External cameras need lightning protection.

We’ve had a camera installed on a pole mounted to one of our buildings hit by lightning and this has highlighted the fact none of our external cameras are protected. What would you recommend to reduce potential damage?

A: Buildings are different to remote pole mounts, which would need to be grounded independently, with camera grounded to grounded poles. A remote pole would typically be fitted with a low resistance path to ground via a lightning rod, fat cable and buried metal matrix.

In your case, which action you for cameras attached to building depends on whether the building is fitted with an external lightning protection system. If it is and the camera is not within the protected volume, then you need an air termination rod installed at the pole with cabling installed inside the metal pole.

If in-pole cabling is impossible, then cable needs to be run in a metal conduit that’s electrically connected to the pole. Whether or not you need surge protectors in the cable run depends on cable length. None if the run is only a couple of metres, some if cabling is longer.

There should also be lightening equipotential bonding at the entry point for cabling as it goes from the junction box on the pole into the building. If buildings have no external lightning protection, it’s possible the lightning risk is very low and can be mitigated by installing surge protectors between the junction box and camera.

Alternatively, your buildings may need to be professionally grounded.

#securityelectronicsandnetworks.com