34
Table 8 – Detector Indicators
CONTROL OR INDICATOR
DESCRIPTION
Magnetic test/reset switch
Resets the sensor when it is in the alarm or trouble state. Activates or tests the sensor when it is in
the normal state.
Alarm LED
Indicates the sensor is in the alarm state.
Trouble LED
Indicates the sensor is in the trouble state.
Dirty LED
Indicates the amount of environmental compensation used by the sensor
(flashing continuously = 100%)
Power LED
Indicates the sensor is energized.
Condenser Fan Motor Protection
The condenser fan motor is internally protected against
over--temperature.
Relief Device
A soft solder joint at the suction service access port
provides pressure relief under abnormal temperature and
pressure conditions (i.e., fire in building). Protect this
joint during brazing operations near this joint.
Control Circuit, 24--V
The control circuit is protected against overcurrent
conditions by a circuit breaker mounted on control
transformer TRAN. Reset is manual.
GAS HEATING SYSTEM
General
The heat exchanger system consists of a gas valve feeding
multiple in--shot burners off a manifold. The burners fire
into matching primary tubes. The primary tubes discharge
into combustion plenum where gas flow converges into
secondary tubes. The secondary tubes exit into the
induced draft fan wheel inlet. The induced fan wheel
discharges into a flue passage and flue gases exit out a
flue hood on the side of the unit. The induced draft fan
motor includes a Hall Effect sensor circuit that confirms
adequate wheel speed through the Integrated Gas Control
(IGC) board. Safety switches include a Rollout Switch (at
the top of the burner compartment) and a limit switch
(mounted through the fan deck, over the tubes). (See Fig.
45 and Fig. 46.)
INDUCED-
DRAFT
MOTOR
MOUNTING
PLATE
INDUCED-
DRAFT
MOTOR
MANIFOLD
PRESSURE
TAP
VESTIBULE
PLATE
FLUE
EXHAUST
ROLLOUT
SWITCH
BLOWER
HOUSING
GAS
VALVE
BURNER
SECTION
C06152
Fig. 45 -- Burner Section Details
Limit Switch
for Sideshot
Limit Switch
for Downshot
C10336
Fig. 46 -- Limit Switch Location
Fuel Types and Pressures
Natural Gas
The 48HC unit is factory--equipped for use with Natural
Gas fuel at elevation under 2000 ft (610 m). See section
Orifice Replacement for information in modifying this
unit for installation at elevations above 2000 ft (610 m).
Gas line pressure entering the unit’s main gas valve must
be within specified ranges. Adjust unit gas regulator valve
as required or consult local gas utility.
Table 9 – Natural Gas Supply Line Pressure Ranges
UNIT MODEL
UNIT SIZE
MIN
MAX
48HC
All
4.0 in. wg
(996 Pa)
13.0 in. wg
(3240 Pa)
Manifold pressure is factory--adjusted for NG fuel use.
Adjust as required to obtain best flame characteristic.
Table 10 – Natural Gas Manifold Pressure Ranges
UNIT
MODEL
UNIT
SIZE
HIGH
FIRE
LOW
FIRE
RANGE
48HC
All
3.5 in. wg
(872 Pa)
1.7 in. wg
(423 Pa)
{
2.0---5.0 in. wg (Hi)
(498---1245 Pa)
48HC
Low NOx
All
3.5 in. wg
(872 Pa)
NA
2.0---5.0 in. wg (Hi)
(498---1245 Pa)
NA: Not Available
{
3 Phase models only
Liquid Propane
Accessory packages are available for field--installation
that will convert the 48HC unit (except low NOx model)
48H
C
Summary of Contents for 48HC*04-14
Page 94: ...94 APPENDIX IV WIRING DIAGRAMS C14007 Fig 80 48HC A04 A06 YAC Power Diagram 230 1 60 48HC ...
Page 96: ...96 APPENDIX IV WIRING DIAGRAMS C14013 Fig 82 48HC A04 A06 YAC Power Diagram 575 3 60 48HC ...
Page 97: ...97 APPENDIX IV WIRING DIAGRAMS C14018 48HC ...
Page 98: ...98 APPENDIX IV WIRING DIAGRAMS C14019 48HC ...
Page 99: ...99 APPENDIX IV WIRING DIAGRAMS C13484 Fig 83 48HC D08 D09 YAC Power Diagram 230 460 3 60 48HC ...
Page 100: ...100 APPENDIX IV WIRING DIAGRAMS C14024 Fig 84 48HC D08 D09 YAC Power Diagram 575 3 60 48HC ...
Page 101: ...101 APPENDIX IV WIRING DIAGRAMS C14027 Fig 85 48HC D12 YAC Power Diagram 230 460 3 60 48HC ...
Page 102: ...102 APPENDIX IV WIRING DIAGRAMS C14029 Fig 86 48HC D12 YAC Power Diagram 575 3 60 48HC ...
Page 104: ...104 APPENDIX IV WIRING DIAGRAMS C14032 Fig 88 48HC D14 YAC Power Diagram 230 460 3 60 48HC ...
Page 105: ...105 APPENDIX IV WIRING DIAGRAMS C12462 Fig 89 48HC D14 YAC Power Diagram 575 3 60 48HC ...
Page 123: ...123 APPENDIX IV WIRING DIAGRAMS C12690 Fig 107 PremierLink System Control Wiring Diagram 48HC ...
Page 125: ...125 APPENDIX IV WIRING DIAGRAMS C14034 Fig 109 RTU Open Wiring Diagram 48HC ...