Det-Tronics R7404 User manual

Instructions 95-8242
Ultraviolet Flame Detection System
R7404 Controller
C7050 Detector
7.1 Rev: 11/10 95-8242

Table Of Contents
SYSTEM APPLICATION ..................................................... 1
FEATURES ......................................................................... 2
GENERAL APPLICATION INFORMATION......................... 2
SYSTEM DESCRIPTION.................................................... 3
Detector......................................................................... 3
Controller....................................................................... 3
SPECIFICATIONS .............................................................. 5
DETECTOR SENSITIVITY ................................................. 8
SYSTEM SENSITIVITY CONSIDERATIONS...................... 9
INSTALLATION..................................................................10
Wiring Requirements....................................................10
Detector Positioning and Density................................. 11
Mounting the Detector..................................................11
Controller......................................................................13
TYPICAL SYSTEM APPLICATIONS..................................17
STARTUP PROCEDURE...................................................18
CHECKOUT PROCEDURE ...............................................20
Manual oiCheck......................................................... 20
Detector Count Test..................................................... 20
Manual Check in Normal Mode .................................. 21
MAINTENANCE.................................................................21
TROUBLESHOOTING...................................................... 22
DEVICE REPAIR AND RETURN...................................... 22
ORDERING INFORMATION..............................................24
Options........................................................................ 24
Recommended Spare Parts........................................ 24

NOTE
Not compliant to FM 3260 (2000).
SYSTEM APPLICATION
The Det-Tronics model R7404 Controller and C7050
Detector provide fast, reliable flame detection in a wide
variety of applications. The microprocessor based
controller simultaneously monitors up to 16 C7050
ultraviolet (UV) detectors in up to 8 different zones. The
system uses the Automatic Optical Integrity (oi) feature,
which provides a continuous check of detector optical
surfaces, detector sensitivity, and electronic circuitry of
the detector/controller system. Also included is automatic
fault identification, which monitors the system for proper
operation, and provides a digital display of system status
using a numerical code. Other features include individual
zone identification and “voting” capability, as well as
manual oitesting.
The C7050 Detector responds instantly to the ultraviolet
radiation that is emitted by a flame. It is designed for use
in hazardous locations and is particularly suitable for use
in outdoor applications because it is not affected by wind
or rain, and is insensitive to solar radiation. In addition,
the detector does not respond to normal artificial light.
Typical applications for Det-Tronics UV detection systems
are:
— Wherever highly combustible materials are involved
— Where there is a need for instantaneous response to
flame
— Wherever unsupervised areas require automated fire
protection
— Where there is a large capital investment to be
protected.
Examples of actual installations using the Det-Tronics UV
detector in automated fire protection systems include:
Petroleum Products
— Gasoline transport loading terminals
— Offshore drilling and production platforms
— Pipeline pumping stations
— Tank farms
— Refineries
— Marine engine rooms
— Jet engine test cells
Gaseous Fuels
— Butane and propane loading and storage
— Pipeline compressor stations
— Gas gathering facilities
— Pipelines in highly populated areas
— LNG loading, transfer and storage facilities
— Hydrogen and ammonia production and refinery
reformers
— Gas turbines
7.1 ©Detector Electronics Corporation 2010 Rev: 11/10 95-8242
Ultraviolet Flame Detection System
R7404 Controller
C7050 Detector
INSTRUCTIONS

7.1 2 95-8242
Solid Materials
— Munitions production such as illuminating flare
material, TNT, and other propellants
— Powder coating booths
Other Processes
— Paint Spray booths
— Chemical and Petrochemical production
Information on these and a wide variety of applications is
available from Detector Electronics.
FEATURES
•Instantaneousresponsetoultravioletradiation.
•Detectors operate under adverse weather conditions
such as wind, rain, snow, high humidity, and extremes
of temperature or pressure.
•AutomaticOpticalIntegrity.
•Adjustablesensitivityandtimedelay.
•Allautomatictestfunctionsperformedwiththesystem
on line.
•Manual oitest capability (in addition to Automatic oi
capability).
•Automaticfaultidentication.
•Individualzoneidenticationwitheightvotingoptions.
•Microprocessorcontrol.
•Latching ZONE LEDs identify the zone responding to
fire.
•Output circuits can be made latching or non-latching
througheldadjustment.
•Individualdetectoroutput(countrate)canbemeasured
and observed on the digital display.
•DigitaldisplayofbackgroundUVsignalsinTestmode.
•Digital display signal output available at eld wiring
terminals for interfacing with computers or other
equipment.
•Detector is Factory Mutual (FM) approved, Canadian
StandardsAssociation(CSA)certied,andBASEEFA/
CENELEC certified.
GENERAL APPLICATION
INFORMATION
In applying any type of sensing device as a fire detector,
it is important to know of any conditions that may prevent
the device from responding to a fire, and also to know
what other sources besides fire will cause the device
to respond. A UV detector is useful in fire protection
applications because it will provide very fast response to
the presence of ultraviolet radiation emitted by a flame.
In addition, it is not affected by environmental conditions
such as wind, rain, or extremes of temperature and
pressure. The Det-Tronics UV system is also insensitive
to the ultraviolet component of solar radiation.
Considering the above, it can be seen that there are fire
detection applications where only ultraviolet sensors are
suitable. However, success in using an ultraviolet detector
is dependent not only on knowing its advantages, but
also its limitations. It is important to note that electric
arc welding is a source of intense ultraviolet radiation,
and care must be taken to ensure that arc welding is not
performed in protected areas without securing the system.
In addition, UV detectors should not be positioned so that
their cone of vision can scan the horizon. Rather, they
should be directed down over the designated hazardous
area to reduce the likelihood of picking up UV radiation
from distant sources.
An important fact regarding radiation detectors of any
type is that the radiation must reach the detectors in
order for them to respond. Care must be taken to keep
obstructions out of the line of view.  For an ultraviolet
detector, this means that ultraviolet absorbing gases
or vapors as well as physical obstructions must not be
allowed to come between the detector and the protected
hazard. Smoke will absorb ultraviolet radiation, and
if accumulations of dense smoke can be expected to
precede the presence of flame, then UV detectors that
are used in enclosed areas should be mounted on the wall
approximately 3 feet (1 meter) from the ceiling where the
accumulation of smoke is reduced. Glass and plexiglass
windows also significantly attenuate UV radiation and
must not be located between the detector and a potential
flame source. If the window cannot be eliminated or the
detector location changed, contact Detector Electronics
for recommendations regarding window materials that will
not attenuate UV radiation.
It must be noted that malfunctions can occur in any type
of equipment, and although Det-Tronics systems are
subjectedtorigoroustestsbeforeshipment,nowayhas
yet been found to guarantee that every device will always
operate perfectly. The highest reliability with regard to
response to a fire is achieved when a hazardous area is
supervised by more than one detector, and when each
detector can independently register an alarm.

