Carrier 48TC 17 Series Service And Maintenance Instructions page 30

Return Air without Economizer
The sampling tube is located across the return air opening
on the unit basepan. See Fig. 38. The holes in the
sampling tube face downward, into the return air stream.
The sampling tube is attached to the control module
bushing that extends from the control box through the
partition into the return air section of the unit. The sensor
tube is shipped mounted to the Indoor Blower Housing
and must be relocated to the return air section of the unit.
Installation requires that this sensing tube be attached to
the control module bushing. See installation steps.
*RA detector must be moved from shipping
position to operating position by installer
Fig. 38 − Typical Return Air Detector Location
Return Air with Economizer
The sampling tube is inserted through the side plates of
the economizer housing, placing it across the return air
opening on the unit basepan. See Fig. 39. The holes in the
sampling tube face downward, into the return air stream.
The sampling tube is connected through tubing to the
return air sensor that is mounted on a bracket high on the
partition between return filter and controller location. The
Return Air Sensor is shipped in a flat−mounting location.
Installation requires that this sensor be relocated to its
operating location and the tubing to the sampling tube be
connected. See installation steps.
RETURN AIR
DETECTOR MODULE
(Shipping position
shown)*
CONTROLLER
MODULE
RETURN AIR DETECTOR
SAMPLING TUBE
C07307
FIOP Smoke Detector Wiring and Response
All units: The FIOP smoke detector is configured to
automatically shut down all unit operations when a smoke
condition is detected. See Fig. 40, Smoke Detector
Wiring.
Highlight A: The JMP 3 is factory−cut, transferring unit
control to the smoke detector.
Highlight B: The smoke detector NC contact set will
open on a smoke alarm condition, de−energizing the ORN
conductor.
Highlight C: 24V power signal using the ORN lead is
removed at the Smoke Detector input on the Central
Terminal board (CTB); all unit operations cease
immediately.
PremierLinkt and RTU−−Open Controls: Unit operating
functions (fan, cooling and heating) are terminated as
described above. In addition:
Highlight D: On smoke alarm condition, the smoke
detector NO Alarm contact will close, supplying 24V
power to the GRA conductor.
Highlight E: The GRA lead at the Smoke Alarm input
on LCTB provides a 24V signal to the FIOP DDC
control.
PremierLink: This signal is conveyed to PremierLink
FIOP's TB1 at terminal TB1−6 (BLU lead). This signal
initiates the FSD sequence by the PremierLink control.
FSD status is reported to the connected CCN network.
RTU−OPEN: The 24V signal is conveyed to the
RTU−OPEN J1−10 input terminal. This signal initiates the
FSD sequence by the RTU−OPEN control. FSD status is
reported to the connected BAS network.
Using Remote Logic: Five field−use conductors are
provided for additional annunciation functions.
Additional Application Data: Refer to Catalog number
HKRNKA−1XA for discussions on additional control
features of these smoke detectors, including multiple unit
coordination.
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