CHAPTER
12 Grounding Systems
L
et’s delve a little deeper into the vital but often ignored subject of grounding sys-
tems. Depending upon a boat’s equipment list, a grounding system will serve as
many as four primary needs:1 Protect individuals from electrical shock (see Chapter 10).
2 Minimize corrosion (see Chapter 11).
3 Provide lightning protection.
4 Minimize RFI and/or provide a radio antenna counterpoise.In this chapter we’ll look at lightning protection and the basic radio frequency ground
plate. In Chapter 16 we’ll look at what happens when we tie in an SSB radio counterpoise,
which is basically a slightly more elaborate grounding system that serves as half of the
radio’s antenna system.Lightning Protection
Lightning is both powerful and mysterious. We have been observing it for centuries, devot-
ing much study and research to learning what it is, how to control it, and how to minimize
its powerful effects. That said, and in spite of all our efforts, the best lightning protection sys-
tem (LPS) really can’t guarantee personal safety or protection from equipment damage. I tell
my seminar attendees that lightning is truly an act of God, and you can only do so much to
insure yourself against a strike; after that, you can just hope—or pray—for the best!
Most of what we know about lightning protection has been figured out by carefully
observing the damage after a strike and drawing conclusions from these observations. The
stuff is just too hard to catch and experiment with!
So what have we learned from these observations as they relate to boat installations? It
can be narrowed down to a few key points, which are compiled in ABYC Technical Infor-
mation Report TE-4 (formerly Standard E-4), Lightning Protection. Below I’ve adapted
some of the basic guidelines provided in that report for installing an LPS or modifying an
existing grounding system:- Lightning is an electrical discharge, and moves due to a difference in electrical poten-
tial. Like all electricity, it’s trying to get to Mother Earth, or ground. - Once “captured” by an electrical conductor, the conductor should provide as straight
and direct a route as possible to ground, and have the ability to handle the high volt-
age and current present.
Copyright © 2007 by Edwin R. Sherman. Click here for terms of use.