7.1 3 95-8242
SYSTEM DESCRIPTION
The R7404/C7050 UV detection system consists of an
R7404 Controller and up to 16 C7050 Detectors.
DETECTOR
The C7050 Detector responds to UV radiation over the
range of 1850 to 2450 angstroms. It is insensitive to direct
or reflected sunlight and to normal artificial lighting.
The output of the detector consists of a series of voltage
pulses or “counts.” The frequency of these pulses is
directly proportional to the intensity of the radiation being
detected and is measured in counts per second (cps).
Oi
The detector is equipped with the Automatic oifeature
(Figure 1).  A UV test lamp is mounted in the same
enclosure with the UV sensor tube, but they are optically
isolated from each other by a cylindrical shield. When
the test lamp is actuated by a signal from the controller,
it generates a UV test signal that travels out through the
viewing window, where it encounters the reflective oiring
and is directed back through the window to the sensor.
The controller evaluates the strength of the return signal
to determine the relative condition of the detector and
its optical surfaces. Since this UV test signal must pass
through the same portion of the viewing window as UV
radiation generated by a flame, a reliable test of the ability
of the detector to “see” a fire is achieved.
The controller continuously executes the automatic oi
test, sequentially testing each detector connected to it. If
a fault should occur in the system, it is quickly detected
and registered on the digital display on the front panel of
thecontrollerandtheFaultoutputisde-energized.
Internal Reection oi
The use of an Internal Reflection oidetector is
recommended in applications where corrosive or oily
contaminants are present in the atmosphere. This type
of environment can cause rapid deterioration of the
reflectivity of externally mounted oirings, resulting in
the need for frequent detector maintenance. Since the
Internal Reflection detector checks the cleanliness of the
viewing window without the use of an external reflective
oiring, faults caused by corrosion or contamination of
the ring are eliminated. A fault will be indicated only if the
viewing window is actually dirty. It is important to note
that the internal reflection system is effective only with oily
substances that wet the surface of the window. It does not
detect dry contaminants and, therefore, is not practical
for powder coating booths or similar applications where
various dry contaminants can obscure the vision of the
detector.
UV detectors that are currently using the external
reflection oisystem can easily be converted to Internal
Reflection in the field by simply replacing the existing
sensor tube module with a DE1888V Internal Reflection
oiTubeModule.Nocalibrationorotheradjustmentsare
required, and no modifications to the detector enclosure
are needed.
Detector Enclosure
The detector is housed in an explosion-proof enclosure
that is designed to meet most national and international
standards. It is available in various materials to meet
the requirements of the environment in which it is used.
Materials include anodized aluminum, nickel-plated brass
and 316 stainless steel. The aluminum and the nickel-
plated brass housings are epoxy coated, making them
suitable for use in high saline atmospheres, such as
offshore platforms.
The detector is typically mounted on an optional
swivel mounting assembly (Model Q9001), which is
recommended for ease in installation. Other mounting
arrangements are also available, such as a quick-
connect front mount for applications involving paint spray
or powder coating booths, or for looking inside mixers,
kettles, conveyors and other inaccessible areas.
CONTROLLER
The R7404 is designed for use with 24 volt dc power
supplies, but will operate from any direct current supply
between 10 and 38 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 R7404 Controller, it is indicated by a continuously
energized green LED. All other lights and displays on
the R7404 panel are normally off, but may be periodically
UV DETECTOR
UV TEST LAMP
OPTICAL SHIELD
VIEWING WINDOW
SNAP-IN oiRING
UV SENSOR
C784
Figure 1—Detector with oi

7.1 4 95-8242
checked for operation by pressing the LAMP TEST button
located directly opposite the POWER light as illustrated in
Figure2.Itisnotnecessaryforthecontrollertobeinthe
TEST mode when this check is performed.
The R7404 Controller incorporates a microprocessor and
a programmable-read-only-memory (PROM) to store
and implement the permanent program for operating
the system. The main loop of the operating program
continuously cycles through the Automatic Optical
Integrity test, checking each detector and its wiring. At
the same time, the microprocessor can be interrupted by
any one of several status changes, such as a fault, a “fire”
signal from one of the detection zones, or a change in
the setting of the keylock switch. In the event of a status
change, the microprocessor will take the appropriate
action.
NOTE
TheR7404isavailablewithvariousoptionaloperating
programs (STAR Logic, Remote Surveillance, etc.).
This manual covers the operation of the R7404 with
the standard program. Always refer to the manual
supplied with any special purpose controllers when
operating or installing the equipment.
Fire Response
When the controller receives a “fire” signal from any
detector in the system, it is compared to the stored
information of the program. If the signal frequency is lower
than the programmed setting for sensitivity, the lower
display on the front panel of the controller responds with a
“3” and the upper display identifies the first zone affected.
If the signal frequency is greater than the programmed
sensitivity setting for a period greater than the preset time
delay, the following actions take place:
1. The appropriate solid state zone output(s) is energized.
One zone output is available for each of the eight
zones.
2. The solid state alarm output is energized. The alarm
output is activated when any zone detects a fire.
3. TheZONEdisplayidentiestherstrespondingzone.
The DETECTOR display is blank.
4. The SYSTEM STATUS display shows a “6”, indicating
fire.
5. OneormoreZONELEDsturnon(blinking),indicating
the zone(s) detecting UV radiation.
6. If the selected “voting” criteria has been satisfied, the
appropriate Fire Logic output is energized, and the
corresponding LED is on.
NOTE
When a re signal is no longer present, the ZONE
LED(s) and the display indication will latch until
manually reset (ZONE LED emits steady light). The
display latch feature is useful in post-re analysis as
a means of determining re origin.
The Alarm output is typically used to actuate an external
audible alarm when a fire signal is received from one or
more detectors. Since these alarms can be disruptive to
personnel who are responding to the fire emergency, a
means for alarm silencing has been provided. The R7404
is equipped with a TEST/ACCEPT button, which will de-
activatethealarmcircuitwithoutinterruptingtheZoneand
FireLogicoutputs.Thealarmcanalsobesilencedbyan
optional external silence switch (see “Typical Applications”
section).
NOTE
If the system is going to be put out of service for
periods of time, use the Test/accept to bypass
the alarm contacts instead of shutting down the
system. This will provide optimum performance
when reconnected.
E0235
RED LEDS
RED LEDS
KEYLOCK SWITCH
LAMP TEST
TEST/ACCEPT
AMBER LED
DETECTOR SELECTION
AMBER LED
GREEN LED
Figure 2—Front Panel of R7404

7.1 5 95-8242
Digital Displays
The upper digital display on the R7404 panel identifies
both the detector and zone involved in any “System
Status”occurrence.Forexample,withthekeylockswitch
in the TEST position, and a “1” digit showing on the lower
display, the upper display shows which detector and zone
is electrically positioned for a manual oitest.
Voting Logic
The R7404 permits two groups of four zones each to “vote”
separately, or eight zones to “vote” together. This means
that the controller can be programmed to require more
thanonedetectortobeactuatedbeforetheFireLogicA
and/or B outputs are energized. The Det-Tronics “voting”
principle allows combinations of detectors to fulfill voting
requirements, and represents the best balance between
reliability of fire detection and freedom from false actuation
due to individual detector malfunction.
Fault Identication
The automatic fault identification feature of the R7404
operates much the same as on other Det-Tronics
equipment, but has expanded capability. The lower
display on the controller panel identifies the probable
source or type of fault using a numerical code. A summary
of the R7404 system status code is shown in Table 1.
System Reset
The reset function is incorporated in a rotary keylock
switch, which has three positions: (1) NORMAL, (2) RESET
and (3) TEST. The switch sequence is such that a return
to NORMAL from the TEST position can be achieved
only by passing through the RESET mode (Figure 2).
The reset function may also be performed by an optional
external reset switch. Whenever the keylock switch is
placed in the RESET or TEST position, the FAULT and
INHIBITLEDswillturnon,andallZone,FireLogic,and
Alarm outputs will be disabled.
Programming Switches
The circuit board on the left side of the R7404 Controller
contains switches for selection of:
1. Detectors connected to the controller
2. System sensitivity
3. Time delay
4. Firelogicandlatching/non-latchingoptions.
See “Switch Setting Procedure” in the “Installation” section
for a detailed description.
SPECIFICATIONS
SPECTRAL SENSITIVITY RANGE—
The detector is solar blind and responds to UV radiation
over the range of 185 to 245 nanometers (1850 to 2450
angstroms).
SYSTEM SENSITIVITY—
Sensitivity for the standard R7404 Controller is field
adjustable over a range of 8 through 120 counts per
second (cps) in increments of 8 cps (24 cps setting is
factory recommended). The maximum response distance
isachievedatan8cpssensitivitysetting.Forapplications
involving high background radiation potential, the system
can be desensitized by increasing the count rate required
to actuate it. The 120 cps setting results in the minimum
response distance.
INPUT VOLTAGE—
The R7404 can operate from any voltage in the range of
18 to 38 volts dc.
TEMPERATURE RATING—
Operating:
 Standarddetector: –40°Fto+167°F(–40°Cto+75°C).
 Controller: –40°Fto+158°F(–40°Cto+70°C).
Detectors with higher temperature ratings are available.
Storage:
Detector and controller:
  –67°Fto+167°F(–55°Cto+75°C).
HUMIDITY—
0 to 95% RH, non-condensing.
0 — Keylock switch in RESET position, or external
Inhibit/Reset is activated.
1 — Keylock switch in TEST position.
2 — Reduced detector sensitivity (
oi fault) or faulty
wiring.
3 — Spurious UV detection or over sensitive detector.
4 — Low +290 vdc
(+290 volt detector supply wire may be shorted).
5 — High +290 vdc
(voltage regulation failure in the 290 volt supply).
6 — Fire.
7 — Not used.
8 — Controller in count test mode.
Table 1—System Status Codes

