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SMOKE DETECTOR
The units can be equipped with an accessory smoke detector
located in the supply or return air. The detector is wired to the
Comfort
Link controls and, if activated, will stop the unit by
means of a special fire mode. The smoke detector can also be
wired to an external alarm system through TB201 terminals 1
and 2. The sensor is located in the supply or return air sections.
FILTER STATUS SWITCH
The units can be equipped with optional accessory filter status
switch on both the return and supply (post) air filters. The
switch measures the pressure drop across the filters and closes
when an adjustable pressure set point is exceeded. The sensors
are located in the control panel. The return filter switch is con
-
nected to terminals 1 and 2 on TB203. The 180-ohm resistor is
on the terminals for when the filter pressure is used. The resis
-
tor must be removed for the switch to operate properly. The
supply filter switch is connected to terminals 3 and 4 on
TB203. The 180-ohm resistor must be removed.
FILTER PRESSURE SENSOR
The units can be equipped with optional accessory filter pres
-
sure sensors on both the return and supply (post) air filters. The
sensor measures the pressure drop across the filters and outputs
a 4 to 20 mA signal that is read by the
Comfort
Link controls.
The sensors are located in the control panel. The return filter
sensor is connected to terminals 1 and 2 on TB203. The supply
filter sensor is connected to terminals 3 and 4 on TB203. The
180-ohm resistor is on the terminals for when the filter pres
-
sure sensors are used. The resistors must remain for the sensors
to operate properly.
NOTE:
Comfort
Link controls can accept either the filter status
switch OR the filter pressure sensor. It cannot accept both at
the same time.
FAN STATUS SWITCH
The units can be equipped with an optional fan status switch
that will monitor the pressure rise across the indoor fans.
RETURN AIR CO
2
SENSOR
The unit can be equipped with a return air IAQ CO
2
sensor that is
used for the demand controlled ventilation. The sensor is located
in the return air section and can be accessed from the filter access
door.
BOARD ADDRESSES
Each board in the system has an address. The MBB has a de
-
fault address of 1 but it does have an instance jumper that
should be set to 1 as shown in Fig. 32. For the other boards in
the system there is a 4-dip switch header on each board that
should be set as shown below.
0 = On; 1 = Off
Accessory Control Components
In addition to the factory-installed options, the units can also
be equipped with several field-installed accessories that ex
-
pand the control features of the unit. The following hardware
components can be used as accessories.
ROOM THERMOSTATS
The
Comfort
Link controls support a conventional electro-me
-
chanical or electronic thermostat that uses the Y1, Y2, W1,
W2, and G signals. The control also supports an additional in
-
put for an occupied/unoccupied command that is available on
some thermostats. The
Comfort
Link controls can be configured
to run with up to 6 stages of capacity. The room thermostat is
connected to TB201.
The
Comfort
Link controls also support the use of space tem
-
perature sensors and can be used with the T55 and T56 sensors.
The controls can also be used with CCN communicating T58
room sensor. The T55 and T56 sensors are connected to TB201
terminals 1, 2, and 3. The T58 sensor is connected to the CCN
connections on COMM board. Whenever a unit equipped with
heat is operated without a thermostat, the user must install the
red jumpers from R to W1, and W2 on TB201 for the heat
function to work correctly.
BOARD
SW1
SW2
SW3
SW4
RXB
0
0
0
0
EXB
1
0
0
0
SCB
0
0
0
0
CEM
0
0
0
0
EXV-A
1
0
0
0
EXV-B
0
1
0
0
EXV-C
0
0
0
0
RXB-E
0
1
0
0
Summary of Contents for WeatherExpert 48N2
Page 135: ...135 Fig 18 48 50N Typical Power Schematic Nominal 075 Ton Unit Shown ...
Page 136: ...136 Fig 19 48 50N Typical Power Schematic Nominal Ton 90 150 Units Shown ...
Page 137: ...137 Fig 20 48 50N Main Base Board Input Output Connections ...
Page 138: ...138 Fig 21 48 50N RXB EXB CEM Input Output Connections a48 9307 ...
Page 139: ...139 Fig 22 48 50N EXV SCB Input Output Connections a48 9308 ...
Page 140: ...140 Fig 23 48N Typical Modulating Gas Heat Unit Control Wiring ...
Page 141: ...141 Fig 24 50N Typical Electric Heat Unit Control Wiring ...
Page 144: ...144 Fig 27 48N Typical Gas Heat Section Wiring Nominal Ton 120 to 150 Units ...
Page 145: ...145 Fig 28 48 50N Typical Power Component Control Wiring 460 v ...
Page 146: ...146 Fig 29 48 50N Component Control Wiring 575 v Nominal Ton 075 to 150 Units ...
Page 147: ...147 Fig 30 48 50N Component Arrangement Power Box ...
Page 148: ...148 Fig 31 48 50N Component Arrangement Control Box ...
Page 240: ...240 APPENDIX D VFD INFORMATION CONT Fig G VFD Bypass Wiring Diagram WHEN USED ...