Carrier 48LC 04 Controls, Start-Up, Operation And Troubleshooting page 65

Carrier Accessory Kits
There are specific accessory kits sold for various field installed
accessories. These kits vary based on model, size, voltage,
manufacture date, and duct orientation. Some of these kits include
Economizer, Power Exhaust, and Electric Heat.
Controls Quick Set- -Up section for configuration and more
information on these accessories.
Indoor Air Quality
The indoor air quality (IAQ) sensor (part no. 33ZCSENCO2) is a
field-installed accessory which measures CO
When installing this sensor, an ECB board must be installed and
the unit must be configured for IAQ use by setting
ConfigurationAIR.QIA.CF to a value of 1, 2, or 3. See the
Indoor Air Quality section for more information.
TB or IAQ . . . . . . . . . . . . . 4- -20mA Input
TB or COM . . . . . . . . . . . . Sensor Common
TB or R- -2 . . . . . . . . . . . . . . 24vac Output
TB or C- -2 . . . . . . . . . . . . . . Common (GND)
Outdoor Air Quality
The outdoor air quality (OAQ) sensor is a field-installed accessory
that measures CO levels in the air. When installing this sensor, an
2
ECB board must be installed and the unit must be configured for
OAQ use by setting ConfigurationAIR.QOA.CF to a value
of 1 or 2. See the Indoor Air Quality section for more information.
TB or TB B- -SARH . . . . . . 4- -20mA Input
TB or TB B- -COM Sensor Common
TB or TB B- -R- -2 24vac Output
TB or TB B- -C- -2 Common (GND)
Smoke Detectors
The smoke detectors are field-installed accessories. These detectors
can detect smoke in either the return air or supply and return air.
When installing either detector, the unit must be configured for fire
shutdown by setting ConfigurationUNITFS.SW to normally
open (1) or normally closed (2).
TB or FDWM . . . Discrete Input to Board
Filter Status
The filter status accessory is a field-installed accessory. This
accessory detects plugged filters. When installing this accessory,
the unit must be configured for filter status by setting
ConfigurationUNITFL.SW to normally open (1) or normally
closed (2). Normally open (1) is the preferred configuration.
Filter status wires are pre- -run in the unit harness and located near
the switch installation location.
installation instructions for more information.
Fan Status
The fan status accessory is a field-installed accessory. This
accessory detects when the indoor fan is blowing air. When
installing this accessory, the unit must be configured for fan
status by setting ConfigurationUNITFN.SW to normally
open (1) or normally closed (2). Normally open (1) is the
preferred configuration.
Fan status wires are pre- -run in the unit harness and located near the
switch installation location. Refer to the Fan Accessory installation
instructions for more information.
Refer to the
levels in the air.
2
Refer to the Filter Accessory
Enthalpy Sensors
The enthalpy accessories are field-installed accessories. The first
accessory (outdoor air only) determines when the enthalpy is low
relative to a fixed reference. Adding the second accessory (return
air) compares the enthalpy between the outdoor and return
airstreams. In each case, the enthalpy 4 to 20 mA signals are
converted to a switch output which is read by the ECB. When
installing this accessory, the unit must be configured for
enthalpy-based control by setting ConfigurationECONEN.SW
to normally open (1). See Fig. 11 and Fig. 12 for wiring details.
Normal status is an active switch which tells the control that
enthalpy is LOW. The actual switch terminal LOW is normally
closed. Refer to the Enthalpy Kit installation instructions for more
information on the installation.
Return/Supply Air Temperature Sensor
The temperature sensor (part no. 33ZCSENSAT) is a field-installed
accessory which may be installed on the common return air duct
and/or the common supply air duct near the unit. The duct return
air temperature (RAT) may be used to replace the RAT sensor that
is inside the unit's return air section. The duct supply air
temperature (SAT) may be used to replace the SAT sensor that is
internal to the unit. A supply duct SAT measurement is valid for
heating mode display while the factory-standard internal SAT is
not valid for heating due to its location upstream of the heating
section. When installing the supply duct SAT, the unit must be
configured by setting ConfigurationUNITSAT.H to ENBL.
A SAT sensor in the supply duct is the preferred configuration for
systems with Carrier variable volume and temperature (VVT)
accessory controls.
The field connection terminal board has SAT and RAT terminals.
When installing field sensors, use these terminals accordingly to
connect into the MBB.
IMPORTANT: When wiring a field SAT sensor, the factory
installed on must be disconnected from the back of the terminal
board.
Space Humidistat
The Space Humidistat (part no. - -- -HL- -- -38MG- -029) is a wall
mounted device with an adjustable setpoint to control humidity
levels. The humidistat input is provided on the field connection
terminal board. The Space Humidity Switch configuration,
ConfigurationUNITRH.SW, identifies the normally open or
normally closed status of this input at LOW humidity.
TB or HUM . . . . . . . . . . . . Discrete Input to Board
TB or TR- -2 . . . . . . . . . . . .
NOTE: The humidistat terminals are only in use when the unit is
equipped with the Humidi- -MiZer factory option.
Space Humidity Sensor
The space relative humidity sensor (part no. 33ZCSENDRH- -01
duct mount or 33ZCSENSRH- -01 wall mount) is a field- -installed
accessory. The space relative humidity (RHS) may be selected for
use if the outdoor air quality sensor (OAQ) is not used and an
economizer board is installed. When installing the relative
humidity sensor, the unit must be configured by setting
ConfigurationUNITRH.S to YES.
TB or LPWR . . . . . . . . . . .
TB or SPRH . . . . . . . . . . . .
65
24 VAC Dry Contact Source
24 VDC Loop Power
4- -20mA Input Signal