Det-Tronics C7050 A, C, G, P UV Flame Detector - Manual (Page 7)

tors to fulfill voting requirements, and represents the best
balance between reliability of fire detection and freedom
from false actuation due to individual detector malfunc-
tion.
Fault Identification
The automatic fault identification feature of the R7404
operates much the same as on other Det-Tronics equip-
ment, 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” sec-
tion for a detailed description.
SPECIFICATIONS
SPECTRAL SENSITIVITY RANGE—
The detector 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. 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 +167°F (–40°C to +75°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.
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 sen-
sitivity 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 inter-
nal 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 dam-
age. 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 mm
2 or 0.0005 in 2 . Its
Table 1—System Status Codes
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.
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