Det-Tronics R7495D UV/IR Flame Detection System User Manual

Page 15

a. Connect the B-lead shields to the chassis

ground connection (terminal 5) of the con-
troller.

b. Be certain that the shield is NOT connected

to the detector at terminal “C” (circuit ground)
or any other points.

c. Connect the C-leads of the detectors to termi-

nal 2 (circuit ground) of the controller.

d. Connect a non-polarized 0.47 microfarad 250

vdc capacitor from terminal 5 to terminal 2.
This places the earth ground and the circuit
ground at the same ac potential, minimizing
induction of noise into the system through the
detector cable.

Check to make sure that all wiring is correct. If con-
duit is used, pour the conduit seals and allow them
to dry.

6. If the UV and/or IR sensor modules are already

installed in the detector housing, proceed to step
12. If the sensors are not installed, remove the
applicable sensor housings from the junction box
cover (see Figure 12). If the detectors are
equipped with a cover locking device (see Figure
15), loosen the clamp and disengage the “catch”
from the blind hole. The tool required is a 5/32-inch
hexagonal (Allen) wrench.

If the UV sensor module is already installed, pro-
ceed to step 9. If the UV module is not installed,
remove the UV sensor module from its shipping
package.

Determine the proper orientation for the UV module
by lining up the long index pin on the terminal block
with the hole in the printed circuit board of the mod-
ule. See Figure 12. Firmly press the module into
place on the terminal block, taking care not to touch
the glass envelope of the sensor module, since fin-
gerprints can absorb UV radiation and reduce the
sensitivity of the sensor.

IMPORTANT

If the UV sensor module is supplied with a jumper
plug “J” as shown in Figure 16, remove the jumper
plug from the detector tube module and discard it.
Jumper plug “J” is supplied for installations in
which the tube module is used with other detector
models.

NOTE

The C7052J contains semiconductor devices that
are susceptible to damage by electrostatic dis-
charge. An electrostatic charge can build up on
the skin and discharge when an object is touched.
Therefore, use caution when handling the detector,
taking care not to touch the terminals or electronic
components. For more information on proper han-
dling, refer to Service Memo form 75-1005 at the
front of this manual.

If the IR sensor is already installed, proceed to step
12. If the IR sensor is not installed, remove the IR
module from its shipping package (avoid touching
the IR sensing element at the top of the module).
Two IR sensor designs exist: 1) the DE5500 is elec-
trically connected via a wire harness on the junction
box that must be threaded through the sensor mod-
ule to a connector at the top of the module (see
Figure 17), 2) the DE3895 plugs directly onto a termi-
nal block in the base of the IR housing via connec-
tors on the bottom of the IR sensor module (see
Figure 12).

95-8331

24 VDC

POWER

SUPPLY

–

DETECTOR

NO. 1

C7052J

DETECTOR

NO. 2

C7052J

REMOTE

RESET

CHASSIS (EARTH) GROUND

CHASSIS GROUND

CKT GND

0.47

B1088

Figure 14—Detector Connection

BLIND HOLE

COVER

LOCKING

ASSEMBLY

CATCH

CLAMP

SCREW

STRAP

BARREL

LENS CAP

A1078

Figure 15—Cover Locking Assembly (Optional)