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Tech Tips;Surge Protection/11886
Index1.Netw orking Systems //Video Products//Video Security Systems
Tech Tips
PR22511V2-133059.eps
Protecting Your Security Equipment Against High-voltage Surges
ITW LINX
A Lightning Rod of Security
A Lightning Rod of SecurityA Lightning Rod of Security
A Lightning Rod of Security
The proliferation of externally mounted IP-based network cameras is increasing the risk of fire, damage or serious injury and death caused by a
high-voltage surge event such as an incidental lightning strike or a power line cross. Because the dense charge of positive electrons residing on objects
protruding from the earth attracts the negative charge from a lightning strike, outside network cameras on rooftops and light poles become a focal point
for the high-voltage discharge, which can easily exceed 5,000 volts. Instead of drawing the charge to the earth, these cameras act as virtual lightning
rods, drawing the high-voltage current to the data center or telecom room through the copper cabling infrastructure.
Without proper protection, a 100-volt shock lasting a few nanoseconds can seriously damage or destroy valuable networking equipment. Unlike telephone
lines, current standards and codes governing building entrance protection are ambiguous in their requirements for IP-based outdoor network cameras.
This lack of installation standardization continues to expose sensitive networking equipment within the building structure to damage from a surge of
voltage or current.
The Evolution of Networking Configurations
The Evolution of Networking ConfigurationsThe Evolution of Networking Configurations
The Evolution of Networking Configurations
This threat comes from the evolution of the video surveillance network from a standalone configuration to an integrated system utilizing a single cabling
network. In traditional analog video surveillance systems, a single coaxial cable runs from a camera directly back to the video headend. In a networked
video surveillance system, all of the IP-based cameras are attached to the same network, which runs back to a telecom room or data center where
mission-critical equipment is kept. Although an overvoltage can damage both analog and IP cameras and the equipment to which they are connected, IP
video cameras can also cause damage to critical Ethernet network components and infrastructure that resides on the same network.
Best Practices for Safeguarding Network Equipment
Best Practices for Safeguarding Network EquipmentBest Practices for Safeguarding Network Equipment
Best Practices for Safeguarding Network Equipment
To prevent damaging the networking equipment in this scenario, we recommend following Article 800 of the National Electrical Code, which specifies the
installation of primary protection for all conductive communications paths entering or leaving a building, but no more than 50 feet past the building
entrance. The article recommends using a UL 497 Listed primary protector. Using a solid-state modules rather than a traditional gas-tube module is
recommended because of its much faster clamping time during a high-voltage surge event and its increased longevity. Even after multiple surge hits,
solid-state modules don't typically need replacing. Lastly, the use of a UL 497A secondary protector will mitigate further risk of equipment damage from
voltage surges that were not eliminated using a UL 497 primary protector.
Power Protection and UL, What Does It Mean?
Power Protection and UL, What Does It Mean?Power Protection and UL, What Does It Mean?
Power Protection and UL, What Does It Mean?
Different UL Listings mean different things for good reasons, safety. The highest UL Listing for surge protection products is UL 497, which can be easily
confused with UL 497A and UL 497B. Here is a look at the difference:
UL 497 or Primary Protection:
UL 497 or Primary Protection: UL 497 or Primary Protection:
UL 497 or Primary Protection: The Primary Protector is used at building entrances and is capable of withstanding the highest level of
over-voltage surges, lightning. These devices are required by NEC Article 800 to protect buildings and humans.
UL 497 A or Secondary Protection:
UL 497 A or Secondary Protection:UL 497 A or Secondary Protection:
UL 497 A or Secondary Protection: The Secondary Protector is located between the building entrance/primary protector and the equipment
intended to be protected. These protectors are intended to protect buildings, humans and sensitive electronic equipment.
UL 498 B or Isolated Loop Protection:
UL 498 B or Isolated Loop Protection:UL 498 B or Isolated Loop Protection:
UL 498 B or Isolated Loop Protection: Isolated Loop Protectors are designed to handle overvoltage events which are introduced within a
building. The protected "loop" must not be exposed to the outside world. These protectors are not designed to protect against
lightning-type surges but are for low-voltage protection only.
S03Dat2.fm Page 33 Tuesday, December 11, 2012 10:00 PM