The Pyrotector Model 30-3003 Explosion Proof Smoke Detec-
tor is a sensitive yet rugged protection device that is designed
for use in hazardous industrial and commercial locations. The
detector is designed to operate effectively with both slow smol-
dering and fast burning fires.
- Rugged construction.
- Self checking and compensating circuitry maintains desired
- Heightened sensitivity triggered when smoke is increasing,
but has not yet reached the preset sensitivity setting.
- Form A (SPST) N.O. contacts for connection to alarm output circuitry.
- SPST N.C. contacts for supervision of input power.
- 2.3% fixed sensitivity.
Construction & Operation
- Combustible storage facilities.
- Munitions manufacturing.
- Volatile chemical storage.
- Chemical processing plants.
- Petroleum refineries.
- Turbine enclosures.
The photoelectric smoke detector uses a solid-state infrared-emitting diode (IRED) and a light-sensing photovoltaic cell
arranged in a labyrinth assembly. The labyrinth permits free
access to smoke but restricts external light. Because of its
critical function to the operation of the detector, each IRED is
selected with extreme care and is subjected to rigorous preproduction testing to ensure long-term reliability and performance.
During normal operation (no smoke), the detector samples the
air approximately every four seconds for a period of less than
one millisecond. The photovoltaic smoke cell, which is placed
at an angle to the pulsed invisible light source, is sensitive to
the infrared light in the specified frequency emitted by the
IRED light source and is designed to receive a signal only
when the pulsed IRED source is activated. See “Cross Section of Sensing Chamber Assembly” at top of opposite column.
When smoke enters the chamber, the light from the IRED
reflects off the smoke particles and reaches the photovoltaic
smoke cell. When the amount of light reflected by smoke
reaches the factory-set threshold level, the smoke alarm circuit
The detector will respond to a slow smoldering fire when
smoke in the chamber reaches the preset sensitivity setting,
If a fast-burning fire should occur, including fires in flammable
liquids and other materials such as plastics that generate black
smoke, the abnormally rapid movement of smoke into the
detection chamber is sensed by a special rate-compensating circuit. An increase in smoke within the detection chamber
that exceeds a preset rate causes the rate-compensation circuit to increase the intensity of the light source, which
increases detector sensitivity. If the smoke continues to build
at this rate, an amplifier circuit is triggered and the unit generates an alarm. If not, the detector reverts to normal sensitivity.
In normally smoky atmospheres, the detector will not go into
alarm as long as the concentration is less than the fixed sensitivity of the detector. This results in a sensitive and positive
response with a very low potential for unwanted alarms.
The main enclosure of the detector contains the electronic circuitry, alarm relay, and supervision relay.
Fail-safe Operation. To ensure reliable operation, the Model
30-3003 is equipped with self-checking circuitry. A regulation
photodiode, which is matched to the smoke detection circuit,
continuously monitors the output intensity of the IRED and
adjusts it as necessary to compensate for an accumulation of
dust or other contaminants, or any other variation that can
occur with temperature and time. A power supervision relay in
the detector provides a trouble output signal in the event of an
input power failure.
The detector uses extensive filtering against RF and transient
interference. In addition, there is a two-second time delay
before an alarm is generated.
The printed circuit board inside the detector is coated to minimize the possibility of problems caused by moisture accumulation.
Detector Outputs. The detector provides a set of Form A
(SPST) N.O. contacts for connection to the alarm output circuitry and a set of SPST N.C. contacts for supervision of input
power. An auxilliary set of Form C (SPDT) NO/NC alarm relay
contacts is also provided for controlling remote annunication devices. The alarm output latches on in the event of an alarm
and an LED located on the outer surface of the housing is illu-
minated to provide a visual indication that an alarm condition
has occurred. The detector is reset by momentarily interrupt-
ing input power.
Classification. The Model 30-3003 is designed to meet NEC
requirements for Class I, Division 2, Groups A,B, C and D;
hazardous areas. CSA certified for use in Class 1, Division 2,
Groups A,B, C and D hazardous locations.
Explosion-Proof Certification. The Model 30-3003 is certi-
fied by the German Electric Industry Association, VDE, to
meet Standards 0171/ “Special Protection” (Ex)sG5 (sand
encapsulated), and PTB/CENELEC approved as EEx q II T5.
The Model 30-3003 is intended for surface mounting. The
mounting screw holes are counterbored for No. 8 flat-head
screws. 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
NOTE: For maintenance information see your product documenta-
The smoke detector is normally mounted on the ceiling not
less than six inches from a side wall. The exact location of the
detector must be determined by an evaluation based on engi-
neering judgment supplemented, if possible, by field tests.
For additional information on detector location and spacing,
contact the National Fire Protection Association, Battery-
march Park, Quincy, Massachusetts 02269, and request a
copy of NFPA Number 72, the Standard on Automatic Fire
The Model 30-3003 contains two sets of relay contacts.
- One set of N.O. Alarm contacts close upon detection of
- One set of N.C. Trouble contacts close when the detector
The detector shall be a 2.3% fixed sensitivity photoelectric
smoke detector, providing minimum response time to all fire
The detection chamber shall extend beyond the main housing
into the area to be protected, to provide maximum smoke entry
capability into the chamber from any direction.
The detector light source shall be an IRED (Infrared Emitting
Diode). Typical detector current consumption in the standby
condition shall be 10 milliamperes.
The detector shall lock in on alarm and have a visible alarm
The detector shall have SPST alarm relay contacts for connec-
tion to the fire alarm control panel and also power supervision
The detector enclosure shall be an explosion-proof flanged
housing designed to meet CSA certification for use in Class 1,
Division 2, Groups A, B, C and D hazardous locations.
The detector shall be intended for surface mounting and con-
nection to the system wiring shall be within a rated enclosure