Field Connections; Temperature Thermistors - Bryant 598B Installation And Start-Up Instructions Manual

TABLE 7—REQUIRED LIQUID-LINE TEMPERATURE (°F)
REQUIRED SUBCOOLING
LIQUID
PRESSURE AT
SERVICE VALVE
(PSIG)
8
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
TABLE 8
TXV TYPE EXPANSION DEVICE
UNIT HIGH CAPACITY ONLY
SUBCOOLING AT SERVICE VALVE
024
036
048
060
2. Keep the outdoor fan operating for 15 minutes,
3. Display the appropriate error code on the status light (see
Table 9),
4. After a 15 minute delay, if Yl or Y2 inputs are on and the
LPS or HPS is reset, energize appropriate compressor
contactor, either low or high.
5. If LPS or HPS has not closed after a 15 minute delay, the
outdoor fan is turned off. If the open switch closes anytime
after the 15 minute delay, then resume operation on call for
Y1 and/or Y2.
J. MAJOR COMPONENTS
TWO-SPEED CONTROL
The two-speed control board controls the following functions:
TEMPERATURE
(°F)
10 12 14 16 18
56 54 52 50 48
58 56 54 52 50
60 58 56 54 52
62 60 58 56 54
64 62 60 58 56
66 64 62 60 58
68 66 64 62 60
70 68 66 64 62
72 70 68 66 64
74 72 70 68 66
76 74 72 70 68
78 76 74 72 70
80 78 76 74 72
82 80 78 76 74
84 82 80 78 76
86 84 82 80 78
88 86 84 82 80
90 88 86 84 82
92 90 88 86 84
94 92 90 88 86
96 94 92 90 88
98 96 94 92 90
100 98 96 94 92
102 100 98 96 94
104 102 100 98 96
106 104 102 100 98
108 106 104 102 100
110 108 106 104 102
112 110 108 106 104
114 112 110 108 106
116 114 112 110 108
118 116 114 112 110
120 118 116 114 112
122 120 118 116 114
124 122 120 118 116
126 124 122 120 118
14°F
15°F
12°F
16°F
TABLE 9—CONTROL FUNCTION LED CODE
CODE
Constant flash
No pause
1 flash
w/pause
2 flashes
w/pause
3 flashes
w/pause
4 flashes
Outdoor coil thermistor failure
w/pause
3 flashes
pause
4 flashes
5 flashes
pause
1 flash
5 flashes
pause
2 flashes
6 flashes
w/pause
Constant light
No pause
No flash
*Function light signal order of importance in case of multiple signal request; 1
is most important.
- Low- and high-compressor contactor operation
- Outdoor fan motor operation
- Crankcase heater operation
- Compressor protection
- Pressure switch monitoring
- Time delays

FIELD CONNECTIONS

The two-speed control received 24vac low-voltage control system
inputs through the screw connections on the left side of the control
board.
TWO-SPEED COMPRESSOR
The two-speed compressor contains motor windings that provide
2-pole (3500 RPM) operation.
COMPRESSOR INTERNAL RELIEF
The compressor is protected by an internal pressure relief (IPR)
which relieves discharge gas into compressor shell when differen-
tial between suction and discharge pressures exceeds 525 psi. The
compressor is also protected by an internal overload attached to
motor windings.
COMPRESSOR CONTROL CONTACTORS
Low and high capacity contactor coils are 24 volts. The electronic
control board controls the operation of the low speed (C-L) and the
high speed (C-H) contactors.
K. TEMPERATURE THERMISTORS
Thermistors are electronic devices which sense temperature. As
the temperature increases, the resistance decreases. Thermistors
are used to sense outdoor ambient and coil temperature. Refer to
Fig. 11 for resistance values versus temperature.
If the outdoor ambient or coil thermistor should fail, a fault code
appears at two-speed control. The crankcase heater is turned on
during all off cycles.
IMPORTANT: Outdoor Air Thermistor Placement
Mount outdoor air thermistor underneath unit base pan lip on
control box side of the unit. Attach to base pan with adhesive tape.
IMPORTANT: If outdoor air thermistor is not properly placed
underneath base pan, unit may see nuisance thermistor out of range
faults.
—16—
DEFINITION
IMPORTANCE*
No demand
Stand by
Low-speed operation
High-speed operation
Outdoor thermistor failure
Thermistor out of range
Low pressure switch trip
High pressure switch trip
Compressor V /V trip
C H
Board failure
SIGNAL
10
9
8
7
6
5
4
3
2
1