7.1 6 95-8242
RESPONSE TIME—
Response to a saturating (high intensity) UV source is
typically 10 milliseconds for the zone and alarm outputs
and 150 milliseconds for the fire logic outputs when
sensitivity is set for 8 cps and time delay is set for 0
seconds.
OUTPUT CIRCUIT RATINGS—
Open collector solid state output is rated 100 milliamperes
dc at 60 volts dc. Lead monitoring is provided by an
internal 100 kilohm resistor from output to ground. External
equipment that can generate transients when switching
(such as relays) must have a transient suppression device
(diode) connected across the coil at the time of installation
to safeguard the output transistors against possible
damage. See the “Installation” section for details.
POWER CONSUMPTION (Controller and 16 Detectors)—
Standby: 1.5 watts typical, 1.7 watts maximum.
Fire: 15wattstypical,16.5wattsmaximum.
WIRING REQUIREMENTS—
The detector wiring must be a minimum of 22 gauge with
a minimum voltage rating of 600 volts rms. (22 gauge
copper wire has a diameter of 0.6439 mm or 0.02535
inch. Its cross section is 0.3255 mm2or 0.0005 in2. Its
resistance is 16.14 ohm/1000 ft. or 53.0 ohm/km.) The
R7404 Controller will accommodate up to 16 detectors.
The detectors can be located up to 2000 feet (600
meters) from the controller. Shielded cable is required
for the “B” (signal) leadwires. As with any field device,
shielded cable on all wires provides maximum protection
fromRFI/EMIsources.
SHIPPING WEIGHT (APPROXIMATE)—
Pounds Kilograms
Controller 2.5 1.12
Detector (aluminum) 1.25 0.56
(stainless steel or brass) 2.25 1.0
DIMENSIONS—
Refer to Figure 3 for dimensions of the controller and
Figure4 for the detectorand swivel mountingbrackets.
Figure 5 shows the dimensions of the Q4004 Mounting
Cage. Cages that hold fewer devices are also available.
CONE OF VISION—
The C7050 Detector has a nominal 90 degree cone of
vision with the highest sensitivity along its central axis.
SeeFigure7.
DETECTOR ENCLOSURE MATERIALS—
Models are available in anodized copper-free aluminum,
nickel-plated brass, or 316 stainless steel.
9.5 (242 MM)
7.0
(177 MM)
2.0
(50MM)
F234
Figure 3—Controller Dimensions in Inches (Millimeters)
POSITIONING SWIVEL NUT

0.25 (6.4 MM) DIAMETER (3)

DETECTOR HOUSING
2-1/2 (64 MM) DIAMETER
TERMINAL CAP
2.00 (50.8 MM) DIAMETER

1/2 – 14 NPT
3/4 – 14 NPT
M20 x 1.5 
M25 x 1.5 – 6H
Pg 16

5/16 – 18 UNC – 2A

DETECTOR LOCK NUT

CONDUIT OPTIONS:

OPTIONAL SWIVEL
MOUNTING BRACKET
(Q9001B, FOR ALUMINUM ONLY)
120 o± 2o(2)

45 o(2)
2-1/2
(64 MM)

2-1/2
(64 MM)

4-3/4
(121 MM)
G0 121
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 TO SWIVEL MOUNT
B1323
Q9001H – USE FOR MOUNTING NICKEL/BRASS
AND STAINLESS STEEL C7050 DETECTORS
Figure 4—Detector Dimensions in Inches (Millimeters)

7.1 7 95-8242
CERTIFICATIONS—
FMR: SeeAppendixAfordetails.
CSA: Explosion-proof for Class I, Division 1,
Groups C and D.
Dust ignition-proof for Class II, Division 1,
GroupsE,F,andG.
Enclosure Type 4 (Indoor and Outdoor
Use)
CSFM: Explosion-proofforClassI,Division1,
Groups B, C and D.
Dust ignition-proof for Class II, Division 1,
GroupsE,F,andG.
CENELEC: EExdIIB+H2T6(Tamb=–40°Cto+77°C)
EExdIIB+H2T4(Tamb=–40°Cto+125°C)
IP66
Special Conditions for Safe Use “X”:
The fused silica window is liable to be
damaged by impact. The detector should
be installed in such a manner as to prevent
the window from receiving mechanical
damage.
Russian PerformanceVeriedfrom–55°Cto+75°C
Certication: 1ExdIIBT6X(Tamb=–40°Cto+77°C)
1ExdIIBT4/H2X(Tamb=–40°Cto+125°C)
IP66
(A)
(B)
(C)
1.48 (37.59)
(D)
B1475
ALL CONTROLLER CAGES REQUIRE
A MINIMUM OF 10.12 INCHES (257.1 MM)
DEPTH CLEARANCE

(E)
RACK PA RT NUMBER CONTROLLER
TYPE 005269-XXX POSITIONS FOR: HT:DIM. (A) DIM. (B)DIM. (C)DIM. (D) DIM. (E)WEIGHT
FIRE GAS INCH MM INCH MM INCH MM INCH MM INCH MM LB KG
4U –001 8164U 19.00 482.6 18.30 464.8 17.36 440.9 4.00 101.6 6.97 177.1 9.3 4.2
4U –002 6124U 15.06 382.6 14.36 364.7 13.42 340.9 7.6 3.5
4U –003 484U 11.13 282.6 10.43 264.9 9.49 241.1 5.9 2.7
4U –004 364U 9.16 232.7 8.46 214.9 7.52 191.0 5.1 2.3
4U –005 244U 7.19 182.7 6.49 164.9 5.55 141.0 4.2 1.9
4U –006 124U 5.22 132.6 4.52 114.8 3.58 90.9 3.1 1.4
3U –007 16 3U 19.00 482.6 18.30 464.8 17.36 440.9 2.25 57.15 5.22 132.6 9.3 4.2
3U –008 12 3U 15.06 382.6 14.36 364.7 13.42 340.9 7.6 3.5
3U –008 83U 11.13 282.6 10.43 264.9 9.49 241.1 5.9 2.7
3U –010 63U 9.16 232.7 8.46 214.9 7.52 191.0 5.1 2.3
3U –011 43U 7.19 182.7 6.49 164.9 5.55 141.0 4.2 1.9
3U –012 23U 5.22 132.6 4.52 114.8 3.58 90.9 3.1 1.4
Figure 5—Q4004 Mounting Cage Dimensions in Inches (Millimeters)
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
A1898
Figure 6—Detector Range of Sensitivity

