![background image](http://html1.mh-extra.com/html/carrier/50hcq04-12/50hcq04-12_service-and-maintenance-instructions_2561580022.webp)
22
Fig. 35 — Defrost Control Board Location
NOTES:
1. Jumper for 1-3 seconds: Factory Test, defrost runs for 9 seconds.
2. Jumper for 5-20 seconds: Forced Defrost, defrost runs for 30 sec-
onds if DFT2 is open.
Auxiliary (Electric) Heat Control
The 50HCQ unit can be equipped with one or two auxiliary
electric heaters, to provide a second stage of heating. The DFB
will energize this Heating System for a Stage 2 Heating Com-
mand (heaters operate concurrently with compressor(s) in the
Stage 1 Heating cycle), for an Emergency Heating sequence
(compressors are off and only the electric heaters are ener-
gized) and also during the Defrost cycle (to eliminate a “cold
blow” condition in the space).
Defrost
The defrost control mode is a time/temperature sequence.
There are two time components: The continuous run period
and the test/defrost cycle period. The temperature component
is provided by Defrost Thermostat 1 and 2 (DFT1 and DFT2
(D08-D09 only) mounted on the outdoor coil.
The continuous run period is a fixed time period between the end
of the last defrost cycle (or start of the current Heating cycle)
during which no defrost will be permitted. This period can be set
at 30, 60, 90 or 120 minutes by changing the positions of DIP
switches SW1 and SW2 (see Fig. 34 and Table 9). The default
run periods are 60 minutes for unit sizes 04-06, 30 minutes for
unit size 07, 90 minutes for unit sizes 08-09 and 60 minutes for
unit size 12.
Fig. 36 — DIP Switch Settings — Defrost Board
Table 8 — 50HCQ Defrost Board I/O and Jumper Configurations
INPUTS
POINT NAME
TYPE OF I/O
CONNECTION PIN NUMBER
UNIT
CONNECTION
NOTE
G Fan
DI, 24Vac
P2-3
LCTB-G
Y1 Cool 1
DI, 24Vac
P2-5
LCTB-Y1
Y2 Cool 2
DI, 24Vac
P2-4
LCTB-Y2
W1 Heat 1
DI, 24Vac
P2-7
LCTB-W1
W2 Heat 2
DI, 24Vac
P2-6
LCTB-W2
R Power
24Vac
P3-1
CONTL BRD-
8
C Common
24Vac
P3-2
CONTL BRD-4
DFT1
DI, 24Vac
DFT-1 to DFT-1
DFT2
DI, 24Vac
DFT-2 to DFT-2
OUTPUTS
IFO Fan On
DO, 24Vac
P3-9
REHEAT-2
OF OD Fan On
DO, 24Vac
OF
OFR
RVS1
DO, 24Vac
P3-7 to P3-5
Energize in COOL
RVS2
DO, 24Vac
P3-6 to P3-4
Energize in COOL
COMP 1
DO, 24Vac
P3-10
FPT-REHEAT-6
COMP 2
DO, 24Vac
P3-
8
REHEAT-
8
HEAT 2
DO, 24Vac
E-HEAT
HC-1 (TB4-1)
COM
24Vac
P3-3
HC-1 (TB4-3)
CONFIGURATION
Select Jumper
24Vac
P1-1
2 Compressor
24Vac
P1-3
Use for 50HCQD
SPEED-UP
CONFIGURATION
Speed-Up Jumper
JMP17
Speed-Up Jumper
JMP1
8
Summary of Contents for 50HCQ04---12
Page 86: ...86 APPENDIX E WIRING DIAGRAMS cont Fig C 50HCQA04 A05 Control Wiring Diagram 575 3 60...
Page 88: ...88 APPENDIX E WIRING DIAGRAMS cont Fig E 50HCQ 06 Control Wiring Diagram 575 3 60...
Page 93: ...93 APPENDIX E WIRING DIAGRAMS cont Fig J 50HCQ 04 05 06 Power Wiring Diagram 208 230 1 60...
Page 94: ...94 APPENDIX E WIRING DIAGRAMS cont Fig K 50HCQ 04 05 06 Power Wiring Diagram 208 230 3 60...
Page 95: ...95 APPENDIX E WIRING DIAGRAMS cont Fig L 50HCQ 04 05 06 Power Wiring Diagram 460 3 60...
Page 96: ...96 APPENDIX E WIRING DIAGRAMS cont Fig M 50HCQ 04 05 06 Power Wiring Diagram 575 3 60...
Page 100: ...100 APPENDIX E WIRING DIAGRAMS cont Fig Q 50HCQ 12 Power Wiring Diagram 208 230 3 60...
Page 101: ...101 APPENDIX E WIRING DIAGRAMS cont Fig R 50HCQ 12 Power Wiring Diagram 460 3 60 575 3 60...
Page 102: ...102 APPENDIX E WIRING DIAGRAMS cont Fig S 50HCQ PremierLink Control Diagram...
Page 103: ...103 APPENDIX E WIRING DIAGRAMS cont Fig T 50HCQ RTU Open Control Diagram...