Det-Tronics 95-8311-02 User manual

Instructions 95-8311-02
UV/IR Flame Detection System
R7494 Controller/C7052J Detector
Detector Electronics Corporation
6901 West 110th Street •Minneapolis, Minnesota 55438 USA
Tel: [phone] or 800.765.3473 •Fax: [phone]-8311-02

APPLICATION........................................................................1
FEATURES.............................................................................1
SYSTEM DESCRIPTION .......................................................2
Detector...........................................................................2
oiFeature .......................................................................2
Detector Enclosure..........................................................3
Controller.........................................................................3
Front Panel......................................................................3
Programming Switches....................................................4
Controller Outputs ...........................................................5
Field Wiring Connector....................................................7
SPECIFICATIONS..................................................................7
OPTIONS................................................................................9
RESPONSE CHARACTERISTICS.........................................9
APPLICATION GUIDELINES .................................................9
INSTALLATION ....................................................................11
Detector Positioning ......................................................11
Wiring Requirements.....................................................11
Detector Mounting and Wiring Procedure .....................12
Controller Installation and Wiring...................................17
Electrical Connections...................................................17
Programming the Controller ..........................................19
TYPICAL SYSTEM APPLICATION ......................................23
STARTUP PROCEDURE.....................................................24
INITIAL AND PERIODIC CHECKOUT PROCEDURE..........24
Bus Test Mode ..............................................................26
Star Programming Checkout Procedure........................26
MAINTENANCE....................................................................27
Sensor Module Replacement Procedure.......................27
TROUBLESHOOTING..........................................................28
Manual oiTest..............................................................28
Count Test Mode...........................................................28
DEVICE REPAIR AND RETURN .........................................29
ENGINEERING SPECIFICATIONS......................................30
ORDERING INFORMATION ................................................31
Accessories ...................................................................31
Recommended Spare Parts ..........................................31
APPLICATION ASSISTANCE ..............................................31
List of Illustrations
Figure 1 Detector Sensitivity Range ..................................2
Figure 2 oiFunction within the Detector...........................3
Figure 3 Front Panel of R7494 ..........................................3
Figure 4 Open Controller Outputs with Transient
Suppression Device Connected ..........................6
Figure 5 Intercontroller Communications...........................6
Figure 6 Cone of Vision .....................................................7
Figure 7 Detector Dimensions in Inches (mm) ..................8
Figure 8 Dimensions of R7494 in Inches (mm) .................8
Figure 9 Blackbody Spectral Emittance...........................10
Figure 10 Front View of the C7052 Detector .....................12
Figure 11 C7052J Detector Part Identification...................13
Figure 12 Mounting Base Dimensions...............................13
Figure 13 Q9001G Swivel Mounting Bracket Dimensions.13
Figure 14 Detector Terminal Block ....................................15
Figure 15 Detector and Power Connections......................15
Figure 16 Cover Locking Assembly (Optional) ..................16
Figure 17 Jumper Plug ......................................................16
Figure 18 IR Module with Four-Wire Connector ................16
Figure 19 Q4004 Mounting Cage Dimensions in
Inches (mm).......................................................17
Figure 20 Terminal Configuration ......................................18
Figure 21 Rocker Switch Setting .......................................19
Figure 22 Graphic Representation of STAR Logic
(Typical Settings Shown)...................................20
Figure 23 Multiplication Factors.........................................22
Figure 24 System Layout Chart.........................................23
Figure 25 Block Diagram of a Typical R7494 System
Application.........................................................24
Figure 26 Data Bus Wiring.................................................25
List of Tables
Table 1 Relationship of Zone and Status Codes..............5
Table 2 C7052 Typical Response Distance .....................9
Table 3 Radiation Absorbing Gases and Vapors ...........10
Table 4 Relationship of ZONE and DETECTOR
Display to the Status Outputs............................18
Table 5 Relationship of SYSTEM STATUS Display to
Status Outputs...................................................19
Table of Contents

APPLICATION
The R7494/C7052J UV/IR Flame Detection System is
designed to provide continuous and automated fire
protection in applications where the use of ultraviolet
(UV) or infrared (IR) detectors alone can result in
unwanted (false) alarms. The R7494/C7052J system
features a flame detector that uses both a UV and a
single frequency IR sensing device mounted side-by-
side on a junction box assembly.
