Det-Tronics xWatch Explosion-Proof Camera with X-Series Flame Detectors - Manual (Page 5)

2.3 95-8603 5
INSTALLATION
CAUTION
Installation and wiring of the flame detection
system should be performed only by qualified
personnel. Refer to the flame detector instruction
manual for general installation instructions.
VIDEO CABLE CONSIDERATIONS
Proper video cable will ensure that the best quality video
is displayed on a remote monitor. Because composite
video frequencies span the range of 25 Hz to 6 MHz,
most cables will display transmission line characteristics.
Ensure that the same cable type (impedance) is used
throughout the entire length. For example, do not mix
twisted pair cable and coaxial cable without using a
balun for matching. In addition, the monitor end must
be properly terminated. Failure to properly implement
the video cabling system may result in smearing (loss of
detail) and/or loss of color and/or loss of picture sync.
The xWatch employs a balanced differential video
driver designed to drive twisted pair cable of 100 ohm
impedance. The best video performance in terms of
distance, video quality, and cost is attained using a 22
AWG to 16 AWG unshielded twisted pair cable of 100
ohm impedance. The wiring can be Category 2 or better,
stranded or solid.
The monitor end must terminate the video cable with 100
ohms. Most monitors have a built in termination resistor.
If the monitor uses 75 ohms instead of 100, a balun or
other matching network must be used.
Coax such as RG-59 or RG-6 may be used, but be sure to
use proper matching and termination devices. There are
manufacturers who support driving many types of cable
systems using active transceivers that compensate for
cable losses.
Galvanic isolation of the video may also be necessary
to avoid horizontal bars caused by line frequency
interference. This may be accomplished using isolating
active transceiving systems or passive video isolation
transformers/baluns. Specify a baseband video isolation
system with a frequency response of at least 25 Hz to 6
MHz. Small cable TV transformers will generally not work
as their frequency response is not low enough.
WIRING PROCEDURE
CAUTION
Power must not be applied to the device while the
housing is open.
ATTENTION
Observe precautions for handling electrostatic
sensitive devices.
1. With the housing cover removed, wire the flame
detector as shown in the detector manual.
2. Connect the external wiring for the xWatch to the
appropriate screw connectors on the terminal block.
See Figures 4 and 5.
IMPORTANT
Do not test any wiring connected to the xWatch
with a meg-ohmmeter. Disconnect wiring at
the camera before checking system wiring for
continuity.
3. Complete installation and commissioning of the
system as described in the detector instruction
manual.
9
8
7
6
5
4
3
2
1
19
18
17
16
15
14
13
12
11
mA + mA –
mA + REF mA – REF
COM FIRE COM FIRE
N.O. FIRE N.O. FIRE
N.C. FIRE N.C. FIRE
COM FAULT COM FAULT
N.O. FAULT N.O. FAULT
24 VDC + 24 VDC +
24 VDC – 24 VDC – 24 VDC –
29
28
27
26
25
24
23
22
21
VIDEO +
VIDEO –
COM AUX
N.O. AUX
N.C. AUX
RS-485 A
RS-485 B
MAN Oi
B2386
Figure 4—Terminal Wiring Block for Standard Flame Detectors
A2387
COM 2 B
24 VDC –
VIDEO +
VIDEO –
24 VDC +
POWER SHIELD
COM SHIELD
COM 2 A
COM 1 B
24 VDC –
24 VDC +
POWER SHIELD
COM SHIELD
COM 1 A
14
13
15
16
17
18
11
12
2
1
3
4
5
6
Figure 5—Terminal Wiring Block for EQP Models