Application Note DSDN
Issue Date May 21, 2003
© 2003 Johnson Controls, Inc.
1
Code No. LIT-1201602
www.johnsoncontrols.com
DSDN No Flow Duct Smoke Detector
Description
The DSDN No Flow Duct Smoke Detector is designed
for use with Johnson Controls® UL555S classified
smoke dampers. The device detects the presence of
smoke in the airstream of ductwork in Heating,
Ventilating, and Air Conditioning (HVAC) systems
without a minimum operating velocity.
Model:
System Sensor® 2151
Type:
Photoelectronic
Velocity:
0 to 3,000 fpm.
Dimensions (Dia.):
6.1 in.(155 mm)
Weight:
3.6 oz. (104 g).
Operating Temperature Range:
32° F to 120° F
(0° C to 49° C).
Operating Humidity Range:
10% to 93% Relative
Humidity.
Operating Voltages:
120 VAC operation.
Contact Ratings:
Form A: 2.0A @ 30 VAC/VDC,
Form C: 0.6A @ 110 VDC, 2.0A @ 30 VDC,
1.0A @ 125 VAC, 2.0A @ 20 VAC
Underwriter's Laboratories®, Inc. (UL) does not have a
separate Product Category for factory mounted smoke
detectors. The smoke detector and the damper have
been individually evaluated by their applicable UL
standards. The local authority having jurisdiction
should be consulted prior to installation of the damper
and smoke detector.
•
UL Listed:
file S911
•
standard cubic feet/minute (scfm) Listing:
7272-1209:159
•
New York:
MEA-205-94-E
•
Factory Mutual Approved:
OX5A4.AY
Application
National and local safety standards and codes
recognize the ability of air duct systems to transfer
smoke, toxic gases, and flame from area to area.
Smoke can be a serious hazard to life safety unless
blowers are shut down and dampers are actuated.
The primary purpose of duct smoke detection is to
prevent injury, panic, and property damage by
reducing the spread of smoke. Duct smoke detection
can also serve to protect the air conditioning system
itself from fire and smoke damage, and can be used to
assist in equipment protection applications. When the
presence of smoke in the duct is sensed, or when loss
of power occurs, the damper will fail close.
Consult NFPA90A, NFPA72 documents and local
codes to determine where smoke detectors are
required. DSDN No Flow Duct Smoke Detectors are
factory mounted for single point field wiring
connection.
Maintenance and Service of Duct
Detectors
Dust, dirt, and other foreign matter can accumulate
inside a detector and change its sensitivity. Detectors
should be tested and maintained periodically. Routine
maintenance should be performed at least once a year
and more frequently in dirtier environments. Refer to
NFPA90A, NFPA72, and detector manufacturer's
instructions packaged with each detector for specific
maintenance and testing information.
