Det-Tronics C7052J UV/IR Flame Detector used with R7494, R7495 Controller - Manual (Page 7)

OPTIONS
Power supplies are available for operating the R7495B
and C7052J from line (mains) voltage.
Q4004 Mounting Cage is designed for holding up to
eight micro-module devices and is recommended for
ease of installation and servicing. Mounting cages that
hold fewer modules are also available. Optional filler
panels (part number 002188-001) can be used to cover
unused sections of the mounting cage.
Locking devices must be used on detector housings to
comply with applicable regulations in some areas
(BASEEFA/CENELEC).
Q1113 Air Shields for areas where there is an abnormal-
ly high level of airborne contaminants. Two Q1113 Air
Shields are required for each detector.
Q9001G Swivel Assembly (part number 004404-001) for
easy mounting and sighting of detector assemblies.
RESPONSE CHARACTERISTICS
The response time of the detector is a function of fuel,
fire size, distance, orientation of the fire source and the
field programmable controller settings. As with all fire
tests, results must be interpreted according to the indi-
vidual application, taking into account all possible vari-
ables (see the Application Guidelines” section for a dis-
cussion of of these factors).
Typical response distances of the C7052J Detector to
various fuels are listed in Table 1. Each liquid fuel fire
(acetone, diesel, gasoline, methanol, and toluene) con-
sisted of approximately one pint of fuel burned in a 1
foot by 1 foot steel pan unless otherwise noted. The
excelsior (wood shaving) fire consisted of one pound of
wood shavings. The wood fire consisted of a 10-inch by
10-inch crib (wood stack). The methane fire was per-
formed to FM standard, with the flame approximately 30
inches high and 6 to 8 inches in diameter. The detec-
tors were sited to observe the fire at center axis ±10
degrees. The controller sensitivity and time delay set-
tings were 4 counts per gate, 4 consecutive gates, and
0.25 second gate lengths.
APPLICATION GUIDELINES
Certain guidelines must be followed when using any
type of sensing device as a fire detector. This involves
not only recognizing the strengths and advantages of a
particular device, but also understanding its limitations.
It is also important to note that in any system that uses
two or more sensors to produce a fire signal, the detec-
tor will be disabled should one of its sensors fail. The
Automatic Oi feature will warn of such failure. Routine
manual testing and checking of the system is recom-
mended for increased system reliability.
Potential radiation sources in the environment must also
be carefully considered. A UV sensor will respond to
sources of UV besides fire, such as electric arc welding,
lightning, x-rays and gamma radiation. The C7052J has
been designed to ignore steady state infrared sources
that do not have a flicker frequency characteristic of a
fire, however, it should be noted that if these steady
state infrared sources are hot enough to emit adequate
amounts of infrared radiation in the response range of
the IR sensor and if this radiation becomes interrupted
from the view of the detector in a pattern characteristic
of a flickering flame, the IR sensor can respond. Any
object having a temperature greater than 0° Kelvin
(–273°C) emits infrared radiation. The hotter the object,
the greater the intensity of the emitted radiation. See
Figure 9. The closer the infrared source is to the detec-
tor, the greater the potential for the IR sensor to produce
7 95-8302
5-1/4 INCHES
(133 MM)
2-1/2 INCHES
(64 MM)
MOUNTING BASE
1/2 INCH NUT USED TO ADJUST
ELBOW TO DESIRED ANGLE
1-3/8 INCH NUT USED TO ROTATE
SWIVEL/DETECTOR ASSEMBLY
TO DESIRED POSITION
3/4 INCH NUT USED TO
SECURE DETECTOR
BRACKET TO SWIVEL MOUNT
JUNCTION BOX MOUNTING
BRACKET (ATTACHES
WITH TWO ENCLOSED
FLATHEAD SCREWS)
B1303
Figure 8—Q9001G Swivel Mounting Bracket Dimensions
Table 1—C7052J Typical Response Distances
Fuel Distance from U7652
Acetone 45 feet (13.7 meters)
Diesel 40 feet (12.2 meters)
Gasoline 50 feet (15 meters)
Methane 35 feet (10.7 meters)
Methanol 35 feet (10.7 meters)
Toluene 50 feet (15 meters)
Wood Shavings (Excelsior) 50 feet (15 meters)
Wood Stack (Crib) 50 feet (12.2 meters)
JP4 (surface area)
2 ft2 100 feet (30 meters)
4 ft2 150 feet (45 meters)
10 ft2 150 feet (45 meters)