59
Minimum heating entering air temperature
When operating on first stage heating, the minimum
temperature of air entering the dimpled heat exchanger is
50
_
F (10
_
C) continuous and 45
_
F (7
_
C) intermittent for
standard heat exchangers and 40
_
F (4
_
C) continuous and
35
_
F (2
_
C) intermittent for stainless steel heat
exchangers. To operate at lower mixed--air temperatures, a
field--supplied outdoor--air thermostat must be used to
initiate both stages of heat when the temperature is below
the minimum required temperature to ensure full fire
operation. Wire the outdoor--air thermostat OALT (part
no. HH22AG106) in series with the second stage gas
valve. (See Fig. 70.) Set the outdoor--air thermostat at
35
_
F (2
_
C) for stainless steel heat exchangers or 45
_
F (7
_
C) for standard heat exchangers. This temperature setting
will bring on the second stage of heat whenever the
ambient temperature is below the thermostat setpoint.
Indoor comfort can be compromised when heating is
initiated using low entering air temperatures with
insufficient heating temperature rise.
LCTB
W2
Thermostat
TH1
TH2
W1
W1
W2
OALT
C08442
Fig. 70 -- OATL Connections
Troubleshooting Heating System
Refer to Table 24 and Table 25 for additional
troubleshooting topics.
48TC
Summary of Contents for 48TC 04 Series
Page 27: ...27 COOLING CHARGING CHARTS cont C14064 Fig 33 Cooling Charging Charts 12 5 Ton 48TC...
Page 29: ...29 COOLING CHARGING CHARTS cont C13218 Fig 35 Charging Chart 48TC Size D16 48TC...
Page 40: ...40 C14052 Fig 51 Typical Smoke Detector System Wiring 48TC...
Page 122: ...122 APPENDIX III WIRING DIAGRAMS C12413 Fig 103 48TC A04 A07 Power Diagram 208 230 1 60 48TC...
Page 124: ...124 APPENDIX III WIRING DIAGRAM LIST C12415 Fig 105 48TC A04 A07 Power Diagram 575 3 60 48TC...
Page 126: ...126 APPENDIX III WIRING DIAGRAM LIST C13246 Fig 107 48TC A08 A12 Power Diagram 575 3 60 48TC...
Page 128: ...128 APPENDIX III WIRING DIAGRAM LIST C13247 Fig 109 48TC D08 D12 Power Diagram 575 3 60 48TC...
Page 130: ...130 APPENDIX III WIRING DIAGRAM LIST C13249 Fig 111 48TC D14 Power Diagram 575 3 60 48TC...
Page 139: ...139 APPENDIX III WIRING DIAGRAMS C12423 Fig 120 48TC D16 Power Diagram 575 3 60 48TC...
Page 143: ...143 APPENDIX III WIRING DIAGRAM LIST C13485 Fig 124 48TC 16 PremierLink Control Diagram 48TC...
Page 145: ...145 APPENDIX III WIRING DIAGRAM LIST C13487 Fig 126 48TC 16 RTU Open Control Diagram 48TC...
Page 146: ...146 APPENDIX III WIRING DIAGRAM LIST C14124 Fig 127 48TC D08 14 E08 14 W7220 2 Speed IFM 48TC...
