General Protection Requirements - Motorola PTP 250 User Manual

PTP 250 User Guide

General protection requirements

To adequately protect a PTP 250 installation, both ground bonding and transient voltage
surge suppression are required.
Basic requirements
The following basic protection requirements must be implemented:
•
The ODU must be in 'Zone B' (see
•
A lightning protection unit (LPU) must be installed within 600 mm (24 in) of the point
at which the drop cable enters the building or equipment room.
•
The drop cable must be bonded to the supporting structure in order to prevent
lightning creating a potential between the structure and cable, which could cause
arcing, resulting in fire risk and damage to equipment.
•
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
mm 2 csa (6AWG), or 25 mm
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°
(Figure 2-2). 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.
phn-2182_003v004 (Oct 2011)
Lightning protection zones
2 csa (4AWG).
UNDER DEVELOPMENT
Grounding and lightning protection
on page 2-16).
2
csa (8AWG), preferably 16
2-17