Carrier SINGLE PACKAGE ROOFTOP 48HC - Manual (Page 46)

46
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)
C11161
Fig. 72 -- Outside and Return Air Enthalpy Sensor
Wiring
To wire the return air enthalpy sensor, perform the
following:
1. Use a 2--conductor, 18 or 20 AWG, twisted pair cable
to connect the return air enthalpy sensor to the enthal-
py controller.
2. Connect the field--supplied RED wire to (+) spade
connector on the return air enthalpy sensor and the
(+) terminal on the enthalpy controller. Connect the
BLK wire to (--) spade connector on the return air en-
thalpy sensor and the (--) terminal on the enthalpy
controller.
Smoke Detectors
Smoke detectors are available as factory--installed options
on 48HC models. Smoke detectors 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. The unit is factory--configured
for immediate smoke detector shutdown operation;
additional wiring or modifications to unit terminal board
may be necessary to complete the unit and smoke detector
configuration to meet project requirements.
Return Air Sensor Tube Installation –
The return air sampling tube is shipped in the unit s
supply fan section, attached to the blower housing (see
Fig. 73. Its operating location is in the return air section
of the unit (see Fig. 74, unit without economizer, or
Fig. 75, unit with economizer), inserted into the return air
sensor module housing which protrudes through the back
of the control box.
ROT
ATION
Return Air Sampling Tube
(Shipping Location)
C09102
Fig. 73 -- Typical Supply Air Smoke Detector Sensor
Location
Return Air Detector
Sampling Tube
C09135
Fig. 74 -- Return Air Sampling Tube Location
in Unit without Economizer
Return Air Detector
Sampling Tube
C09136
Fig. 75 -- Return Air Sampling Tube Location
in Unit with Economizer
48H
C