7.1 8 95-8242
DETECTOR SENSITIVITY
The UV flame detector responds to radiation over
wavelengths of 185 to 245 nanometers (1850 to 2450
angstroms).  Figure 6 illustrates the range of sensitivity,
and compares this range to other forms of radiation. Note
that UV radiation reaching the earth from the sun does
not extend into the region of sensitivity of the detector.
In addition, radiation from normal artificial lighting, such
as fluorescent, mercury vapor, and incandescent lamps
does not extend into the detector’s spectral range. As a
result, the detector is solar blind and insensitive to these
forms of radiation and may be used outdoors or indoors.
NOTE
Some mercury vapor lamps can operate for
extended periods with cracked or otherwise
damaged envelopes, and will then emit UV
radiation in the frequency response range of the
detector. Defective mercury vapor lamps should
be immediately removed from service.
The UV sensor responds to any radiation that can
penetrate its glass envelope and create ion pairs. The
glass envelope absorbs most alpha or beta particles,
but it permits both gamma and x-rays to pass through. If
these rays create ion pairs between the electrodes near
the cathode, the normal discharge process will occur and
the detector will produce a count. If the x- or gamma ray
flux is sufficient to produce a count rate higher than the
system sensitivity setting, an undesired response of the
system can occur.
Data on sensitivity of the C7050 Detector to various x-ray
and gamma radiation intensities is impossible to relate
to a typical detector exposure. The normal precaution
against false actuation due to x-rays or gamma radiation
is to turn off the detection system when sources of high
level radiation are being used in the immediate area.
Caution must be exercised if the detection system is
turned off, since the hazardous area will not be protected.
If the application requires continuous supervision by the
detection system, a “Nuclear Surveillance” system is
needed. Refer to form number 95-8256 or contact Det-
Tronics for complete information.
NOTE
Ultraviolet detectors are very sensitivetoarc welding,
and if this type of radiation can be expected, it
must be controlled through proper application.
Successful application techniques include careful
positioning and shielding of the detectors. Some
applications can require a “Remote Surveillance”
or UV/IR system. Contact the Field Support Group
at Detector Electronics for complete information.
Figure 7 shows a composite view of the cone of vision
and the response of a typical detector to a constant UV
source at various relative distances. Depending upon the
intensity of the ultraviolet radiation source, the C7050 can
be considered to have a practical application distance of
up to about 50 feet (15 meters). Under certain controlled
conditions, detectors can be used at greater distances.
0°
15°
30°
45°
15°
30°
45°
VIEWING ANGLE
A1288
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 7—Detector Cone of Vision
260
240
220
200
180
160
140
120
100
80
60
40
20
00 10 20 30 40 50 60 70 80 90 100
0 5 10 15 20 25 30
1 (0.09) 2 (0.18) 6 (0.56) 8 (0.74) 10 (0.93) 12 (1.11) 14 (1.3)
36 (3.3)
4 (0.37)
DETECTOR OUTPUT VERSUS DISTANCE
FROM A GASOLINE FIRE AS A FUNCTION
OF SURFACE AREA OF THE SOURCE
DETECTOR OUTPUT – COUNTS PER SECOND
DISTANCE
FEET
METERS
A1487
SQUARE FEET (SQUARE METERS)
Figure 8—Sensitivity of a Typical Detector to a Gasoline Reference Fire

7.1 9 95-8242
SYSTEM SENSITIVITY CONSIDERATIONS
Figure8showstheapproximaterelationbetweencounts
per second (cps) and distance.  From this curve it can
be seen, for example, that a 4 ft2 (0.37 m2) gasoline fire
at 60 feet (18 meters) will normally cause the detector to
generate 20 cps. The same fire at 40 feet (12 meters) will
generate about 50 cps. If a 2 ft2 (0.18 m2) fire at 20 feet
(6 meters) will generate about 100 cps, the same fire at
70 feet (21 meters) will generate about 8 cps. Because
of the complexity of the combustion process, the UV
tube count rate generated by different size fires viewed
from the same distance is difficult to predict with a high
degree of precision. In general, however, if a fire doubles
in size, the tube count rate is increased by approximately
60 percent.
NOTE
The count rate of any given detector will depend
upon the sensitivity of the sensor tube, the type
and amount of fuel, the distance between the
detector and the re, as well as various other
factors. Figure 8 illustrates the relative response
of a “typical” C7050 to various size gasoline res
based on minimum sensitivity standards for DE1888
UV sensor modules. Sensor modules with higher
sensitivity are available. Consult the Field Support
Group at Det-Tronics for information or assistance
concerning a specic detector tube type or a
specic combustible material.
Selection of controller sensitivity and time delay to be
used in a given application is dependent on the level of
hazard present and the action to be taken in the event
of re.  The adjustable sensitivity and time delay of the
R7404 allows it to meet the requirements of virtually any
application.
Thesystemcanbeadjustedtovarioussensitivitylevels
by programming the controller to respond at a pre-
determined detector tube count rate. This count rate is
dependent upon the intensity of the ultraviolet radiation
reaching the detector, which is a function of fuel, flame
size, distance from the detector, and the amount of UV
absorbing vapors that may be present.
Programming the controller to respond to a low count
rate results in high system sensitivity. Conversely,
programming the controller to require a high count rate
results in low system sensitivity. The presence of UV
absorbing vapors must be examined closely. Some
chemical and petrochemical vapors have very strong UV
absorption characteristics. See Table 2.
Referring to Figure 8 and considering the conditions
described above, the criteria for selecting a correct system
sensitivityadjustmentcanbeestablished.Forexample,
assume that the hazard to be protected is at a distance
of 23 feet (7 meters) from the detector. Assume that the
hazard is gasoline and that it is desired to produce an
alarm signal when a fire with a surface area of 1 square
foot (0.09 m2) develops. Reading on the horizontal
“Distance” axis of Figure 8, locate the vertical line at
approximately23feet(7meters).Followthislineuntilit
intersects the “1 square foot” curve. Note that this occurs
at the horizontal line of about 50 counts per second on
the vertical “Detector Output” axis. This means that the
controller should be adjusted to 48 cps sensitivity in
order to detect this size fire from 23 feet (7 meters). If the
detectors were located 30 feet from the hazard, it can be
seen that it would be necessary to use a more sensitive
(lower cps) setting.
The following 38 substances exhibit signicant UV
absorption characteristics. These are also generally
hazardous vapors. While generally of little consequence
in small amounts, these gases can restrict UV detection
if they are in the atmosphere in heavy concentrations. It
should also be determined whether or not large amounts of
these gases may be released as a result of a re-causing
occurrence.
Acetaldehyde Methyl Methacrylate
Acetone Alpha-Methylstyrene
Acrylonitrile Naphthalene
Ethyl Acrylate Nitroethane
Methyl Acrylate Nitrobenzene
Ethanol Nitromethane
Ammonia 1-Nitropropane
Aniline 2-Nitropropane
Benzene 2-Pentanone
1,3 Butadiene Phenol
2—Butanone Phenyl Clycide Ether
Butylamine Pyridine
Chlorobenzene Hydrogen Sulde
1-Chloro-1-Nitropropane Styrene
Chloroprene Tetrachloroethylene
Cumene Toluene
Cyclopentadiene Trichloroethylene
O-Dichlorobenzene Vinyl Toluene
P-Dichlorobenzene Xylene
If UV-absorbing gases may be a factor in a given application,
precautionary measures should be taken. Detectors can
be placed closer to the potential hazard area, and/or
the sensitivity of the detection system can be increased.
Contact the factory for further details.
Substances such as methane, propane, butane, hexane,
camphor and octane are not UV absorbing.
Table 2—UV Absorbing Gases and Vapors

7.1 10 95-8242
INSTALLATION
IMPORTANT
The installation procedure described in this
manual is intended for wiring and programming
the standard R7404 Controller used with the
C7050B Detector. It is important to note that the
R7404 Controller is available with various operating
programs (EPROMs). This can affect the system
programming and/or terminal conguration of the
controller. Since the installation procedure and
application instructions vary with each model,
specic information is supplied in a separate manual
that is specic to the equipment being installed.
When installing any “special purpose” version of
the R7404 Controller, always use the manual that is
supplied with the controller in conjunction with this
manual. If a conict arises, follow the procedure in
the manual for the specic equipment involved.
Device Manual Form Number
R7404 with STAR Logic 95-8294
R7404 for Remote Surveillance System 95-8249
R7404 for Nuclear Surveillance System 95-8256
WIRING REQUIREMENTS
The wiring to the detector must be a shielded cable 22
gauge (0.643 mm diameter) minimum, with at least a
600 volt rms rating. If there are two detectors in a zone,
they may share a cable. If the detector leads are run in
conduit, the conduit must not be used for wiring from
other electrical equipment. Detectors can be located up
to 2000 feet (600 meters) from the controller.
Shielded cable is required for the “B” (signal) leadwires.
As with any field device, shielded cable for all wires
providesmaximumprotectionfromRFI/EMIsources.In
applications where the wiring cable is installed in conduit,
the conduit must not be used for wiring to other electrical
equipment.
Since moisture can be detrimental to electronic devices,
it is important that moisture not be allowed to come in
contact with the electrical connections of the system.
Moisture in the air can be trapped within sections of
conduit, therefore the use of conduit seals is required
to prevent damage to electrical connections caused by
condensation within the conduit. These seals must be
water-tight and explosion-proof and are to be installed
even if they are not required by local wiring codes. A seal
must be located as close to the detector as possible. In no
case should this seal be located more than 18 inches (46
cm) from the detector. If a conduit swivel is used, a seal
must be located between the detector and the swivel.
When local codes require an explosion-proof installation,
an additional seal is also required at any point where the
conduit enters a non-hazardous area.
When pouring a seal, the use of a fiberdam is required
to assure proper formation of the seal. The seals should
never be poured in temperatures that are below freezing,
since the water in the sealing compound will freeze and the
compound will not dry properly. Contamination problems
can then result when temperatures rise above the freezing
point and the compound thaws. The shielding of the cable
should be stripped back to permit the seal to form around
the individual leads, rather than around the outside of the
shield. This will prevent any siphoning action that might
occur through the inside of the shield.
It is recommended that conduit breathers also be used.
In some applications, alternate changes in temperature
and barometric pressure can cause “breathing,” which
allows the entry and circulation of moist air throughout the
detector and connected conduit. Joints in the conduit
system and its components are seldom tight enough the
prevent this “breathing.” Moisture in the air can condense
at the base of vertical conduit runs and equipment
enclosures, and can build up over a period of time. This
can be detrimental to electronic devices. To eliminate this
condition, explosion-proof drains and breathers should be
installed to automatically bleed off accumulated water.
Cable made specifically for harsh, salt-water environments
must be used in areas where high humidity or salt water
is a problem. In all cases, typical cable insulation
resistance should measure 100 megohms or more,
using a high voltage insulation tester (megohmmeter). If
cable resistance drops below 10 megohms, it should be
replaced immediately to avoid shorting.
IMPORTANT
Disconnect the detectors and controller before
applying a megohmmeter to the cable.
When using steel wire armored or mineral-insulated
copper-sheathed cables, select an approved gland with
a watertight compression stage and an overall gland
shroud for outdoor applications. A sealing washer must
be fitted between the gland and the conduit entry to
ensure IP66 rating.
NOTE
The wiring procedures in this manual are intended
to ensure proper functioning of the device under
normal conditions. However, because of the
many variations in wiring codes and regulations,
total compliance to these ordinances cannot be
guaranteed. Be certain that all wiring complies with
applicable regulations that relate to the installation
of electrical equipment in a hazardous area. If in
doubt, consult a qualied official before wiring the
system.

