Grounding and lightning protection
PTP 450 Configuration and User
pmp-0815 (August 2015)
4-25
Zone B: In this zone, direct EMD (lightning) effects are still possible, but mounting in
this zone significantly reduces the possibility of a direct strike. Mount equipment in
this zone.
Never mount equipment in Zone A. Mounting in Zone A may put equipment,
structures and life at risk.
General protection requirements
To adequately protect a PTP 450 installation, both ground bonding and transient voltage
surge suppression are required.
Basic requirements
The following basic protection requirements must be implemented:
The equipment must be in ‘Zone B’ (see
on page
The radio (BHM/BMS) must be grounded to the supporting structure.
A surge suppression unit (600SS) must be installed close to the radio.
The distance between the ratio and 600SS must be kept to a minimum.
The drop cable length between the radio and 600SS must be less than 600 mm.
A surge suppression unit (600SS) must be installed within 600 mm (24 in) of the point
at which the power cable enters the building or equipment room.
The drop cable must be grounded at the building entry point.
The drop cable must not be laid alongside a lightning air terminal.
All grounding cables must be a minimum size of 10 mm
2
csa (8AWG), preferably 16
mm
2
csa (6AWG), or 25 mm
2
csa (4AWG).
Grounding cable requirements
When routing, fastening and connecting grounding cables, the following requirements
must be implemented:
Grounding conductors must be run as short, straight, and smoothly as possible, with
the fewest possible number of bends and curves.
Grounding cables must not be installed with drip loops.
All bends must have a minimum radius of 203 mm (8 in) and a minimum angle of 90°
(
). A diagonal run is preferable to a bend, even though it does not follow the
contour or run parallel to the supporting structure.
All bends, curves and connections must be routed towards the grounding electrode
system, ground rod, or ground bar.
Grounding conductors must be securely fastened.
Braided grounding conductors must not be used.
Approved bonding techniques must be used for the connection of dissimilar metals.