of 3/8-in. liquid line above or below 15 ft
respectively
EXAMPLE:
To calculate additional charge required for a 25 k line set:
25 ft 15 ft 10 ft X 06 ozi[_ 6 oz of additional charge
Units installed with cooling mode TXV require charging with the
subcooling method.
1 Operate unit a minimum of 10 minutes befbre 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 electlonic them_ometer to liquid line near
outdoor coil.
4. Refkr to unit rating plate for required subcooting temperature.
5. Refkr to Table 4. 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 d-_an indicated or reclaim refrigerant if temperature is
lower. Allow a tolerance of ÷ 3_T.
TaNe 4--Required Liquid=Line Temperature (°F)
LIQUID
PRESSURE AT
SERVICE VALVE
(PSIG)
134
t41
148
186
163
t71
t79
187
19G
205
214
223
233
243
253
264
274
288
297
309
321
331
346
389
REQUIRED SUBCOOLING
TEMPERATURE (°F)
5 10 15 20
71 66 61 56
74 69 64 59
77 72 67 62
80 75 70 65
83 78 73 68
86 81 76 71
89 84 79 74
92 87 82 77
95 90 85 80
98 93 88 83
101 96 91 86
104 99 94 89
107 102 97 92
110 105 100 95
113 108 103 98
116 111 106 101
119 114 109 104
122 117 112 107
125 120 115 110
128 123 118 113
131 126 121 116
134 129 124 119
137 132 127 122
140 135 130 125
HEATING CHE(K CHAR7 PROCEDURE
To check system operation dtlring heating cycle, refer to the
Heating Check (;hart on outdoor unit This chart indicates whether
a correct relationship exists between system operating pressure and
air temperature entering indoor and outdoor units. If pressure and
temperature do not match on chart, system ret'rigerant charge may
not be con'ect. Do not use chart to adjust refrigerant charge.