7.1 11 95-8242
DETECTOR POSITIONING AND DENSITY
The detector has a nominal 90° cone of vision. What this
means in practical terms can be understood by reference
to a typical installation. Consider an application such as
a loading rack with a ceiling height of 25 feet (7.5 meters),
and assume it is desired to have complete detector
coverage at floor level. If a detector is mounted 2 feet
(0.6 meter) from the ceiling and pointed straight down, the
distance from the detector to the designated level would
be 23 feet (7 meters). Because of its 90° cone of vision,
the detector would cover a circular area with a diameter
of 46 feet (14 meters) at the designated level. A simple
layout of the area to be covered will easily reveal the
number of detectors required to completely supervise the
designated area. In general, detectors should be placed
as close as practical to the probable hazard.
NOTE
Do not mount UV detectors close to the ceiling in
enclosed areas if dense smoke can be expected
to accumulate at the onset of a re. Mounting the
detector on side walls a few feet (or about 1 meter)
down from the ceiling will normally allow time for
the detectors to respond before they are affected
by smoke rising to the ceiling. It is also advisable
to shorten any time delay settings for applications
where smoke may accumulate during a re. If
dense smoke can be expected to accumulate prior
to the presence of ame (as in an electrical re), do
not use UV detectors alone.
MOUNTING THE DETECTOR
The following procedure should be used for mounting
and wiring the detectors.
1. Detectors should be located for the best unobstructed
view of the area to be protected. Detectors must
be accessible for cleaning the viewing window and
reflector rings. Care must be taken so that dirt or other
foreign material will not accumulate and obscure the
detector viewing window.  For outdoor applications,
the detectors should be pointed downward to prevent
the cone of vision from scanning the horizon, since the
detectors can be affected by long duration lightning
flashes or distant arc welding. When practical,
mount the detectors so that the UV test lamp is on
top, since dirt accumulation between the window and
the reflector ring can interfere with the Automatic oi
function.SeeFigure4formountingdimensions.
2. Disassemble the detector enclosure by turning the
housing cover counterclockwise. If the detector is
equipped with a cover locking device, loosen the
clamp and disengage the “catch” from the terminal
cap.  See Figure 9 for an illustration of the detector
assemblyandFigure10fortheoptionalcoverlocking
assembly.
NOTE
Power must not be applied to the system while
opening the detector housings, or while plugging in
or removing the sensor tube modules.
3. Install the A-, B-, C-, and D-leads to the connections
ontheterminalblock.SeeFigure11.Donotground
the shield to the detector housing.
TERMINAL BLOCK
INDEX PIN
O-RING
WINDOW AND HOUSING
Oi REFLECTIVE RING
UV SENSOR MODULE
TERMINAL CAP
A2078
Figure 9—C7050 Detector

7.1 12 95-8242
NOTE
Many wiring codes prohibit the connection of a
shield to the negative terminal of a power source
(terminal 2 of the controller). If such a connection
is permitted, the detectors can be wired using a 3
wire shielded cable. The shield is connected to the
“C” terminal of the detector in place of a separate
C-lead. (See Figure 23).
4. Remove the UV sensor tube module from its shipping
package. When handling the sensor tube module,
be careful not to touch the sensor tube, since oil from
the skin can attenuate UV radiation, reducing the
sensitivity of the tube.
IMPORTANT
Use only DE1888 sensor modules with the C7050
Detector. The jumper plug must not be installed
on the UV sensor module used with the R7404
Controller (see Figure 12). The jumper plug is
supplied for detectors that are used with other
controller models.
5. Using the index pin as a guide, install the sensor
module on the detector terminal block.
6. Re-assemble the detector housing. If the detectors
are equipped with cover locking devices, loosen the
clamp sufficiently so that the “catch” can be seated
in the blind hole provided on the terminal cap. (See
Figure10.)Theclampmustthenbefastenedsecurely
around the detector barrel by tightening with the
proper tool.
NOTE
If the wires from individual detectors are connected
to the R7404 Controller using a multiple conductor
cable with a single outer shield and without twisted
pairs, careful placement of the individual detector
leads is necessary to prevent “cross-talk” between
zones. The individual B-leads should be arranged
around the outside of the cable with a ground lead
between. The inner layer of conductors should be
the D-leads and the common A-lead should be in
the center.
When using multiconductor cable with twisted
pairs, only one leadwire of each twisted pair can
be connected to the B-terminal in the detector.
The other leadwire must be used as a shield by
connecting it to the C-terminal in the detector and
to ground terminal 2 on the R7404. When several
detectors are connected to one controller using
twisted pairs of leadwires, a junction box is required
to connect the many ground leads together so
that only one ground leadwire need be run to the
controller. (Keep this common ground leadwire as
short as possible.) Ground all unused leads at the
controller. For additional information refer to Service
Memo 75-1003, “Multiconductor Cable Wiring.
B0769
CATCH
BARREL
WINDOW CAP
TERMINAL CAP
BLIND HOLE
CATCH SCREW
STRAP
COVER
LOCKING
ASSEMBLY
Figure 10—Detector with Cover Locking Assembly
REMOVE JUMPER PLUG
A2079
Figure 12—Jumper Plug
QUICK CONNECT PLUG (4)
SIGNAL (B)
oiFUNCTION (D)
GROUND (C)
+290 VDC (A)
C0125 INDEX PIN
Figure 11—Detector Terminal Block

