150
Factory-Installed Components
MAIN BASE BOARD (MBB)
See Fig 32. The MBB is the center of the
Comfort
Link control
system. The MBB contains the major portion of the operating
software and controls the operation of the unit. The MBB has
22 inputs and 11 outputs. See Table 94 for the inputs and out
-
put assignments. The MBB also continuously monitors addi
-
tional data from the EXB, EXV, RXB, SCB, and CEM boards,
as well as the VFDs through the LEN communications port.
The MBB also interfaces with the Carrier Comfort Network
®
system through the CCN communications port located on the
COMM3 board. The COMM3 board has permanent terminals
as well as a J11 jack for temporary connections. The board is
located in the control box.
ROOFTOP CONTROL BOARD (RXB)
The RXB communicates with and controls the damper actua
-
tors, hydronic, and humidifier valves. The RXB has additional
inputs and outputs required for the control of the unit. All units
have an RXB board. See Fig. 33. The board has 9 inputs and 8
outputs. Details can be found in Table 95. The RXB board is
located in the control box.
ECONOMIZER CONTROL BOARD (EXB)
The EXB is used on units with options including return fan, digital
scroll compressor, VFD with bypass, low ambient or accessory
humidifier. See Fig. 33. The board has inputs to sense the return
fan cfm and supply fan cfm. This board is located in the control
box. Input and output assignments are summarized in Table 96.
STAGED GAS HEAT BOARD (SCB)
When optional modulating gas heat is used, the SCB board is in
-
stalled and controls additional stages of gas heat. See Fig. 34. The
SCB also provides additional sensors for monitoring of the sup
-
ply-air and limit switch temperatures. For units equipped with
modulating gas heat, the SCB provides the 4 to 20 mA signal to
the SC30 board that sets the modulating gas section capacity. The
SCB is also used for the optional SCR electric heat or prognostics.
This board is located in the control box. The inputs and outputs are
summarized in Table 97.
CONTROL EXPANSION MODULE (CEM)
The optional CEM is used to provide inputs for demand limiting,
remote set point and other optional inputs typically needed for en
-
ergy management systems. See Fig. 35. On CCN systems, these
inputs can be interfaced to through the CCN communications. It is
located in the main control box. The CEM also has inputs for ac
-
cessory relative humidity sensors. This board is also used on units
equipped with optional outdoor air CFM monitoring. The inputs
and outputs are summarized in Table 98.
The optional (or accessory) CEM is used to accept inputs for
additional sensors or control sequence switches, including:
• Smoke control mode field switches
• VAV supply air set point reset using an external 4 to 20 mA
signal
• Outdoor air CO
2
sensor
• Space, return and/or outdoor air relative humidity sensors
• IAQ function discrete switch
• Air filter monitoring switches and transducers
• Demand limit sequence proportional signals or discrete
switches
The CEM is factory-installed when the outdoor air cfm control
option is installed.
Содержание WeatherExpert 48N2
Страница 135: ...135 Fig 18 48 50N Typical Power Schematic Nominal 075 Ton Unit Shown ...
Страница 136: ...136 Fig 19 48 50N Typical Power Schematic Nominal Ton 90 150 Units Shown ...
Страница 137: ...137 Fig 20 48 50N Main Base Board Input Output Connections ...
Страница 138: ...138 Fig 21 48 50N RXB EXB CEM Input Output Connections a48 9307 ...
Страница 139: ...139 Fig 22 48 50N EXV SCB Input Output Connections a48 9308 ...
Страница 140: ...140 Fig 23 48N Typical Modulating Gas Heat Unit Control Wiring ...
Страница 141: ...141 Fig 24 50N Typical Electric Heat Unit Control Wiring ...
Страница 144: ...144 Fig 27 48N Typical Gas Heat Section Wiring Nominal Ton 120 to 150 Units ...
Страница 145: ...145 Fig 28 48 50N Typical Power Component Control Wiring 460 v ...
Страница 146: ...146 Fig 29 48 50N Component Control Wiring 575 v Nominal Ton 075 to 150 Units ...
Страница 147: ...147 Fig 30 48 50N Component Arrangement Power Box ...
Страница 148: ...148 Fig 31 48 50N Component Arrangement Control Box ...
Страница 168: ...168 Fig 47 Sensor and Ignition Position Fig 48 Combustion Blower Details SENSOR DETAILS IGNITION DETAILS ...
Страница 240: ...240 APPENDIX D VFD INFORMATION CONT Fig G VFD Bypass Wiring Diagram WHEN USED ...