Ground the roof. I have a hay barn where there are some AC mains just 14ft away and it induces about 80VAC to the roof. We first thought there was a ac break someplace, but we shut down ALL the power to the property. Unless the bread is in the weather head to the meter base/breaker panel (all above ground) then we have a induced voltage from the mains to the roof. When this site was first installed I was completely below roof line at one end of the barn (40ft wide, 35ft tall, mounted at the 15ft level) as it sits right up on a knob. Kept losing ethernet ports even with grounding and suppressors. Figured it had to do with the wood and poor grounding (via AC, back to the shop). Drove a ground rod and tied to the power enclosure, radio enclosure and directly to the antenna mounts. At the same time I moved up the pole to the roof line (20ft) and got a shock that nearly killed me. Not for the current, but because it was to my EAR. I jumped about 5ft from the building and landed about half way down the fiber glass ladder. All other times being on site a fully metal ladder was used (13ft) and was far short of the metal roof. I was stunned to have been shocked. After grounding the roof I have not lost a single ethernet port since even with out grounding not counting after having the ground line cut (farmer nicked the pole when loading hay, did not notice the ground was cut).
On Mon, Oct 4, 2010 at 8:49 PM, Greg Ihnen <[email protected]> wrote: > Lightning took out my RB-750 today. This is the second one I lost to > lightning. Are the RB-450's any better made or more resistant to lightning? > > I have protection, shielded ethernet cable and grounding but the gear is > mounted up on a metal roof that is not grounded and when there's a nearby > strike the roof is getting an induced charge and it's knocking out the gear. > Besides losing an RB-750 I lost the ethernet port of a UBNT PS2 and it's > power supply. > > Tomorrow the gear comes off the roof. It's going on a grounded pole. I have > other gear on top of a grounded Quonset hut and there's no problems. > > Greg > > > -------------------------------------------------------------------------------- > WISPA Wants You! Join today! > http://signup.wispa.org/ > -------------------------------------------------------------------------------- > > WISPA Wireless List: [email protected] > > Subscribe/Unsubscribe: > http://lists.wispa.org/mailman/listinfo/wireless > > Archives: http://lists.wispa.org/pipermail/wireless/ > -------------------------------------------------------------------------------- WISPA Wants You! Join today! http://signup.wispa.org/ -------------------------------------------------------------------------------- WISPA Wireless List: [email protected] Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