7.1 13 95-8242
CONTROLLER
The controller is furnished with a field wiring connector that
incorporates pressure type screw terminals for attaching
wires and two circuit board edge connectors for plugging
in the controller.
The controller must be located in a non-hazardous area.
The use of a mounting cage is recommended for mounting
the controller. The cage is designed to hold the field wiring
connectors for ease in making electrical connections and
installing, servicing, or replacing the modules. The Q4004
Mounting Cage is designed to hold up to 8 modules in a 19
inchinstrumentrack(SeeFigure5).Thismountingcage
can also house voltage converters or other equipment
thatisusedinconjunctionwiththeR7404aspartofthe
total detection system. Cages that hold fewer modules
are also available. Optional filler panels (part number
002188-001) are available for covering unused sections
of the mounting cage.
NOTE
TheR7404Controllercontainsseveralsemiconductor
devices that are susceptible to damage by
electrostatic discharge. An electrostatic charge
can build up on the skin and discharge when an
object is touched. Therefore, the controller should
be handled carefully, taking care not to touch the
terminals or electronic components. For more
information on proper handling of the controller,
refer to the Service Memo (form 75-1005)
Switch Setting Procedure
It is essential that the controller be properly
programmed before applying power to the system.
There are four rocker switch assemblies on the left side of
the controller. Each switch assembly has eight rockers,
which are opened or closed to select zone and detector
combinations, controller sensitivity, fire logic, output
latching,andtimedelay.Figure13illustratestheleftside
of the R7404 and contains a short explanation of rocker
switch usage.
SWITCH 3
FIRE LOGIC SETTING
OP = OPEN, CL = CLOSED, DC = DON'T CARE
A•B = A AND B
SENSITIVITY SELECTION
ROCKER 3-4 CLOSED = 64 CPS
ROCKER 3-3 CLOSED = 32 CPS
ROCKER 3-2 CLOSED = 16 CPS
ROCKER 3-1 CLOSED = 8 CPS
(ALL ROCKERS OPEN
OR ROCKER 3-1 CLOSED = 8 CPS)
THESE ROCKERS MAY BE USED
IN ANY COMBINATION FOR 8 CPS TO 120 CPS
3-8
CL
CL
CL
CL
OP
OP
OP
OP
3-7
DC
DC
DC
DC
3-6
DC
DC
OP
CL
ALL OPEN
1 CLOSED
2 CLOSED
3 CLOSED
3-5
OP
CL
DC
DC
A (1 OF ZONES 1 TO 4)
A (2 OF ZONES 1 TO 4)
B (1 OF ZONES 5 TO 8)
B (2 OF ZONES 5 TO 8)
A•B (1 OF 8 ZONES)
A•B (2 OF 8 ZONES)
A•B (3 OF 8 ZONES)
A•B (4 OF 8 ZONES)
FIRE LOGIC OUTPUTS
ROCKER POSITION
A0274
SWITCH ROCKER NUMBERS ARE DESIGNATED 1-1, 1-2, 1-3, ETC.
THE NUMBER PRECEDING THE DASH INDICATES THE SWITCH NUMBER.
THE NUMBER FOLLOWING THE DASH INDICATES THE ROCKER NUMBER
OF THE SWITCH INDICATED.
NOTE:
8
7
6
OPEN
8
7
6
OPEN
DOT INDICATES ROCKER DEPRESSED
ROCKER POSITIONS
CLOSED OPEN
DETECTOR SELECTION SWITCHES 1 AND 2
THESE TWO SWITCHES PROGRAM THE MICROPROCESSOR
FOR EACH DETECTOR CONNECTED
SWITCH 1
PLACE ROCKER IN OPEN POSITION
FOR EACH DETECTOR IDENTIFIED AS NO. 1
IN ZONES 1 THROUGH 8
SWITCH 2
PLACE ROCKER IN OPEN POSITION
FOR EACH DETECTOR IDENTIFIED AS NO. 2
IN ZONES 1 THROUGH 8
}
}
SWITCH 4
TIME DELAY
AND LATCHING/NON-LATCHING OUTPUTS
ROCKER 8 – NOT USED
ROCKER 7 – NOT USED
ROCKER 6 – 8 SECOND DELAY
ROCKER 5 – 4 SECOND DELAY
ROCKER 4 – 2 SECOND DELAY
ROCKER 3 – 1 SECOND DELAY
ROCKER 2 – .5 SECOND DELAY
(ALL SWITCHES OPEN, TIME DELAY = 0)
ROCKER 1 – LATCHING OUTPUTS
WHEN ROCKER IS OPEN
Figure 13—Rocker Switches

7.1 14 95-8242
CAUTION
Use care when setting the rocker switches on the
controller. An incorrectly set rocker switch can result
in an obvious controller malfunction, or in some
cases the controller can appear to be functioning
normally, but will not produce the desired output
in response to the input conditions. (Some of the
switches are not used and should be left in the
open position.)
The rocker switches must be set before power is applied
to the system. Do not plug the controller in or remove
it from the mounting rack while power is turned on.
1. Zone and Detector Selection — Switch Assemblies
1-1 to 1-8, and 2-1 to 2-8
Each zone can have either one or two detectors for
a maximum of 16 detectors in 8 zones connected
to one controller. Rockers 1-1 through 1-8 are used
to enable the detectors connected to position No.
1 of each zone. Rockers 2-1 through 2-8 enable
position No. 2 of each zone. The appropriate rocker
must be set to the “Open” position for each detector
connected. Care must be taken when setting these
rockers. If a rocker is set open, but no detector is
connected in the location, the controller will show a
“2” fault on the lower digital display and the detector
display will show either a “1” or “2”, depending on
which detector is not connected in the zone. The zone
display will show the incorrectly set zone. If a rocker is
set closed, but a detector is connected, the controller
performs normally, but that detector is eliminated from
the Automatic oitest sequence, and any faults that
may occur in its circuit would not be automatically
identified. This condition can be found only when
performing the manual oitest procedure.
 See Figure 14 for an example of selection switch
setting for a system using 12 detectors in 8 zones.
2. Controller Sensitivity — Rockers 3-1 to 3-4
Rockers 3-1 to 3-4 are used to program controller
sensitivity in 8 cps increments.
3-1 closed — 8 cps
3-2 closed — 16 cps
3-3 closed — 32 cps
3-4 closed — 64 cps
The values of the closed rockers are added together.
The rockers can be set in any combination to give the
sensitivity setting selected for the application, up to 120
cps.
NOTE
If no rockers are closed, or if only rocker 3-1 is
closed, the controller responds to an 8 cps signal
from the detector.
 RefertoFigure15foranexampleofa24cpssetting.
3. Fire Logic (Voting) — Rockers 3-5 to 3-8
Rockers 3-5 to 3-8 select the voting requirements,
whichcanbeFireLogicAandBcommon (8zones
voting)orFireLogicA(4zonesvoting)separatefrom
Fire Logic B (4 zones voting).  When separate, Fire
Logic A consists of zones 1 to 4, and Fire Logic B
consistsofzones5to8.SeeFigure16.
NOTE
When the outputs are set for non-latching operation,
the voting process will actuate the Fire Logic
output(s) only if the pre-selected number of voting
zones “see” re at the same time. When the outputs
are set for latching operation, the voting process
will actuate the Fire Logic output(s) when voting
criteria have been met, even if re is not being seen
by each voting zone at the same time.
Separate - Rocker 3-8 closed
 Rocker3-5programsFireLogicA(zones1to4)
— when open, votes one of four zones
— when closed, votes two of four zones.
 Rocker3-6programsFireLogicB(zones5to8)
— when open, votes one of four zones
— when closed, votes two of four zones
FireLogicAandBCommon—Rocker3-8open
3-5, 3-6, 3-7 open — votes one of eight zones
3-5 closed; 3-6 and 3-7 open — votes two of eight
zones
3-5 and 3-6 closed; 3-7 open — votes three of eight
zones
3-5, 3-6, 3-7 closed — votes four of eight zones
IntheexampleillustratedinFigure17,thesettingisfor3
of 8 zones voting.
8
7
6
5
4
3
2
1
8
7
6
5
4
3
2
1
OPEN OPEN
C7050 ZONE 8
C7050 ZONE 7
C7050
C7050 ZONE 6
C7050
C7050 ZONE 5
C7050 ZONE 4
C7050 ZONE 3
C7050 ZONE 2
C7050
C7050 ZONE 1
C7050
DETECTOR ZONES
SELECTION SWITCHES
DETECTOR 1
ZONES 1 – 8 SWITCH 1
DETECTOR 2
ZONES 1, 2, 6, 7 SWITCH 2
TOTAL = 8 ZONES, 12 DETECTORS A279
Figure 14—Detector and Zone Selection

