Det-Tronics U5006 Air Duct Smoke Detector User Manual

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ENGINEERING SPECIFICATIONS

The air duct photoelectric smoke detector shall lock in on

alarm and have an alarm indicator LED visible through

the air sampling chamber cover. Detectors shall be

mounted exterior to the duct, with perforated sampling

tubes. Activation of a detector shall cause shutdown

of associated equipment through the control circuitry of

the fire alarm panel. The detector shall be mounted in a

readily accessible location.

The detector shall have SPST alarm contacts for the fire

alarm control panel and power supervision. In addition,

the detector shall be capable of activating a remote

indicating lamp on a remote annunciator.

The detector unit shall be designed for use in Class I,

Division 2, Groups A, B, C and D hazardous locations. A

junction box shall be furnished for connecting the system

wiring.

INSTALLATION

The U5006 Air Duct Smoke Detector mounts externally

on any duct wall with the air sampling and return air

tubes extending into the duct to provide a continuous

cross sectional sampling of the air moving through the

air handling system. Electrical equipment that is used in

conjunction with the smoke detector is connected to the

detector using a terminal strip located in the junction box

that is furnished with the unit.

NOTE

To prevent ignition of a hazardous atmosphere,
either de-classify the area or remove power from
the unit before opening the enclosure or junction
box.

Detector Location
Detectors can be mounted in the supply system

downstream of the filters or in the return system at the

point of entry into a common return duct. Whenever

possible, detectors that are mounted on a return duct

should be at a distance equivalent to six duct widths from

any duct openings, sharp bends, branch connections, or

deflection plates.

For additional information regarding the location and

spacing of duct smoke detectors, contact the National

Fire Protection Association, Batterymarch Park, Quincy,

MA 02269 and request a copy of NFPA Standard 90A,

Installation of Air Conditioning and Ventilation Systems

and NFPA Standard 72 for Automatic Fire Detectors.

MoUnting the Detector

Select the location for mounting the detector.

Mark and drill the appropriate mounting and sampling

tube holes on the duct wall. Refer to Figure 2 to

determine the size and location of the holes.

NOTE

To ensure proper operation of the sampling tube
within the air duct, be sure to observe proper
sampling and return tube position and orientation
as illustrated in Figure 3.

Attach the return tube to the detector housing by

sliding the tube into the connector body and rotating

the tube until the key notch slips over the alignment

pin in the connector. The opening at the end of the

tube is cut at an angle. This opening must always

face downstream or away from the direction of air

flow in the duct, as shown in Figure 3. Tighten the

compression nut until the tube is stable.
The sampling tube is available in 1, 3, 6, and 10 foot

lengths. As a rule, order the tube that is capable of

spanning the entire width of the air duct. For duct

widths of three feet or smaller, the sampling tube may

be cut to three quarters of the duct width. For duct

widths greater than three feet, the recommended

practice is to drill a hole on the duct wall directly

across from the sampling tube hole of the duct

detector. This provides the required support and

eliminates excessive stress on the compression nut

of the sampling tube connector. Be sure to seal any

gap around the hole to prevent air leakage.

NOTE

When cutting a sampling tube, always cut the end
opposite the notches. If the end with the notches
is cut, the tube will not seat in the connector
fitting properly and proper orientation may not be
possible. When the sampling tube is cut to the
proper length, install the rubber plug snugly in
the end of the tube.

To assure proper detector

operation, it is essential that the rubber plug be
installed at the end of the sampling tube.

Attach the sampling tube to the detector housing

using the compression nut on the connector in the

same way that the return tube was installed. Tighten

the compression nut until the tube is stable.

NOTE

The holes in the sampling tube must face the air
flow in the duct.