Carrier 50HCQA Flexible Exhaust Tube, Sampling Tube, Return Air with Economizer

location and the tubing to the sampling tube be connected.

See “Completing Installation of Return Air Smoke

Sensor:” for details.)

Return Air Detector module (shipping position shown)*

Controller module

Return Air Detector Sampling Tube

*RA detector must be moved from shipping position to operating position by installer

C07307

Fig. 61 - 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. 62. The holes in the sampling tube face downward, into the return air stream. The sampling tube is connected via tubing to the return air sensor that is mounted on a bracket high on the partition between return filter and controller location. (This 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 the following installation procedure.)

Flexible

Exhaust Tube

Completing Installation of Return Air Smoke Sensor:

1.Unscrew the two screws holding the Return Air Sensor detector plate. See Fig. 63. Save the screws.

Controller

Screws

Flexible

Exhaust

Tubes

Sampling Tube

C10331

Fig. 63 - Return Air Detector Shipping Position

2.Remove the Return Air Sensor and its detector plate.

3.Rotate the detector plate so the sensor is facing out- wards and the sampling tube connection is on the bot- tom. See Fig. 64.

50HCQA

	Sampling Tube
	C10332
	Fig. 64 - Return Air Sensor Operating Position
	4. Screw the sensor and detector plate into its operating
	position using screws from Step 1. Make sure the
	sampling tube connection is on the bottom and the ex-
	haust tube is on the top. See Fig. 64.
	5. Connect the flexible tube on the sampling inlet to the
Return Air	sampling tube on the basepan.
Sampling Tube	Additional Application Data —
	Refer to Catalog No. HKRNKA-1XA for discussions on
	additional control features of these smoke detectors
C10330	including multiple unit coordination.
Fig. 62 - Return Air Sampling Tube Location

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