7.1 15 95-8242
4. Output Latching/Non-latching — Rocker 4-1
closed — non-latching
open — latching
NOTE
The zone and re logic outputs will latch when
turned on if rocker 4-1 is set open. The outputs
are de-latched by placing the keylock switch in the
RESET position.
5. Time Delay — Rockers 4-2 to 4-6
The output signals can be delayed as follows:
4-2 closed — 0.5 second
4-3 closed — 1 second
4-4 closed — 2 seconds
4-5 closed — 4 seconds
4-6 closed — 8 seconds
The total time delay is the added value of all closed
rockers. Rockers can be closed in any combination
for a time delay from 0 to 15.5 seconds in half second
increments.Fornotimedelay,allrockersmustremain
open.
 Figure18showstheswitchsettingforatimedelayof
6 seconds.
System Layout
When the proper position for each of the rocker switches
has been determined, record this information carefully in
thespaceprovidedontheSystemLayoutChart(Figure
19). This chart is intended as an aid in system layout,
and also provides both a means of double checking
rocker switch positions before power is applied to the
controller and a record of rocker switch positions for
future reference.
Electrical Connections
All electrical connections are made to the field wiring
connectorthatisfurnishedwiththecontroller.Figure20
shows the terminal configuration for the controller.
8
7
6
5
4
3
2
OPEN
NOTE: THE VALUE OF ROCKERS SET IN THE CLOSED POSITION ARE ADDITIVE A0282


8 SECOND TIME DELAY
4 SECOND TIME DELAY
2 SECOND TIME DELAY
1 SECOND TIME DELAY
0.5 SECOND TIME DELAY
}NOT USED
ROCKER 5 CLOSED = 4 SECONDS
ROCKER 4 CLOSED = 2 SECONDS
TOTAL TIME DELAY = 6 SECONDS
Figure 18—Time Delay Setting




4
3
2
1
OPEN
3-1 CLOSED = 8 CPS
3-2 CLOSED = 16 CPS
TOTAL SENSITIVITY = 24 CPS
SWITCH 3
A0281
Figure 15—Controller Sensitivity Setting
NO
NO FIRE LOGIC
OUTPUT
ANY ONE OR
MORE ZONES
SEE FIRE
ONE ZONE
SELECTED?
B0288
ONE OF
FOUR
ZONES SELECTED
YES
ONE OF EIGHT
ZONES
SELECTED
FIRE
LOGIC
SELECTED
ZONE OUTPUT(S)
FIRE LOGIC
OUTPUT
A OR B
FIRE LOGIC
OUTPUT
A AND B
NO
NO FIRE LOGIC
OUTPUTS
ANY TWO OR
MORE ZONES
SEE FIRE
TWO ZONES
SELECTED?
TWO OF
FOUR
ZONES SELECTED
YES
TWO OF EIGHT
ZONES
SELECTED
ZONE OUTPUTS
FIRE LOGIC
OUTPUT
A OR B
FIRE LOGIC
OUTPUT
A AND B
NO
NO FIRE LOGIC
OUTPUTS
ANY THREE OR
MORE ZONES
SEE FIRE
THREE ZONES
SELECTED?
YES
ZONE OUTPUTS
FIRE LOGIC
OUTPUT
A AND B
ANY FOUR OR
MORE ZONES
SEE FIRE
FOUR ZONES
SELECTED?
YES
ZONE OUTPUTS
FIRE LOGIC
OUTPUT
A AND B
Figure 16—Fire Logic Flow Chart
8
7
6
5
3 OF 8 ZONES VOTING
SWITCH 3
A0280
OPEN
Figure 17—Fire Logic Setting

7.1 16 95-8242
Up to 16 detectors in 8 separate zones can be connected
to the controller. Terminals A, B, and D on the detectors
must connect to the appropriate A, B, and D terminals
at the controller. Connect terminal C on the detector as
well as the shields to power supply negative (terminal
2) at the controller. Do not connect the shields to the
detectors. Insulate the shields to prevent shorting to the
device housing or to any other conductor. Connect a
non-polarized 0.47 microfarad 250 vdc capacitor from
terminal 64 (chassis ground) to terminal 2. This places
the controller chassis and the power supply negative at
the same ac potential, minimizing the induction of noise
into the system through the detector wiring.
NOTE
External equipment that can generate transients
when switching (such as relays) must have a
transient suppression device (diode) connected
across the coil at the time of installation. This will
safeguard the output transistors of the controller
against possible damage. Figure 21 illustrates
an inductive load with a diode used for transient
suppression.
SWITCH 1 DETECTOR 1
SWITCH 4 TIME DELAY
SWITCH 4
LATCHING/NON-LATCHING
ROCKER OPEN CLOSED
ROCKER OPEN CLOSED
ROCKER OPEN CLOSED
8
7
6
5
4
3
2
1
1
8
7
6 (8 SEC)
5 (4 SEC)
4 (2 SEC)
3 (1 SEC)
2 (.5 SEC)
8
7
6
5
4
3
2
1
8
7
6
5
4
3
2
1
8
7
6
5
4
3
2
1
8
7
6
5
4
3
2
1
OPEN SWITCH FOR EACH
DETECTOR CONNECTED
NOT USED
OPEN OPEN OPEN OPEN
A0278
SWITCH 2 DETECTOR 2
ROCKER OPEN CLOSED
8
7
6
5
4
3
2
1
SWITCH 3 FIRE LOGIC
ROCKER OPEN CLOSED
8
7
6
5
SWITCH 3 SENSITIVITY
ROCKER OPEN CLOSED
4
3
2
1
THE POSITION OF ROCKER 
NO. 8 DIVIDES THE SYSTEM 
INTO TWO GROUPS OF FOUR
OR ONE GROUP OF EIGHT
SENSITIVITY COUNT
SELECTED WHEN ROCKER
IS IN "CLOSED" POSITION
{
{
NOT USED
SWITCHES CLOSED
ARE ADDITIVE
LATCHING – OPEN
NON-LATCHING – CLOSED
R7404 SIDE VIEW
Figure 19—System Layout Chart
100K
R7484
OPEN COLLECTOR OUTPUT
1N4004
TYPICAL
+60 VDC MAXIMUM
C1289
Figure 21—Transient Suppression Device
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
+
– 
(A) +290 VDC
B - INPUT 1
B - INPUT 2
B - INPUT 3
B - INPUT 4
B - INPUT 5
B - INPUT 6
B - INPUT 7
B - INPUT 8
D1-1 oiDRIVER
D1-2 oiDRIVER
D1-3 oiDRIVER
D1-4 oiDRIVER
D1-5 oiDRIVER
D1-6 oiDRIVER
D1-7 oiDRIVER
D1-8 oiDRIVER
D2-1 oiDRIVER
D2-2 oiDRIVER
D2-3 oiDRIVER
D2-4 oiDRIVER
D2-5 oiDRIVER
D2-6 oiDRIVER
D2-7 oiDRIVER
D2-8 oiDRIVER
DMA OUT AVAILABLE
DMA OUT
DMA IN
DATA STROBE
DMA IN AVAILABLE
ZONE OUTPUT 1
ZONE OUTPUT 2
ZONE OUTPUT 3
ZONE OUTPUT 4
ZONE OUTPUT 5
ZONE OUTPUT 6
ZONE OUTPUT 7
ZONE OUTPUT 8
FIRE LOGIC “A”
FIRE LOGIC “B”
ALARM OUTPUT
EXTERNAL RESET/INHIBIT
OUTPUTS INHIBITED
FAULT OUTPUT
EXTERNAL ACCEPT
STATUS & DET. OUTPUT S1
STATUS & DET. OUTPUT S2
STATUS & DET. OUTPUT S3
STATUS & DET. OUTPUT S4
STATUS & DET. OUTPUT S5
STATUS & DET. OUTPUT S6
STATUS & DET. OUTPUT S7
STATUS & DET. OUTPUT S8
DATA BUS 0
DATA BUS 1
DATA BUS 2
DATA BUS 3
DATA BUS 4
DATA BUS 5
DATA BUS 6
DATA BUS 7
CHASSIS (EARTH) GND
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
J2
R7404
J1
10 TO 38 VDC
}
SOLID STATE OUTPUTS MUST BE TRANSIENT PROTECTED, SEE TEXT FOR DETAILS
*
D0284
*
Figure 20—R7404 Terminal Conguration (Standard Model)

