Carrier 40UV Installation, Start-Up And Service Instructions Manual page 31

The LLR is designed to trip if any 1-ft section of the capital-
ly tube senses cold air below the LLR set point. The tempera-
ture must exceed 33 F for the LLR to automatically reset to
restore normal operations.
SPACE TEMPERATURE SENSOR (Factory-Installed
Option) — The space temperature sensor is used to measure
the building interior temperature. See Fig. 16.
The sensor is shipped with the unit, factory-wired
and factory-mounted in the control swing panel inside the left
hand compartment.
If remote temperature sensing is required, then the sensor
may be removed and mounted on an internal wall where
temperature sensed is representative of the entire zone to be
serviced by the unit. The sensor wall plate accommodates the
National Electrical Manufacturers Association (NEMA)
standard 2 x 4 junction box. The sensor can be mounted direct-
ly on the wall surface if acceptable by local codes.
Do not mount the sensor in drafty locations (such as near
air-conditioning or heating ducts), over heat sources (such as
baseboard heaters or radiators), or directly above wall-mounted
lighting dimmers. Do not mount the sensor near a window
which may be opened, near a wall corner, or near a door.
Sensors mounted in these areas will have inaccurate and erratic
sensor readings.
The sensor should be mounted approximately 5 ft from the
floor, in an area representing the average temperature in the
space. Allow at least 4 ft between the sensor and any corner
and mount the sensor at least 2 ft from an open doorway.
Install the sensor as follows (see Fig. 17):
1. Locate the two Allen head screws at the bottom of the
sensor.
2. Turn the two screws clockwise to release the cover from
the sensor wall mounting plate.
3. Lift the cover from the bottom and then release it from
the top fasteners.
4. Feed the wires from the electrical box through the open-
ing in the center of the sensor mounting plate.
5. Using two no. 6-32 x 1 mounting screws (provided with
the sensor), secure the sensor to the electrical box.
6. Use a three-conductor 20 gage shielded cable. The wire is
suitable for distances of up to 500 ft. The standard CCN
(Carrier Comfort Network®) communication cable may
be used. If the set point adjustment (slide-bar) is not re-
quired, then an unshielded, 18 or 20 gage, two-conductor,
twisted pair cable may be used.
The CCN network service jack requires a separate,
shielded three-conductor CCN communication cable.
Always use separate cables for CCN communica-
tion and sensor wiring. (Refer to Fig. 18 for wire
designations.)
7. Replace the cover by inserting the cover at the top of the
mounting plate first, then swing the cover down over the
lower portion. Rotate the two Allen head screws counter-
clockwise until the cover is secured to the mounting plate
and locked in position.
For more sensor information see Table 12 for thermistor
resistance vs temperature values.
NOTE: Clean sensor with damp cloth only. Do not use
solvents.
Fig. 16 — Space Temperature Sensor
(P/N HH51BX005)
NOTE: Dimensions are in inches.
Fig. 17 — Space Temperature Sensor and
Wall-Mounted Humidity Sensor Mounting
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Cool Warm