Bryant Preferred 549J 04, Руководство по установке

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versing valve position. Reversing valves are energized during
the cooling stages and the defrost cycle and de-energized
during heating cycles. Once energized at the start of a cooling
stage, the reversing valve will remain energized until the next
heating cycle demand is received. Once de-energized at the
start of a Heating cycle, the reversing valves will remain de-en-
ergized until the next cooling stage is initiated.
Compressor control
The DFB receives inputs indicating Stage 1 Cooling, Stage 2
Cooling and Stage 1 Heating from the space thermostat or unit
control system (RTU Open controller); it generates commands
to start compressors with or without reversing valve operation
to produce Stage 1 Cooling (one compressor runs), Stage 2
Cooling (both compressors run) or Stage 1 Heating (both com-
pressors run).
Fig. 34 — Defrost Control Board Location
NOTES:
1. Jumper for 1-3 seconds: Factory Test — The defrost interval timing
is reduced by a factor of 0.1 seconds/minute based on the posi-
tions of DIP switches SW1 and SW2 (i.e. 90 minutes will be
reduced to 9 seconds).
2. Jumper for 5-20 seconds: Forced Defrost — Defrost runs for
30 seconds if DFT2 is open.
Table 3 — 549J Defrost Board I/O and Jumper Configurations
POINT NAME TYPE OF I/O CONNECTION PIN NUMBER UNIT CONNECTION NOTE
INPUTS
G Fan DI, 24 vac P2-3 CTB-G
Y1 Cool 1 DI, 24 vac P2-5 CTB-Y1
Y2 Cool 2 DI, 24 vac P2-4 CTB-Y2
W1 Heat 1 DI, 24 vac P2-7 CTB-W1
W2 Heat 2 DI, 24 vac P2-6 CTB-W2
R Power 24 vac P3-1 CONTL BRD-8
C Common 24 vac P3-2 CONTL BRD-4
DFT 1 DI, 24 vac DFT-1 to DFT-1 —
DFT 2 DI, 24 vac DFT-2 to DFT-2 —
OUTPUTS
IFO Fan On DO, 24 vac P3-9 REHEAT/HP-2
OF OD Fan On DO, 24 vac OF OFR
RVS1 DO, 24 vac P3-7 to P3-5 — Energize in COOL
RVS2 DO, 24 vac P3-6 to P3-4 — Energize in COOL
COMP 1 DO, 24 vac P3-10 FPT1-REHEAT/HP-6
COMP2 DO, 24 vac P3-8 FPT2-REHEAT/HP-8
HEAT 2 DO, 24 vac E-HEAT TB4-1
COM 24 vac P3-3 TB4-3
CONFIGURATION
Select Jumper 24 vac P1-1 —
2 Compressor 24 vac P1-3 — Use for 549J
SPEED-UP CONFIGURATION
Speed-Up Jumper — JMP17 —
Speed-Up Jumper — JMP18 —