When used alone, a UV detector can respond to
sources of ultraviolet radiation besides fire, such as
lightning, x-rays or arc welding. A UV detector does
not respond to the radiation emitted by flickering hot
objects. Likewise, an IR detector can respond to
infrared radiation sources besides hydrocarbon fires,
such as flickering hot objects. An IR detector does
not respond to radiation from lightning, x-rays or arc
welding. Since both UV and IR sensors respond to
hydrocarbon fires but have virtually no false alarm
sources in common, the R7494/C7052J UV/IR system
provides reliable flame detection while being virtually
immune to false alarms.
The junction box contains a power supply and signal
processing circuitry for the sensors. A fire signal is
generated in the detector junction box and sent to the
controller only when a fire is simultaneously detected
by both the UV and IR sensors. Since the two detect-
ing elements independently monitor different portions
of the radiation spectrum and have virtually no
sources of output actuation in common besides fire, a
high degree of false alarm immunity is achieved. The
controller continuously monitors up to eight UV/IR
detectors and generates a fire alarm in response to a
fire signal from the detectors.
Typical applications include:
—Transport loading terminals
—Offshore drilling and production platforms
—Tank farms
—Refineries
—Butane and propane loading and storage
—Pipeline compressor stations
—Turbine enclosures
—Aircraft Hangars
—Paint Spray Booths
—Chemical and petrochemical production
FEATURES
• Controller continuously monitors up to eight detec-
tors.
• Ignores false alarm sources such as arc welding, x-
rays, gamma radiation and radiation from flickering
hot objects.
• Fast response - typically 1 to 5 seconds for an
intense hydrocarbon fire.
• Each detector can independently register an alarm.
INSTRUCTIONS
UV/IR Flame Detection System
R7494 Controller
C7052J Detector
©Detector Electronics Corporation 1994 5/94 95-8311-02
DET-TRONICS®
*oiis Detector Electronics' Trademark for its patented Optical
Integrity Systems, U.S. Patent 3,952,196, United Kingdom Patent
1,534,969, Canada Patent 1,059,598.

• Front panel LEDs indicate fire response and general
system status.
• Microprocessor control provides continuous diag-
nostics and automatic fault identification.
• Automatic Optical Integrity (oi) for both UV and IR
sensors.
• Explosion-proof (flame-proof) detector housing
• FM approved, CSA and BASEEFA/CENELEC certi-
fied.
• Count test mode allows monitoring of actual detec-
tor output.
• Bus test mode allows verification of data bus wiring.
• Voting circuitry for improved false alarm rejection.
• Up to eight controllers can be wired to provide up to
64 voting detector zones.
SYSTEM DESCRIPTION
DETECTOR
The C7052J UV/IR Flame Detector is an explosion-
proof device that consists of a UV sensor and an IR
sensor mounted side-by-side on a junction box. This
mounting arrangement allows both sensors to monitor
the same hazardous location with a 80 degree cone
of vision. Up to eight C7052J Detectors can be con-
nected to one R7494 Controller.
The UV sensor responds to high energy radiation with
wavelengths from 0.185 to 0.245 microns (1850 to
2450 angstroms). See Figure 1. It detects radiation
from sources such as fire, arc welding, lightning, x-
rays and gamma rays. However, it is not sensitive to
radiation from the sun or radiation from flickering hot
objects (blackbodies).
The IR sensor is sensitive to IR radiation over the
range of 4.2 to 4.7 microns. See Figure 1. It is not
sensitive to radiation from the sun, lightning, x-rays,
gamma rays, or arc welding. However, it will respond
to fire and flickering blackbody (heat) radiation
sources. IR radiation that is generated by a hydrocar-
bon flame which reaches the detector in pulsations or
“flicker.” These pulsations are present in all flames
and are created by turbulent mixing of fuel with air.
