220.127.116.11.2.4 Lightning/EMP Protection. Electrical surge arresters should be used on all power and signal
cables at the shelter points-of-entry to provide protection from lightning and EMP induced currents on
inter-shelter cabling. Lightning protection should also be provided in accordance with Section 1.3.
18.104.22.168.2.5 Collocated Shelters Greater than 8 Meters Apart. Collocated shelters located greater than
8 meters (26.5 feet apart refers to equipment systems consisting of multiple shelters (which has interfacing
shelters located as much as 250 feet apart) as opposed to an equipment system in which all elements are housed
in a single shelter. These shelters may therefore also be considered as stand-alone shelters. Where deployment
requires shelters to be located more than 8 meters (26.5 feet) apart, grounding should be accomplished in
accordance with Figure l-100 and as follows:
22.214.171.124.2.5.1 Ground Resistance Difference of Less Than 150 Ohms. If ground resistance measurements of all
shelters differ by less than 150 ohms, ground each shelter as a stand-alone shelter (reference 126.96.36.199).
188.8.131.52.2.5.2 Ground Resistance Difference of Greater Than 150 Ohms. If differences in ground resistance
measurements are 150 ohms or more, take corrective action (reference 184.108.40.206) to reduce resistance, and
ground each shelter as a stand-alone shelter (reference 220.127.116.11).
Figure l-100. Connecting Ground Subsystems for Collocated Shelters Greater than 20 Feet Apart