Carrier WeatherMaker 48KC Series - Specific Control Features; Outdoor Air Enthalpy Control; Smoke Detectors

40
Outdoor Air Enthalpy Control
(P/N 33CSENTHSW)
The enthalpy control (33CSENTHSW) is available as a
field-installed accessory to be used with the EconoMi$er
®
2
damper system. The outdoor air enthalpy sensor is part of the
enthalpy control. The separate field-installed accessory return
air enthalpy sensor (33CSENTSEN) is required for differen-
tial enthalpy control. See Fig. 54.
Locate the enthalpy control in the economizer next to the
actuator motor. Locate two GRA leads in the factory harness
and connect the gray lead labeled “ESL” to the terminal la-
beled “LOW”. See Fig. 54. Connect the enthalpy control
power input terminals to economizer actuator power leads
RED (connect to 24V) and BLK (connect to GND).
The outdoor enthalpy changeover setpoint is set at the en-
thalpy controller.
Fig. 54 — Enthalpy Switch (33CSENTHSW)
Connections
DIFFERENTIAL ENTHALPY CONTROL
Differential enthalpy control is provided by sensing and com-
paring the outside air and return air enthalpy conditions. In-
stall the outdoor air enthalpy control as described above. Add
and install a return air enthalpy sensor.
RETURN AIR ENTHALPY SENSOR
Mount the return-air enthalpy sensor (33SENTSEN) in the re-
turn-air section of the economizer. The return air sensor is wired
to the enthalpy controller (33CSENTHSW). See Fig. 55.
Fig. 55 — Outside and Return Air Enthalpy
Sensor Wiring
Wiring the Return Air Enthalpy Sensor
1. Use a 2-conductor, 18 or 20 AWG, twisted pair cable to
connect the return air enthalpy sensor to the enthalpy
controller.
2. Connect the field-supplied RED wire to (+) spade con-
nector on the return air enthalpy sensor and the (+) termi-
nal on the enthalpy controller. Connect the BLK wire to
(–) spade connector on the return air enthalpy sensor and
the (–) terminal on the enthalpy controller.
Smoke Detectors
Smoke detectors are available as factory-installed options
on 48KC models. Smoke detectors may be specified for Sup-
ply Air only or for Return Air without or with economizer, or
in combination of Supply Air and Return Air. Return Air
smoke detectors are arranged for vertical return configura-
tions only. All components necessary for operation are facto-
ry-provided and mounted. The unit is factory-configured for
immediate smoke detector shutdown operation; additional
wiring or modifications to unit terminal board may be neces-
sary to complete the unit and smoke detector configuration to
meet project requirements.
Units equipped with factory-optional Return Air smoke
detectors require a relocation of the sensor module at unit in-
stallation. See Fig. 56 for the as-shipped location.
COMPLETING RETURN AIR SMOKE SENSOR
INSTALLATION
1. Unscrew the two screws holding the Return Air Smoke
Detector assembly. See Fig. 57, Step 1. Save the screws.
2. Turn the assembly 90 degrees and then rotate end to end.
Make sure that the elbow fitting is pointing down. See
Fig. 57, Step 2.
3. Screw the sensor and detector plate into its operating
position using screws from Step 1. See Fig. 57, Step 3.
4. Connect the flexible tube on the sampling inlet to the
sampling tube on the basepan.
Fig. 56 — Return Air Smoke Detector,
Shipping Position
ADDITIONAL APPLICATION DATA
Refer to the Application Data sheet titled Factory Installed
Smoke Detectors for Small and Medium Rooftop Units 2 to
25 Tons for discussions on additional control features of these
smoke detectors including multiple unit coordination.
PremierLink™ Controller (Factory Option)
For details on operating 48KC*04-06 units equipped with
the factory-installed PremierLink controller option, refer to
the PremierLink Retrofit Rooftop Controller Version 3.x In-
stallation, Start-Up, and Configuration Installation manual.
RTU Open Controller (Factory-Installed Option)
For details on operating 48KC*04-06 units equipped with
the factory-installed RTU Open controller refer to the
“Factory-Installed RTU Open Multi-Protocol Controller
Control, Start-Up, Operation and Troubleshooting” manual.
7
CTB ECON
(P’LINK: to J4-2) or
(RTU Open: to J2-6)
LOW
GND
24V
Enthalpy
Switch
GRA
BLK
RED
FACTORY WIRING HARNESS
PL6-1 (24-V)
PL6-4 (COM)
GRA
BLK
RED
– 4-20
MAIN
+ VDC
OUT
– 4-20 MAIN
OUT
+ 24-36
VDC IN
LOW
GND
24V
7
PL6-1 (24-V)
PL6-4 (COM)
OUTSIDE AIR
ENTHALPY SWITCH
RETURN AIR
ENTHALPY
SENSOR
CTB ECON
(P’LINK: to J4-2) or
(RTU Open: to J2-6)
RETURN AIR
SMOKE DETECTOR
(AS SHIPPED)