For this reason, electronic circuitry in the detector
monitors the output of the IR sensing element for the
appropriate amplitude and a flicker frequency
between 1 and 16 cycles per second. If both the
radiation and flicker requirements are met, a fire sig-
nal is generated. This dual criteria for the IR detector
results in increased reliability. However, since the IR
detector responds only to hydrocarbon fires, the
UV/IR detector cannot respond to non-hydrocarbon
fires such as burning hydrogen, ammonia or metal.
The detector junction box contains a +290 vdc power
supply for the UV sensor as well as circuitry to pro-
cess signals from both sensors. When both sensors
detect a fire, the IR sensor activates the circuitry in
the junction box to allow the signal from the UV sen-
sor to be sent to the controller. By using both a UV
and an IR sensor, the C7052J is able to discriminate
virtually all false alarm sources from a true hydrocar-
bon fire.
oiFEATURE
Both sensors are equipped with the automatic oitest
feature. This patented system assures proper opera-
tion of the detector by checking the cleanliness of the
optical surfaces, sensitivity of the sensors and proper
functioning of the electronic components of the detec-
tor once every minute. If a problem should occur, it is
quickly detected. The oi test is accomplished with-
out the use of an external UV or IR source. To mini-
mize the possibility of nuisance fault signals, the
detector must fail the automatic oitest three consec-
utive times for an oifault signal to be generated
The oitest is initiated by a signal from the controller
which causes actuation of the oitest lamps. A cali-
brated low level test beam is generated by the oitest
lamps, as shown in Figure 2. Although the test lamps
are mounted in the same enclosure with the sensor,
an optical shield prevents the test beam from reach-
ing the sensor directly. The test beam travels out
through the viewing window, where it encounters the
2
Figure 1—Detector Sensitivity Range
5.04.03.02.01.51.00.90.80.70.60.50.40.30.20.1
ATMOSPHERIC
TRANSMISSION
WAVELENGTH (MICRONS)
SOLAR RADIATION REACHING THE EARTH
VISIBLE INFRARED
ULTRAVIOLET SENSOR RESPONSE
ULTRAVIOLET
100
75
50
25
0
A1516
INFRARED SENSOR RESPONSE

reflective oiring and is directed back through the
window to the sensor. Electronic circuitry in the
detector then evaluates the return signal from the sen-
sor and generates the appropriate output response.
Since the test beam must pass through the same por-
tion of the viewing window as radiation produced by a
fire, this test of the ability of the detector to “see” a
flame has a high degree of reliability.
DETECTOR ENCLOSURE
The C7052J features an explosion-proof, dust-tight
and water-tight (NEMA 4/IP66) housing that is
designed for installation in hazardous locations in
both indoor and outdoor environments. The enclo-
sure is FM approved, CSA certified and BASEEFA/
CENELEC approved.
CONTROLLER
The R7494 is designed for use with 24 volt dc power
supplies, but will operate from any direct current sup-
ply between 18 and 32 volts. The unit will tolerate
transients such as those that can occur when fully
discharged batteries are placed on charge. When
power is present at the R7494 Controller, it is indicat-
ed by a continuously energized green LED. All other
lights and displays on the R7494 front panel are nor-
mally off, but may be periodically checked for opera-
tion by pressing the LAMP TEST button located
directly opposite the POWER light as illustrated in
Figure 3. It is not necessary for the controller to be in
the TEST mode when this check is performed.
With power applied, the R7494 Controller continuous-
ly cycles through the Automatic oitest (see the “oi
Feature” section), checking each detector and its
wiring. At the same time, it monitors the system for
any status changes, such as a fault, a “fire” signal
from one of the detector zones, or a change in the
setting of the keylock switch. If a status change
occurs, the controller will respond accordingly by
indicating the change on the front panel and generat-
ing the appropriate output.
FRONT PANEL
The front panel of the R7494 provides switches for
selecting mode of operation and initiating test func-
tions. It also provides LEDs and digital displays for
indicating system status information. Figure 3 illus-
trates the front panel of the controller.
