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A6V10323934_c_en_--

SIEMENS Industry, Inc.

2020-01-16

Smart Infrastructure

Installation Instructions
Model FDOT421

Multi-Criteria Smoke Detector

UL268 7th edition listed

Figure 1

These  instructions  are  written  in  accordance  with  the
installation guidelines of NFPA 72, National Fire Alarm
Code, and CAN/ULC-S524, The Installation of Fire Alarm
Systems.

Do  not  locate  the  detectors  next  to  an  oil  burner,  or
garage where exhaust fumes can trigger an alarm. Other
causes  of  false  alarms  are  dust  accumulation,  heavy
concentrations of steam, heavy pipe or cigar smoke, and
certain aerosol sprays.

CAUTION

DO NOT install this detection device until all construction
is completed.
DO  NOT  store  this  detection  device  where  it  can  be
contaminated by dirt, dust, or humidity.

AIR CURRENTS

Before  a  detector  can sense  a  fire,  the  products  of
combustion  or  smoke  must  travel  from  the  fire  to  the
detector.  This  travel  is  especially  influenced  by  air
currents;  therefore,  consider  air movement  when
designing the system. While combustion products tend
to rise, drafts from hallways, air diffusers, fans, etc., may
help or hinder the travel of combustion products to the
detector.  When  positioning  a  detector  at  a  particular
location, give consideration to windows and doors, both
open and closed, to ventilating systems, both in and out
of  operation,  and  to  other  factors  influencing  air
movement. Do not install a detector in the air stream of
a  room  air  supply  diffuser.  It  is  better  to  position  a
detector closer to an air return.
The  distance  that  products  of  combustion  or  smoke
travel from a fire to the detector is not usually the shortest
linear route. Combustion products or smoke usually rise
to the ceiling, then spread out. Average ceiling heights of
8 to 10 feet do not abnormally affect detector response.
High  ceilings,  located  in  churches,  warehouses,
auditoriums, etc., do affect detector response and should
be considered.

SPECIAL CEILING CONSTRUCTION FACTORS

Ceiling obstructions change the natural movement of air
and combustion products. Depending on the direction of
smoke travel, joists and beams can slow the movement
of  heated  air  and  smoke,  while  pockets  between them
can contain a reduced level of smoke. Take obstructions
created by girders, joists, beams, air conditioning ducts,
or  architectural  design  into  consideration  when
determining  area  protection.  Refer  to  the  Initiating
Devices chapter of NFPA Standard 72 for Location and
Spacing requirements for specific types of construction;
e.g.  beam,  suspended,  level,  sloped  and  peaked
ceilings.  The  detector  is  also  compatible  with  the
following mechanical protection guard model: STI-9604
(see www.STI-USA.com for details).

DETECTOR PLACEMENT

Although no specific spacings are set for the detectors
used  for  a  clean  air  application,  use  30-foot center
spacing  (900  sq  ft)  from  NFPA  Standard  72  initiating
devices  chapter  and  CAN/ULC-S524,  if  practical,  as  a
guide or starting point for a detector installation layout.
This  spacing,  however,  is  based  on  ideal  conditions –
smooth  ceiling,  no  air  movement,  and  no  physical
obstructions. 

In 

some 

applications, 

therefore,

considerably less area is protected adequately by each
smoke  detector.  This  is  why  it  is  mandatory  to  closely
follow the installation drawings. In all installations place
the detector on the ceiling, a minimum of 6 inches from
a side wall, or on a wall, 12 inches from the ceiling.
If the detector is used as heat only

locate it on the

ceiling, at least 4 inches from the side walls. For an
ideal, smooth ceiling condition, place the detectors at a
maximum center spacing of 50 feet (2500 square

feet).

  Drawings  provided  or  approved  by  Siemens

Industry,  Inc.,  or  by  its  authorized  distributors  are
extremely important

.

The detector placements shown on

these drawings were chosen after a careful evaluation of
the area that is protected. Such factors as air currents,
temperature,  humidity,  pressure,  and  the  nature  of  the
fire  load  were  carefully  considered.  Especially  noted
were  the  room  or  area  configuration  and  the  type  of
ceiling  (sloped  or  flat,  smooth  or  beamed).  Siemens
Industry, Inc.’s extensive experience in the design of the
system assures the best detector placement by following
these  drawings. Sound  engineering  judgment  by
qualified personnel must be followed.

TO AVOID NUISANCE ALARMS

Do  not  locate  the  detectors  where  excessive  smoke
concentrations exist under normal conditions, or in areas
of prolonged high relative humidity where condensation
occurs.

Содержание FDOT421

Страница 1: ...smoke while pockets between them can contain a reduced level of smoke Take obstructions created by girders joists beams air conditioning ducts or architectural design into consideration when determining area protection Refer to the Initiating Devices chapter of NFPA Standard 72 for Location and Spacing requirements for specific types of construction e g beam suspended level sloped and peaked ceili...

Страница 2: ...he parameter setting Robust is changed to Duct which shall only be used in Duct applications When using this detector direct in air duct applications be sure the detector is set to the parameter Duct Alarm source 2 Heat only Fixed 135 F 57 C Rate of rise detection 15 F min 8 3 C at fixed 135 F 57 C WIRING The FDOT421 supports two operation modes polarity insensitive mode and isolator mode The Dete...

Страница 3: ...r is marked DO NOT PAINT This is intended to prohibit painting during routine maintenance of the occupancy which can affect proper operation of the detector Polarity insensitive wiring Figure 2 Isolator mode wiring Figure 3 Wire size maximum 14 AWG minimum 18 AWG Wire larger than 14 AWG can damage the connector TO INITIATING CIRCUIT OF SIEMENS COMPATIBLE CONTROL UNIT OPTIONAL REMOTE ALARM INDICATO...

Страница 4: ...the same loop with the modules in isolator mode FCC Statement WARNING Installation and usage of equipment not in accordance with instructions manual may result in Radiation of radio frequency energy Interference to radio communications Install and use equipment in accordance with installation instructions manual Read the following information This equipment generates uses and can radiate radio fre...

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