Article by Pat Schrawder
THE IMPORTANCE OF GOOD GROUNDING
Obviously, the equipment on your boat will operate to its best if it is installed properly and you understand how to use it. For all your equipment to work at its optimum requires that it have sufficient input power and that it be as free as possible from “noise” or interference from other sources. This is best accomplished by using the proper gauge wire for the power and by providing adequate ground. Why is this important? It is a matter of safety and performance.
Adequate ground reduces noise and interference in some items and is absolutely essential for successful performance of your single sideband radio. Most manufacturers recommend running a separate ground wire to their unit. Many of them provide a ground bolt or wing nut on the back of the unit for just that purpose. It usually isn’t a difficult thing to do and I would highly recommend you take the time and effort to do it. The way equipment ground connections are designed, they make it somewhat more cumbersome to remove your equipment from the boat and, for that reason, people often ignore them. For example, it is more often than not, a bolt with a wing nut onto which you put a wire with a ring tongue terminal. A good solution is to make that wire connection to the equipment a short one of six inches or so and on the other end, place a “quick disconnect” terminal end that connects to another long wire which is permanently linked to your ship’s ground system.
A good ground for your boat consists of a complete system, not just one or two critically run wires. Ideally, it starts with a ground plate. Ground plates are made of thousands of tiny copper beads, fused together into a rectangular block that is about one half-inch thick and comes in several sizes. Because the beads are round, they provide a great deal of copper surface in a small space. The larger the block, the greater the resulting ground equivalent. In any case, a ground plate provides ground that is electrically equal to a huge copper plate. They have a hole drilled in each end so that the ground plate can be secured with copper bolts which run through the hull to the outside in order to make contact with the water. The ground plate is then attached to the bolt at one end with a copper strap, braid and/or wire which is then run to a central place on the boat that is accessible. A single large bolt run through a bulkhead to which the ground wire is attached makes a good, easy source for a ground hookup. The important thing is that your ground is completely bonded to a single point. In other words, you do not want several separate grounds, each doing its own thing. You need all of your grounding run to one central location and then connected to a single wire that runs straight to the ground (water).
If you do not have a ground plate, you can use an existing through-hull fitting. Do not use a transducer through-hull fitting, however, as that can only lead to another problem like electrolysis. If you are having problems with through-hull fittings corroding off or taking on a strange color, you already have evidence of electrolysis and need to address it soon before it causes damage that can be very costly.
During a storm event, a good bonding system can save you from very expensive damage to your electronics. Lightning is looking for a connection to ground. It will instinctively seek the shortest path with the least resistance. If your vessel’s ground system is to be effective, you need to provide just that, a short, easy path to ground for the lightning bolt to follow that doesn’t compromise your electronic equipment.. If you don’t, lightning will “wander” around your boat, looking for a way out to ground. This can cause complete melt-downs of equipment and mini “explosions” of electrical components in your equipment that can rarely be fixed.
There are a number of products out there that help you achieve the desired results. There are the basic grounding components such as copper strap and/or wire and ground plates. There are also other products such as noise filters to eliminate alternator interference, other line filters, power management systems, isolators, etc.
One of the manufacturers with the most comprehensive line of products for this purpose is New Mar. They can be found on the internet at www.newmarpower.com. It is well worth a look just to see the wide range of available items. Installation of these items and correct bonding of your vessel can be time consuming but the results are worth it. Unless you are very comfortable in your own knowledge of how to design and install correct grounding, etc. on your boat, this is a job that might be better left to the professionals
Pat and her husband, Larry are owners of L&L Marine Electronics on Golf Course Road in West Ocean City, MD.