3 95-8311
UV DETECTOR
IR DETECTOR
UV TEST LAMP
OPTICAL SHIELD
VIEWING WINDOWSNAP-IN oiRING
IR TEST LAMP (2)
IR SENSING ELEMENT
SNAP-IN oiRING
OPTICAL FILTER
VIEWING WINDOW
UV SENSOR
B1048
Figure 2—oiFunction within the Detector
A1711
KEYLOCK SWITCH
AMBER LED
TEST/ACCEPT
RED LEDS
LAMP TEST
DETECTOR SELECTION
AMBER LED
GREEN LED
Figure 3—Front Panel of R7494

1. A ZONE OUTPUT LED is provided for each
detector to indicate that a fire has been detected.
The LEDs blink while the zone output is active and
latch on when the fire is no longer detected and the
output turns off.
2. The FIRE LOGIC LEDs signal actuation of the cor-
responding Logic outputs.
3. The DETECTOR - ZONE digital display indicates
the detector zone number that first responded to
a fire, detector(s) indicating a fault, detector zone
selected manually in the keylock switch Test
mode, or the counts per second reading from the
detector zone in the Count Test mode.
4. The SYSTEM STATUS display uses a numerical
code to identify system status (see Table 1).
5. Illumination of the FAULT LED indicates a system
malfunction (or that the controller is in the Reset
or Test mode).
6. The INHIBIT LED is energized in the Test or Reset
mode to show that the outputs of the controller
are inhibited.
7. The POWER LED is illuminated when power is
applied to the system.
8. The SELECT button is pressed to choose a detec-
tor for test.
9. In the Test mode the TEST/ACCEPT button initi-
ates a manual oitest for the selected detector.
In the Normal mode, the TEST/ACCEPT button is
used to disable the alarm output when a fire
occurs without affecting the Zone or Fire Logic
outputs.
10. The LAMP TEST button illuminates all LEDs and
all segments of the displays. In the Reset mode,
it initiates a complete microprocessor reset.
11. The keylock switch selects NORMAL, RESET or
TEST mode.
Normal Mode
In the Normal operating mode, the R7494 Controller
monitors the outputs of all detectors connected to it
and compares the detector output signals to field
adjusted settings (refer to the “STAR Logic
Programming” procedure in the “Programming the
Controller” section) to determine whether a fire condi-
tion exists. Diagnostic circuitry continuously checks
the system for wiring continuity as well as faults that
could prevent proper response to a fire through the
Automatic oifeature. The Zone, Fire Logic and Fire
Alarm outputs are de-energized. The Fault output is
energized, as long as no system malfunctions are
detected. None of the LEDs except the POWER LED
are illuminated and the digital displays are blank.
Reset Mode
Any existing system status indications and the con-
troller outputs are returned to normal operating condi-
tion (after the radiation source is removed or the fault
is corrected) in one of the following ways:
1. Place the keylock switch in the RESET position,
then return it to NORMAL.
2. Close the optional remote reset switch connected
to controller terminal 44 and circuit ground (termi-
nal 2).
Test Mode
In the Normal mode, the Automatic oifeature continu-
ously checks the detectors for proper operation.
Additional manual oitesting capabilities are provided
by using the controller Test mode. Among the possi-
ble tests are:
1. A Manual oitest, which individually tests the
selected detector and its electronic circuitry.
2. A Count Test mode, which displays the output fre-
quency of an individual detector using the
DETECTOR and ZONE displays.
3. A Bus Test mode, which tests the data bus wiring
and indicates results on the front panel of the
controller when intercontroller voting is used.
These test features enable the user to more easily
pinpoint a system malfunction. Refer to the
“Troubleshooting” section.
PROGRAMMING SWITCHES
Rocker switches that are located on the side of the
controller are used for selecting various options avail-
able with the R7494. These programming options are
listed below and must be set prior to system opera-
tion. Refer to the “Programming the Controller” sec-
tion for detailed instructions.
1. Number of detectors connected to the controller
(up to eight)
2. Gate Length, Consecutive Gate Selection, Count
Selection (system sensitivity and time delay).