7.1 17 95-8242
TYPICAL SYSTEM APPLICATIONS
The following typical applications are examples only.
SeeFigures22,23and24.Forassistanceinadaptinga
systemtoyourindividualrequirements,contacttheField
Support Group at Detector Electronics.
The system illustrated in Figure 22 furnishes solid state
outputsignalsfromzones1to5,FireLogicAandB,and
the Alarm output. External Inhibit and External Accept
are shown connected for use in locations remote from
the controller. Other connections are not used in this
configuration.
External Inhibit/Reset (terminal 44) is a means of remotely
inhibiting the output circuits and resetting the controller.
External Accept (terminal 47) is a means of remotely
turning off the alarm output. These functions can be
performed by a computer interface, external switches, or
any interface that drives the input to less than 0.5 vdc.
Outputs Inhibited (terminal 45) is an output that is driven
low when the controller is in the Outputs Inhibited mode
(keylock switch in TEST or RESET position or External
Inhibit/Reset switch closed).
The system illustrated in Figure 23 furnishes solid state
output signals from zones 1 to 3, Fire Logic A and B,
and the Alarm output. External Inhibit and External
Accept are shown connected for use in locations remote
from the controller. Other connections are not used in
this configuration. In this illustration the detectors are
connected using a 3 wire shielded cable, with the shield
functioning as the C-lead.
NOTE
Wiring codes in many areas do not permit the
detectors to be wired using the method shown in
Figure 23. Therefore, this should be considered an
alternate method for use only where codes allow.
The system illustrated in Figure 24 furnishes solid state
outputsignalsfromzones1through8,FireLogicAand
B, and the Alarm output. External Accept and External
Inhibit are shown connected for use in locations remote
from the controller. Other connections are not used in this
configuration.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
+
– 
(A) +290 VDC
B - INPUT 1
B - INPUT 2
B - INPUT 3
B - INPUT 4
B - INPUT 5
B - INPUT 6
B - INPUT 7
B - INPUT 8
D1-1 oiDRIVER
D1-2 oiDRIVER
D1-3 oiDRIVER
D1-4 oiDRIVER
D1-5 oiDRIVER
D1-6 oiDRIVER
D1-7 oiDRIVER
D1-8 oiDRIVER
D2-1 oiDRIVER
D2-2 oiDRIVER
D2-3 oiDRIVER
D2-4 oiDRIVER
D2-5 oiDRIVER
D2-6 oiDRIVER
D2-7 oiDRIVER
D2-8 oiDRIVER
DMA OUT AVAILABLE
DMA OUT
DMA IN
DATA STROBE
DMA IN AVAILABLE
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
ZONE OUTPUT 1
ZONE OUTPUT 2
ZONE OUTPUT 3
ZONE OUTPUT 4
ZONE OUTPUT 5
ZONE OUTPUT 6
ZONE OUTPUT 7
ZONE OUTPUT 8
FIRE LOGIC “A”
FIRE LOGIC “B”
ALARM OUTPUT
EXTERNAL RESET/INHIBIT
OUTPUTS INHIBITED
FAULT OUTPUT
EXTERNAL ACCEPT
STATUS & DET. OUTPUT S1
STATUS & DET. OUTPUT S2
STATUS & DET. OUTPUT S3
STATUS & DET. OUTPUT S4
STATUS & DET. OUTPUT S5
STATUS & DET. OUTPUT S6
STATUS & DET. OUTPUT S7
STATUS & DET. OUTPUT S8
DATA BUS 0
DATA BUS 1
DATA BUS 2
DATA BUS 3
DATA BUS 4
DATA BUS 5
DATA BUS 6
DATA BUS 7
CHASSIS (EARTH) GND
A
B
C
D
C7050
ZONE 1
A
B
C
D
C7050
ZONE 2
A
B
C
D
C7050
ZONE 3
A
B
C
D
C7050
ZONE 4
A
B
C
D
C7050
ZONE 5
FIRE ALARM CONTROL CABINET
A
B
C
D
A
B
C
D
J1-3
J1-7
J1-2
J1-15
A
B
C
D
J1-3
J1-5
J1-2
J1-13
A
B
C
D
J1-3
J1-6
J1-2
J1-14
A
B
C
D
J1-3
J1-8
J1-2
J1-16
D0285
0.47 uf, 250 VDC
NON-POLARIZED
J2
R7404J1
10 TO 38 VDC
}

Figure 22—Typical System - Five Detectors in Five Zones

7.1 18 95-8242
Status and detector output terminals 48 to 55 provide
binary output representations of the front panel digital
displays for zone, detector, and system status. Tables
3 and 4 list the identification codes and the logic states
ofthe“Fault”and“OutputsInhibited”bitsforthevarious
status conditions.
Under “normal” (no fault) conditions, the Fault output is
energized (logic 1).
The Data Bus terminals (56 to 63) and the DMA (direct
memory access) and Data Strobe terminals (28 to 32)
provide external access to the microprocessor, which
permits inter-controller communication.  For further
information,contacttheFieldSupportGroupatDetector
Electronics. (This feature is only available on R7404
models with Remote Surveillance, Nuclear Surveillance
and STAR Logic.)
STARTUP PROCEDURE
CAUTION
Placing the controller in the Test mode inhibits
its outputs, rendering the system incapable of
actuating any extinguishing or alarm circuits that
are connected to it. For maximum safety, however,
secure output loads (remove power from any devices
that would normally be actuated by the system)
before manually testing the system. Remember to
place this same equipment back into service when
the test is complete.
1. After setting the selection switches and making all
electrical connections, plug the controller into the
connector.
2. Turn on power and perform Checkout Procedure.
3. If the controller appears to be operating normally,
remove mechanical blocking devices and restore
power to the extinguishing loads.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
+
– 
(A) +290 VDC
B - INPUT 1
B - INPUT 2
B - INPUT 3
B - INPUT 4
B - INPUT 5
B - INPUT 6
B - INPUT 7
B - INPUT 8
D1-1 oiDRIVER
D1-2 oiDRIVER
D1-3 oiDRIVER
D1-4 oiDRIVER
D1-5 oiDRIVER
D1-6 oiDRIVER
D1-7 oiDRIVER
D1-8 oiDRIVER
D2-1 oiDRIVER
D2-2 oiDRIVER
D2-3 oiDRIVER
D2-4 oiDRIVER
D2-5 oiDRIVER
D2-6 oiDRIVER
D2-7 oiDRIVER
D2-8 oiDRIVER
DMA OUT AVAILABLE
DMA OUT
DMA IN
DATA STROBE
DMA IN AVAILABLE
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
ZONE OUTPUT 1
ZONE OUTPUT 2
ZONE OUTPUT 3
ZONE OUTPUT 4
ZONE OUTPUT 5
ZONE OUTPUT 6
ZONE OUTPUT 7
ZONE OUTPUT 8
FIRE LOGIC “A”
FIRE LOGIC “B”
ALARM OUTPUT
EXTERNAL RESET/INHIBIT
OUTPUTS INHIBITED
FAULT OUTPUT
EXTERNAL ACCEPT
STATUS & DET. OUTPUT S1
STATUS & DET. OUTPUT S2
STATUS & DET. OUTPUT S3
STATUS & DET. OUTPUT S4
STATUS & DET. OUTPUT S5
STATUS & DET. OUTPUT S6
STATUS & DET. OUTPUT S7
STATUS & DET. OUTPUT S8
DATA BUS 0
DATA BUS 1
DATA BUS 2
DATA BUS 3
DATA BUS 4
DATA BUS 5
DATA BUS 6
DATA BUS 7
CHASSIS (EARTH) GND
A
B
C
D
C7050
ZONE 1
A
B
C
D
C7050
ZONE 2
A
B
C
D
C7050
ZONE 3
A
B
C
D
C7050
A
B
C
D
C7050
FIRE ALARM CONTROL CABINET
A
B
C
D
A
B
C
D
J1-3
J1-5
J1-2
J1-21
A
B
C
D
J1-3
J1-4
J1-2
J1-20
A
B
C
D
J1-3
J1-5
J1-2
J1-13
A
B
C
D
J1-3
J1-6
J1-2
J1-22
D0286
J2
R7404J1
10 TO 38 VDC
}
A
B
C
D
C7050
A
B
C
D
J1-3
J1-6
J1-2
J1-14
0.47 uf, 250 VDC
NON-POLARIZED
Figure 23—Typical System - Six Detectors in Three Zones