Motorola PTP 250 User Manual page 71

PTP 250 User Guide
Basic requirements
The following basic protection requirements must be implemented:
x
The ODU must be in 'Zone B' (see
x
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.
x
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.
x
The drop cable must be grounded at the building entry point.
x
The drop cable must not be laid alongside a lightning air terminal.
x
All grounding cables must be a minimum size of 10 mm
16 mm
Grounding cable requirements
When routing, fastening and connecting grounding cables, the following requirements
must be implemented:
x
Grounding conductors must be run as short, straight, and smoothly as possible,
with the fewest possible number of bends and curves.
x
Grounding cables must not be installed with drip loops.
x
All bends must have a minimum radius of 203 mm (8 in) and a minimum angle of
90°
follow the contour or run parallel to the supporting structure.
x
All bends, curves and connections must be routed towards the grounding
electrode system, ground rod, or ground bar.
x
Grounding conductors must be securely fastened.
x
Braided grounding conductors must not be used.
x
Approved bonding techniques must be used for the connection of dissimilar
metals.
phn-2182_002v000
May 2011
2
csa (6AWG), or 25 mm
(Figure 2-2). A diagonal run is preferable to a bend, even though it does not
Grounding and lightning protection
Lightning protection zones
2
csa (4AWG).
on page 2-11).
2
csa (8AWG), preferably
2-13