3. Fire Logic (voting arrangement)
4. Latching/non-latching outputs.
5. Intercontroller voting.
4

CONTROLLER OUTPUTS
The R7494 has Open Collector Transistor Outputs
rated at 100 ma maximum (not to exceed 60 vdc) for
external indication of system status. These outputs
along with a brief description are listed below. An
internal 100 kilohm resistor is connected from the out-
put to circuit ground (terminal 2).
NOTE
External equipment that may generate transients
when switching (such as relays) should have a
transient suppression device connected across
the coil at the time of installation to safeguard the
output transistors against possible damage (see
Figure 4).
Zone Outputs - Each of the eight detectors has
its own independent Zone output that is ener-
gized upon detection of a fire that exceeds the
selected duration (gate length and consecutive
gates) and the selected intensity (count selec-
tion). An LED on the front panel illuminates to
show the zone output is active.
5 95-8311
System
Zone Status Condition
0 0 Keylock switch is in reset position, or the external inhibit being used.
(Outputs inhibited, except Status Outputs.)
1 to 8 1 Keylock switch is in TEST position. (Outputs inhibited, except Status
Outputs.)
1 to 8 2 oi
fault - either the
oi
ring and/or the window of the zone indicated
in the upper right display is dirty, or the detector module has lost
sensitivity, or there is a wiring fault between the detector and the
controller of power supply, or the detector module is missing, or the
electronics module in the detector junction box is defective, or power
to detector is below the 18 vdc minimum.
Blank 3 One or more detectors are responding to a UV/IR source that has
not yet met consecutive gate time or is not large enough to reach the
fire threshold programmed into the controller. FAULT LED is not
turned on. Affected ZONE OUTPUT LED blinks slowly (1 per sec-
ond). This status does not latch on. The normally energized Fault
output remains energized.
Blank 4 Low +5 vdc caused by failure in the regulating network in the con-
troller.
Blank 5 High +5 vdc caused by failure in the regulating network in the con-
troller.
6 Fire Output Signal - Blinking ZONE OUPUT LED indicates fire loca-
tion. Steady ZONE OUTPUT LED indicates that the detectors in
that zone have responded to a UV/IR signal, but are no longer
responding. Zone Display the first zone that registered the alarm
condition.
Blank 7 Data Bus fault
1 to 8 8 Controller has been placed in "count" mode (see "Checkout" sec-
tion). Pushing and releasing both SELECT and TEST/ACCEPt but-
tons at the same time while the keylock switches in the TEST posi-
tion changes the lower display to a numeral "8" - the count rate of
each zone.
Blank Blank FAULT LED is on, indicating a problem in the R7494 microprocessor
circuitry. Place keylock switch in RESET, push and release LAMP
TEST pushbutton. If operation does not return to normal, replace
the entire R7494 BE SURE the new R7494 is programmed the same
as the R7494 being replaced.
Table 1—Relationship of Zone and Status Codes

Fire Logic Output(s) - If the fire signals from the
responding detectors satisfy the selected voting
requirements, actuation of the Fire Logic output(s) will
also occur. This voting logic feature allows detectors
to be “grouped” and generate a Fire Logic output if
the minimum number of detectors respond to a fire.
The detectors can be grouped in one of two ways:
1. Separate Voting
The eight fire zones (detectors) are divided into two
groups: Fire Logic A (zones 1 to 4) and Fire Logic B
(zones 5 to 8). The controller can then be pro-
grammed to produce a logic output when either one
or two of the four zones in a group detects a fire.
2. Common Voting
All eight fire zones (detectors) vote together in one
group. When the minimum number of detectors sig-
naling a fire condition meets the field selectable vot-
ing requirements (1 to 7 detectors) the Fire Logic B
output is energized.
The common voting feature can also be used in multi-
ple controller systems. Up to eight controllers can be
connected by way of the data bus to allow inter-con-
troller voting of up to 64 detectors in a group. The
controllers are connected in series so alarm informa-
tion from the first controller (master) is sent to the sec-
ond (slave) and then down the line to the following
slave controllers (see Figure 5). Note that the infor-
mation transfer moves in one direction only. Alarm
information from the end controller does not return to
the master controller. Each controller in the series
can be programmed to energize its Logic B output
when the minimum number of detectors (one to
seven) connected to it and/or “upstream” controllers
detect a fire. Fault output (terminal 46) and Alarm
output (terminal 43) information is not transferred over
the data bus and must be monitored separately when
inter-controller voting is utilized.
