I will shortly be setting up my first MT based AP using RB500 and CM9.

Yesterday, we had a lightning storm and one of my smartBridges AP locked up and needed a power cycle.

It got my wondering what sort of lightning protection I could/should implement for the MT AP. It will be using an omni antenna fed with about 3m of LMR400 mounted on a two story building. Power will be by passive PoE. Is there any advantage in using a metal case for the AP? Should the power supply negative be connected to ground and/or the AP case?

Any advice appreciated.

Stick a lightening arrestor on the antenna run and make sure its grounded to a good earth.

A metal chassis that is grounded for the AP would probably make for slightly better emp protection.