The physical construction of the shielded cable dictates to a degree the
grounding system, but regardless of the cable type you want protection
at both the upper and lower ends of the cables. So-called armored CAT5/6
cable with corrugated copper shield is normally fitted with ground kits
similar to what is used on Heliax coax plus it's connected to surge
arrestors; while cable with the more common foil/drain wire construction
is often terminated with *shielded* modular plugs and plugged into surge
protectors incorporating shielded jacks. The protector will have a
ground lug which is connected to the upper ground bar if one exists, or
via a down lead to the ground level ground system.
Check out the L-Comm website for a variety of surge protection devices.
This page shows some combo surge protector/power injector gizmos:
On 8/24/2011 9:19 PM, Michael Fox - N6MEF wrote:
> I'm going to be installing a couple of WiFi antennas on a couple of towers
> in the near future. The radio sits on the back of the antenna so the only
> wire coming off the tower is an Ethernet cable (with 24VDC Power over
> Ethernet to power the radio).
> In the past, I have used PolyPhaser devices at the building entrance
> bulkhead for my RF cables and rotator cables. I am aware of but have not
> yet used grounding kits for bonding the coax or hardline shield to the tower
> leg. (I didn't use them because I didn't have a tower at the time).
> Looking at the PolyPhaser website (www.protectiongroup.com) I see they have
> PoE Surge Protectors. They appear to be inline devices that, perhaps, would
> be strapped to a tower leg, but I'm not sure. There is no user manual
> posted on the site. I wonder if this would be sufficient or if I would also
> need to somehow ground the shield of the Ethernet cable (typically a very
> light weight foil - don't know if that's even possible).
> Is anyone familiar with grounding/bonding practices for outdoor PoE Ethernet
> cables going to WiFi antennas on towers? If so, I'd be appreciative of
> pointers to how-to's, or other helpful info you might have.
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