A data bus test is automatically executed by the con-
troller fault detection circuitry to verify correct connec-
tions of the data bus lines and proper functioning of
the inter-controller communication circuitry.
This voting logic feature allows different combinations
of detectors to fulfill the logic requirements, and pro-
vides the best balance between dependable fire
detection and freedom from false alarms.
Alarm Output - If a UV/IR detector sends a signal that
exceeds the gate length, consecutive gates and
count selection requirements, a solid state alarm out-
put is immediately energized. This alarm output is
typically used to control an external device for visually
or audibly signaling a fire condition.
Ext Reset/Inhibit - Connecting a switch between termi-
nal 44 and circuit ground (terminal 2) allows the con-
troller to be reset or inhibited from a remote location.
Outputs Inhibited - Connecting an indicating device
to the solid state output (terminal 45) provides a sig-
nal when the outputs are inhibited due to the con-
troller keylock switch position or by an External
Reset/Inhibit switch input.
Fault Output - The R7494/C7052J system provides
the Automatic oifeature for continuously checking
the cleanliness of the viewing window and the sensi-
tivity of the sensor. In addition, automatic diagnostic
circuitry in the controller monitors the system for
wiring continuity faults as well as other malfunctions
that could prevent the system from responding in the
event of a fire. If a fault is detected:
1. A normally energized solid state Fault output is
de-energized. This provides a means of control
for an external fault annunciation device (if used).
2. A FAULT LED on the front panel of the controller
is illuminated to provide a visual indication that a
system fault has occurred.
6
MASTER
IN OUT
SLAVE CONTROLLERS
IN OUT IN OUT IN OUT IN OUT IN OUT IN OUT IN OUT
NUMBER 1 NUMBER 2 NUMBER 3 NUMBER 4 NUMBER 5 NUMBER 6 NUMBER 7 NUMBER 8
A1460
Figure 5—Intercontroller Communications
Figure 4—Open Controller Outputs with Transient
Suppression Device Connected
100K
CONTROLLER
OPEN COLLECTOR OUTPUT
1N4004
TYPICAL
+60 VDC MAXIMUM
A1459

3. The STATUS display uses numerical code to indi-
cate the nature of the fault. (see Table 1).
4. The ZONE display uses numerical code to indi-
cate the detector/zone affected (if applicable).
External Accept - Connecting a switch between termi-
nal 47 and circuit ground (terminal 2) allows remote
de-activation of the alarm output without interrupting
the Zone or Fire Logic outputs.
Status and Detector Outputs - Provide binary output
representations of the front panel digital displays for
remote indication of zone, detector and system status
(indicators not provided).
FIELD WIRING CONNECTOR
The R7494 Controller is typically furnished with a field
wiring connector backplate that incorporates pres-
sure type screw terminals for connecting the external
wiring and two circuit board edge connectors for
attaching to the controller. The R7494 controller is
available without a backplate when used with the
R6007 Relay Module. The use of a Q4004 Mounting
Cage is recommended for mounting the controller.
The backplate is attached to the rear of the cage to
allow easy removal of the controller without disturbing
the wiring. The controller is designed for installation
in a non-hazardous area.
SPECIFICATIONS
SPECTRAL SENSITIVITY RANGE—
UV: The UV sensor responds to radiation over the
range of 0.185 to 0.245 microns (1850 to 2450
angstroms).
IR: The single frequency infrared sensor responds to
radiation between 4.2 and 4.7 microns.
Figure1 illustrates the spectral response range of the
UV and IR sensors.
CONE OF VISION—
The C7052J has a 80 degree cone of vision with the
highest sensitivity lying along its central axis. See
Figure 6.
