Condensate Overflow Switch (Cofs); Field-Installed Accessories; Space Temperature Sensor (T-55); Space Temperature Sensor (T-56) - Carrier 48HC 04-28 Controls, Start-Up, Operation And Troubleshooting

CONDENSATE OVERFLOW SWITCH (COFS)

A separate factory installed device can detect a full drain pan.
This device consists of a pan sensor to detect the water level
and a relay control switch to read the sensor. The control
switch is located in the unit control box and will trip out the
compressors on overflow detection. Since this device is in se-
ries with the compressor contactor and high pressure switch on
any given circuit, ComfortLink does not directly read this. The
relay switch is a normally open device that closes when power
is applied; this allows the compressor to be energized without
problem. If the sensor detects high water levels for 10 seconds
straight, it will open the contact breaking the compressor call.
The switch will also turn its red LED on. If the water level is
low enough for 5 minutes the relay will close again allowing
the compressor call. A blinking red LED on the switch indi-
cates that the sensor has been disconnected.

Field-Installed Accessories

SPACE TEMPERATURE SENSOR (T-55)

The T-55 space temperature sensor (part no. 33ZCT55SPT) is a
field-installed accessory. The sensor is installed on a building
interior wall to measure room air temperature. The T-55 sensor
also includes an override button on the front cover to permit
occupants to override the Unoccupied Schedule (if pro-
grammed). The jumper wire in the installer's packet must be
connected between R and W1 when using a T-55 device.
TB or TB A-SPT+ . . . Sensor Input
TB or TB A-SPT– . . . Sensor Common

SPACE TEMPERATURE SENSOR (T-56)

The T-56 space temperature sensor (part no. 33ZCT56SPT) is a
field-installed accessory. This sensor includes a sliding scale
on the front cover that permits an occupant to adjust the space
temperature set point remotely. The T-56 sensor also includes
an override button on the front cover to allow occupants to
override the unoccupied schedule (if programmed). The jump-
er wire in the installer's packet must be connected between R
and W1 when using a T-56 device.
TB or TB A-SPT+ ... Sensor Input
TB or TB A-SPT– ... Sensor Common
TB or TB A-SPTO ... Setpoint Offset Input

SPACE TEMPERATURE SENSOR (T-58)

The T-58 space temperature sensor (part no. 33ZCT58SPT) is a
field-installed accessory. The T-58 sensor communicates with
the ComfortLink controller, providing space temperature, heat-
ing and cooling set points, and mode operation information.
The jumper wire in the installer's packet must be connected be-
tween R and W1 when using a T-58 device.
Refer to the T-58 installation instructions for information on in-
stalling and configuring the T-58 sensor.
Each T-58 sensor must have a unique address on the CCN.
Each T-58 sensor must also be configured with the address of
the unit control it is communicating to.

SPACE TEMPERATURE SENSOR AVERAGING

See Fig. 40 for space temperature averaging with T-55 sensors
only. If the use of one T-56 sensor is required, refer to Fig. 41.

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 in-
clude Economizer, Power Exhaust, and Electric Heat. Refer to
the Controls Quick Set-Up section for configuration and more
information on these accessories.

TWO-POSITION DAMPER

The two-position outdoor air damper accessory usage depends
on model size and return duct orientation. This accessory wires
directly into the low voltage circuit for the indoor fan control.
No other control configuration is needed. On 04-14 size units a
9 pin to 12 pin converter harness is required and is included in
the kit or factory installed.

INDOOR AIR QUALITY

The indoor air quality (IAQ) sensor (part no. 33ZCSENCO2)
is a field-installed accessory which measures CO
air. When installing this sensor, an ECB board must be in-
stalled and the unit must be configured for IAQ use by setting

Configuration AIR.Q
the Indoor Air Quality section for more information.
TB or TB B-IAQ . . . . . . . . 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)

OUTDOOR AIR QUALITY

The outdoor air quality (OAQ) sensor is a field-installed acces-
sory that measures CO
sensor, an ECB board must be installed and the unit must be
configured for OAQ
 
tion 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 detec-
tors 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
normally open (1) or normally closed (2).
TB or TB A-FDWM . . . . . Discrete Input to Board

FILTER STATUS

The filter status accessory is a field-installed accessory. This
accessory detects plugged filters. When installing this accesso-
ry, the unit must be configured for filter status by setting Con-
 
figuration 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. Refer to the Filter Acces-
sory installation instructions for more information.

FAN STATUS

The fan status accessory is a field-installed accessory. This ac-
cessory detects when the indoor fan is blowing air. When in-
stalling this accessory, the unit must be configured for fan sta-
tus by setting Configuration
open (1) or normally closed (2). Normally open (1) is the pre-
ferred configuration.
Fan status wires are pre-run in the unit harness and located near
the switch installation location. Refer to the Fan Accessory in-
stallation instructions for more information.
86
2

IA.CF to a value of 1, 2, or 3. See
levels in the air. When installing this
2
use by setting

UNIT
 
UNIT FN.SW to normally
levels in the
Configura-

FS.SW to