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TECHNICAL TIP >>
Protect your CCTV system from lightning and
electrical surges.
WARNING: Your CCTV security system is
vulnerable! Whether your equipment is located indoors or outdoors,
the continuous operation of your CCTV security system is vulnerable to
unpredictable disruption via electrical surges and lightning strikes. A
camera system is more likely to be damaged by lightning strikes and surges
than other building systems due to a number of reasons.
One factor is the broad reach of a camera network. A CCTV system consists
of a wire structure with multiple ground paths, with cameras mounted all
over a building. This means that if one node in the system becomes
electrically elevated, current will flow from the other system nodes. This
network of cables is connected through the central CCTV control equipment
and current flow will be felt directly by the “heart” of the system.
Another factor is the sensitivity of the central processing equipment used
in CCTV systems which is mostly microchip based and not designed to handle
surge currents. The DVR (digital video recorder) is the most critical of
these units and it also represents the largest single cost in your system.
It looks for one volt peak to peak on its input, meaning it can be easily
over loaded.
There are three main ways lightning enters homes and buildings - via a
direct strike, through wires or pipes that extend outside of the
structure, and through the ground. Self contained CCTV systems often cross
paths or interconnect with wiring, plumbing or structural metal that
extends outside of the building - yet another factor that makes the system
vulnerable to lightning strikes and surges, regardless of whether the
equipment is located indoors or out doors.
So how do you protect a CCTV system from lightning and electrical
surges?
Via single point grounding. The most important thing is to prevent current
flow through the electronics of the system. Isolating the whole system
from any electrical grounding is not practical but it is possible to block
surge currents from entering the components of the system. EQL
Teleconnect’s E10510 Surge Suppressor will do this by providing a safe
path to ground for over voltage signals. Properly installed, the unit
provides a single ground point for the unit it is protecting, eg. a
camera. The protected equipment no longer sees any signal larger than the
clamping voltage and with the single ground point, there is no current
flow through the unit, thus protecting other components in the system, eg.
other cameras and your DVR.
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