FLAME SENSITIVITY—
The C7052J5 with a part number DE5500 IR Sensor
Module (the sensor part number is printed on its side)
detects a 1 foot by 1 foot gasoline fire at 50 feet, a 2
foot by 2 foot JP4 fire at 100 feet and a 10 foot by 10
foot JP4 fire at 150 feet.
The C7052J with a part number DE3895 IR Sensor
Module (the sensor part number is printed on its side)
detects a 1 foot by 1 foot gasoline fire at 35 to 45 feet,
a 2 foot by 2 foot JP4 fire at 100 feet and a 10 foot by
10 foot JP4 fire at 150 feet.
RESPONSE TIME—
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. With typi-
cal controller settings of 0.25 second gate length, 4
counts per gate, and 4 consecutive gates, the system
will respond to an intense fire signal in less than 2
seconds.
Response times of less than 1 second to an intense
fire signal can be achieved by setting the controller
for a 0.125 second gate length, 2 counts per gate,
and 3 consecutive gates.
INPUT VOLTAGE—
Controller and Detector
24 vdc nominal (18 vdc minimum, 32 vdc maximum)
with less than 1 volt of ripple.
POWER CONSUMPTION—
Controller: 1.5 watts typical, 3.5 watts maximum.
Detector: 1.0 watt typical, 3.5 watts maximum
(C7052J5 series: 5 watts maximum).
OUTPUT CIRCUIT RATINGS—
Open collector transistor outputs on the controller are
rated 100 ma dc, not to exceed 60 vdc. An internal
100 kilohm resistor is connected from the output to
circuit ground (terminal 2). External equipment that
may generate transients when switching (such as
relays) should have a transient suppression device
connected across the coil at the time of installation.
This will safeguard the output transistors in the con-
troller from possible damage. See Figure 4.
7 95-8311
0°
15°
30°
45°
15°
30°
45°
A1461
100
90
80
70
60
50
40
30
20
10
DETECTION
DISTANCE
(PERCENT)
100% REPRESENTS THE MAXIMUM DETECTION DISTANCE FOR A
GIVEN FIRE. THE SENSITIVITY INCREASES AS THE ANGLE OF
INCIDENCE DECREASES.
Figure 6—Cone of Vision

CONTROLLER TEMPERATURE RANGE—
Operating: –40°F to +158°F (–40°C to +70°C)
Storage: –67°F to +170°F (–55°C to +77°C)
DETECTOR TEMPERATURE RANGE—
Operating: –40°F to +167°F (–40°C to +75°C).
Storage: –67°F to +185°F (–55°C to +85°C)
DETECTOR HUMIDITY RANGE—
0 to 95% relative humidity.
RFI/EMI HARDENED—
Detector designed to meet RFI and EMI immunity
requirements of MIL STD 461, 462 and 463.
DETECTOR ENCLOSURE MATERIAL—
Copper-free aluminum (red) or 316 stainless steel,
with optional stainless steel mounting bracket.
DETECTOR ENCLOSURE RATINGS—
FM approved explosion-proof for Class I, Div. 1,
Groups B, C and D, Class II, Div. 1, Groups E, F and
G. CSA certified explosion-proof for Class I, Div. 1,
Groups C and D, Class II, Div. 1, Groups E, F and G.
BASEEFA/CENELEC certified flame-proof for EEX d
IIB T6. NEMA 4/IP66 enclosure rating.
DIMENSIONS—
See Figures 7, 8, 12 and 13.
SHIPPING WEIGHT—
R7494 Controller
4.4 pounds (2.0 kilograms)
C7052J Detector
Aluminum: 6.0 pounds (2.7 kilograms)
Stainless Steel: 14.0 pounds (6.4 kilograms)
8
C1047
3.38 (85.8 MM) 7.11 (181 MM)
7.81
(198 MM)
2.5 DIA.
(64 MM)
5.25
(133 MM)
CONDUIT ENTRY 3/4 NPT OR 25 MM
9.5 (242 MM)
7.0
(177 MM)
2.0
(50MM)
F234
Figure 8—Dimensions of R7494 Controller in Inches (Millimeters)
Figure 7—Detector Dimensions in Inches (Millimeters)