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Click to View: Introduction Features Description Sampling the Tube Table Dimensions

INTRODUCTION
FARADAY air duct detector housings are designed to be used with 8710 & 8713 detectors. Designed for installation directly to heating, ventilating and air conditioning duct systems, they comply with National Fire Protection Association Standard No. 90A. When equipped with photoelectric detectors, these units will signal the presence of hazardous quantities of products of combustion or smoke being carried through the duct system. Air duct detectors are not intended to be substituted for open area detection.

8717 air duct housings can be equipped with optional relays. These relays are utilized to operate any supplementary equipment when smoke or particles of combustion are detected.

With the MPC-6000 or 7000 control panels, up to 252 detectors per circuit having relays may be used. The connection of a remote lamp or a remote relay is also allowed.

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FEATURES

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DESCRIPTION
The 8717 air duct housing is uniquely designed to use the photoelectric detector.

8710 sensitivity may be viewed from the multi-color LED on the detector or preferably may be printed by command on an optional printer from the control panel. The multi-color LED on the 8710 flashes green to indicate the detector has passed it’s self test and is within its proper sensitivity range. Yellow indicates either a ”Trouble” condition or an ”Out of Sensitivity” condition. Red indicates alarm.

The detector unit employs a cross-sectional sampling principle of operation. Inlet sampling tubes are available in four lengths (see table on reverse side). Outlet sampling tubes are one common length. A continuous cross-sectional sample of air moving through the duct is taken. This averages the effects of laminar flow, stratification or skin effect phenomena occurring in the duct that could prevent combustion product or smoke (especially in large ducts) from reaching a spot type detector.

In addition, the unique design of the sampling chamber insures uniform sensitivity in air velocities, ranging from a low of 300 feet per minute to as high as 4000 feet per minute. The inlet sampling tube length is determined by the width of the air duct being protected.

The inlet tube nearest to but greater than the duct width should be used (see table). The inlet tube can then be trimmed at the job site to the exact width of the duct. The outlet sampling tube for all ducts, irrespective of width, has a fixed length of approximately 3 inches (7.5 cm) and is supplied with the 8717 air duct housing.

Duct Width	Sampling TubeModel No.
9" to 1'9" (21 cm to 51 cm)	8932
1'9" to 3'3" (51 cm to 97.5 cm)	8933
3'3" to 6'3" (97.5 cm to 187.5 cm)	8934
6'3" to 9'9" (187.5 cm to 292.5 cm)	8935
Greater than 9'9" (292.5 cm)	Terminal Support Consult FARADAY

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SAMPLING TUBE SELECTION TABLE
Maintenance of the detector is easily accomplished by the removal of the duct housing sampling chamber cover. The detector, which plugs into the housing is easily removed for cleaning by a trained technician.

All that is necessary for the installation of the air duct detector is the cutting of three small holes for the sampling tube installation (template included) and the drilling of four holes for mounting the air duct housing. The unit is then easily mounted in place and connection made to the existing wires or terminals if optional accessories are utilized.

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Note to Architect
When building codes regulate the location of detectors within ventilating systems, make sure that the number and locations of detectors is in accordance with the code regulations.

Note
The 8717 air duct housing is used with 8710 & 8713 detectors on the MPC-6000 & 7000 control panel when a relay is required in the housing. If no relay is required, use the 8840 housing.

DIMENSIONS

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