Smoke Detectors - Carrier WeatherMaster 48HC14 Installation Instructions Manual

DIFFERENTIAL ENTHALPY CONTROL — Differential
enthalpy control is provided by sensing and comparing the out-
side air and return air enthalpy conditions. Install the outdoor
air enthalpy control as described above. Add and install a re-
turn air enthalpy sensor.
RETURN AIR ENTHALPY SENSOR — Mount the return-
air enthalpy sensor (33CSENTSEN) in the return-air section of
the economizer. The return air sensor is wired to the enthalpy
controller (33CSENTHSW). See Fig. 96.
24V
– 4-20
MAIN
GND
+ VDC
OUT
LOW
OUTSIDE AIR
ENTHALPY SWITCH
+ 24-36
VDC IN
– 4-20 MAIN
OUT
Fig. 96 — Outside and Return Air Enthalpy Sensor
Wiring
To wire the return air enthalpy sensor, perform the follow-
ing:
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 are available as
Smoke Detectors —
factory-installed options on 48HC**14 models. Smoke detec-
tors may be specified for Supply 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 configurations only. All components necessary
for operation are factory-provided and mounted. The unit is
factory-configured for immediate smoke detector shutdown
operation; additional wiring or modifications to unit terminal
STEP 1
RED PL6-1 (24-V)
BLK PL6-4 (COM)
CTB ECON
GRA 7
(P'LINK: to J4-2) or
(RTU Open: to J2-6)
RETURN AIR
ENTHALPY
SENSOR
Fig. 98 — Completing Installation of Return Air Smoke Sensor
board may be necessary to complete the unit and smoke detec-
tor configuration to meet project requirements.
Units equipped with factory-optional Return Air smoke de-
tectors require a relocation of the sensor module at unit installa-
tion. See Fig. 97 for the as shipped location.
Completing Installation of Return Air Smoke Sensor:
1. Unscrew the two screws holding the Return Air Smoke
Detector assembly. See Fig. 98, Step 1. Save the screws.
2. Turn the assembly 90 and then rotate end to end. Make
sure that the elbow fitting is pointing down. See Fig. 98,
Step 2.
3. Screw the sensor and detector plate into its operating po-
sition using screws from Step 1. See Fig. 98, Step 3.
4. Connect the flexible tube on the sampling inlet to the
sampling tube on the basepan.
RETURN AIR
SMOKE DETECTOR
(AS SHIPPED)
Fig. 97 — Return Air Smoke Detector, Shipping
ADDITIONAL APPLICATION DATA — Refer to the Ap-
plication Data sheet titled Factory Installed Smoke Detectors
for Small and Medium Rooftop Units 2 to 25 Tons for discus-
sions on additional control features of these smoke detectors
including multiple unit coordination.
STEP 2
63
Position
STEP 3