Det-Tronics U7602B-P Unitized UV Flame Detector/Controller - Manual (Page 7)

period, the Fire relay is energized and the current out-
put signal rises to a level indicating that the U7602 is
seeing a fire. If the detector module is equipped with
an LED, it will illuminate. The Fire relay time delay (the
time between when a flame is detected and the Fire
relay is energized) is factory-set at 5 seconds, but is
field adjustable from 0.025 to 30 seconds so that it
can be set to fit each particular installation. The Fire
relay is non-latching (unless otherwise specified) and
resets when UV is no longer being sensed. If latching
Fire relay is specified, power must be removed from
the detector for more than 0.5 second to reset.
The Fault relay is normally energized (contacts
closed), indicating a no fault condition. If a fault
occurs in the U7602 or power is lost, the Fault relay is
de-energized and its contacts open. The Fault relay
is non-latching so if the fault is no longer present, the
relay will energize (contacts close). During oi faults
the Fault relay energizes and de-energizes approxi-
mately once every 2 seconds. The Fault relay con-
tacts close approximately 4 seconds after power is
applied to the detector provided a fault is not present.
NOTE
When a manually activated oi test is performed,
the Fault relay will open momentarily after the
test switch is released and the Fire relay resets
(no problems detected), which will result in a nui-
sance fault annunciation if the external monitor-
ing equipment does not have a time delay.
The current signal output line can be wired to an
external meter for remote monitoring of fire/fault con-
ditions in the U7602. Table 2 shows the conditions
that various current signal output levels represent for
both standard and optional 4 to 20 ma output models.
ENCLOSURE
The U7602 enclosure is explosion-proof and suitable
for use in hazardous/classified areas both indoors
and outdoors. The U7602 is a dust-tight and water-
tight unit that is designed to meet most national and
international standards. It is available in anodized
aluminum and 316 stainless steel. The aluminum
housing is epoxy coated, making it suitable for use in
high saline atmospheres, such as offshore platforms.
Conduit entries are available in 1/2 inch NPT, 3/4 inch
NPT, 20 mm, 25 mm and Pg16.
SPECIFICATIONS
SPECTRAL SENSITIVITY RANGE—
Det-Tronics UV detectors respond to UV radiation
over a wavelength of 1850 to 2450 angstroms. The
detectors are insensitive to direct or reflected sunlight
and to normal artificial lighting.
4
UV DETECTOR
IR DETECTOR
UV TEST LAMP
OPTICAL SHIELD
VIEWING WINDOW
SNAP-IN oi RING
IR TEST LAMP (2)
IR SENSING ELEMENT
SNAP-IN oi RING
OPTICAL FILTER
VIEWING WINDOW
UV SENSOR
B1048
Figure 2—Detector with oi
Figure 3—TB3 on Standard Controller Module
Figure 4—TB3 on Optional Form C and 4 to 20 ma
Output Controller Modules