5
Lightning & Surge Protection
The product adopts multi-level anti-lightning and anti-surge technology integrated with gas discharge tube, power resistor and TVS tube. The
powerful lightning and surge protection barrier effectively avoids product damage caused by various pulse signals with power below 4kV,
including instantaneous lightning, surge and static. However, for complicated outdoor environment, refer to instruction below for lightning
and surge protection:
The product features with dedicated earth wire, which must be firmly grounded. As for surveillance sites beyond the effective protection
scope, it’s necessary to erect independent lightening rods to protect the security devices. It’s recommended to separate the lightning rod from
the mounting pole, placing the rod on an independent pole, as shown in the figure below. If the product has to be installed on the same pole or
pedestal for lightning rod, there should be strict insulation between the video cable BNC terminal, power cable, control cable and the standing
pole of the lightning rod.
For suburb and rural areas, it’s recommended to adopt direct burial for the transmission cables. Overhead wiring is prohibited, because it’s
more likely to encounter lightning strike. Use shielded cables or thread the cables through metal tubes for burial, thus to ensure the electric
connection to the metal tube. In case it’s difficult to thread the cable through the tube all the way, it’s acceptable to use tube-threaded cables
only at both ends of the transmission line, yet the length in burial should be no less than 15 meters. The cable sheath and the tube should be
connected to the lightning -proof grounding device.
Additional high-power lightning-proof equipment and lightning rods should be installed for strong thunderstorm or high induced voltage
areas (such as high-voltage substation).
The lightning protection and grounding for outdoor devices and wires should be designed in line with the actual protection requirement,
national standards and industrial standards.
The system should perform equipotential grounding by streaming, shielding, clamping and earthing. The grounding device must meet
anti-interference and electric safety requirements. There should be no short-circuiting or hybrid junction between the device and the strong
grid. Make sure there’s a reliable grounding system, with grounding resistance below 4
Ω
(below 10
Ω
for high soil resistivity regions). The
cross-sectional area of the earthing conductor should be no less than 25mm².
Lightning rod
Front device for
surveillance system
Separated layout for the lightning
rod and the standing pole
LPZO
B
LPZO
A
Mounting pole
for front device
30°
30°
