Essential Boat Electrics E-Book

Oliver Ballam

• Herausgeber: Fernhurst Books Limited
• Kategorie: Fachliteratur
• Sprache: Englisch

Veröffentlichungsjahr: 2021

Beschreibung

Electricity is vital on board most boats: to keep their systems running and to provide the crew with the services they expect. Much of it will be professionally fitted and many yachtsmen will have little knowledge about the finer detail of electric circuits. But, given the importance of electrical power, some understanding of it is likely to be useful: either to use when required away from the marina or to repair and upgrade your systems. This book is written to provide that understanding and to allow you to undertake electrical jobs on board yourself, properly and safely. It removes the mystique of boat electrics and gives you the confidence to tackle the jobs when you need to. Included are the minimum formulae and theory required, focussing more on the practical – using simple language and clear illustrations. There are tutorials, from using a multimeter and wiring a circuit, to troubleshooting electrical faults, all using easy-to-follow photo sequences. The book also looks at tasks such as choosing solar panels and batteries and connecting navigational instruments. The book is a great manual for a yachtsman needing to keep the power flowing. It has been thoroughly modernised and updated for this new edition by boating electric wizard Oliver Ballam.

Leseprobe

THE AUTHORS

PAT MANLEY & OLIVER BALLAM

PAT MANLEY

Pat Manley was a long-time contributor to the magazine Practical Boat Owner and regularly featured in their Ask the Experts pages. He also wrote a number of successful books for Fernhurst Books: Simple Boat Maintenance, Diesels Afloat, Practical Navigation for the Modern Boat Owner, Electrics Companion, Diesel Companion and Radar Companion.

His books, articles and the numerous RYA courses he ran inspired thousands of sailors with practical advice that meant that they could understand and repair their boats.

Pat passed away in September 2016.

This left Fernhurst Books with the problem of finding someone to update Pat’s work when the time came and nowhere was this going to be more necessary in the ever-changing world of boat electrics.

We are delighted that Oliver Ballam has updated this work.

OLIVER BALLAM

Oliver Ballam was brought up in Suffolk on the banks of the River Deben and the river was his natural playground on the various family boats. His passion for boating and studying electronics at school have combined to create his career.

After school he taught sailing in the Med, which also involved considerable boat maintenance with minimal tools or equipment. On his return to the UK, he helped a friend build and race a Mini Transat yacht. Amongst other things this involved installing the electrical system which led to other electrical work around the boatyard, which led to the formation of Seapower Marine Electronics. Seapower is now one of the East Coast’s leading marine electronics and electrical companies, based at Suffolk Yacht Harbour in Levington and providing sales installation and repair services to yacht owners and crew.

INTRODUCTION

Pat had a friend whose boat’s appetite for amps was minimal. He had a small solar panel, but where he kept his boat, the sun set at 10am, even in the summer. He had a small wind charger, but the mooring was so sheltered it rarely turned. He had an engine, but it had no generator. He had a battery, but he took it home to charge. Peter had a cabin lamp, navigation lights and basic instruments and he wanted no more. These days Peter is a rarity.

Whether power or sail, today’s boats need quite a lot of electricity, be it low voltage DC or mains voltage AC. To the majority of yachtsmen, electricity is a bit of a closed book, and we hope that it’s those people who will find this book useful.

Essential Boat Electrics is not intended to be very theoretical, quite the reverse. Where a formula might be useful, we’ll give it. Where a bit of theory is likely to help understanding, we’ll give that too. In the main, it’s a matter of simple words and pictures, as we find that when talking to other yachtsmen, that’s what they want.

To many sailors, electrics is a black art. Essential Boat Electrics is intended to help remove the fog of mysticism from the subject. To the purist, we may use terms that they disagree with. Someone said about Electrics Companion that you can’t ‘consume’ electric power! The correspondent may have been technically correct, but it’s an expression understood by all, so that’s what we use.

However, a word of warning – if you don’t understand AC power, leave AC circuits strictly alone.

Each chapter covers a specific range of topics. This is a bit of a problem when setting their order, as we often had to write about a topic not yet covered, no matter in which order they were arranged. So, where necessary, we tell you where to look for that bit of information.

We cannot stress too much that you should make a wiring diagram of any modifications you make. You won’t find the professional doing that, but if you’re going to keep track of things, please do take the time to make one. It doesn’t have to be pretty, all it needs to do is to tell the story.

It’s also very easy to procrastinate and say, ‘Oh! I’ll tidy it all up later.’ It works OK and so you put off the evil day that you make it all neat and secure. As soon as you know it works, finish it off properly there and then, or it won’t get done.

That’s the preaching finished, so get on and use Essential Boat Electrics to help you do all those electrical jobs that you wished you had the knowledge to do.

CONTENTS

1. The Basics

2. The Tools

3. Multimeters

4. Batteries

5. Electrical Supply

6. Switches & Relays

7. Connections

8. Wiring

9. Circuits

10. Electric Motors & Alternators

11. Navigation Instruments

12. Anodes

13. Soldering

14. Power Consumption

Appendices

Useful Tables

Useful Formulae

Acknowledgements

CHAPTER 2

THE TOOLS

If you are going to carry out any basic electrical repairs, installation or troubleshooting, a suitable electrical tool kit is needed. For convenience, it’s probably a good idea to keep this separate from your normal tool kit.

Installing instruments may also require some additional tools, such as hole-saws to cut mounting holes in instrument panels and an electric drill and drill bits.

METERS & CHECKERS

Multimeter

When troubleshooting, a multimeter is almost essential. They can measure DC and AC voltage, current, resistance and more depending on the model.

A multimeter

A probe multimeter is less versatile (with fewer functions) but more compact and has the advantage that as one probe is the meter itself, it can be used in awkward places.

A probe-type multimeter

Polarity Checker

If you haven’t got an onboard polarity checker installed, this is essential every time you connect to shore power. It is also essential if you are going to fit any mains sockets. Many devices are not protected from overload or potentially dangerous faults if the polarity is incorrect (see page 41).

A polarity checker

Clamp Ammeter

Clips onto a cable to measure the current flowing through the wire. It’s not especially accurate but can measure high currents and you don’t need to make any connections. It’s especially useful for checking the output of the alternator. You just need to clip it to the alternator’s output cable.

Clamp ammeter

Non-Contact Voltage Checker

Useful for checking if AC voltage is present in a wire or appliance without exposing live parts. Just hold the tip near the wire to be checked and it will glow and / or beep depending on the model. Also useful to double check a circuit is safely isolated before working on it.

Non-contact voltage checker

BASIC TOOLS

Side Cutters

The best tool for cutting wire. With care, they can also be used for stripping wire, but you have to hold the handles so that they will just cut the insulation and not the wire.

Side cutters

Wire Strippers

The only really satisfactory way to strip insulation from wire. There are various types. With some you must use the correct size ‘notch’ or you will sever some of the wire’s strands, increasing its electrical resistance and weakening the wire. Others will automatically strip just the insulation and not the conductor.

Above: Automatic wire strippers

Notch wire strippers

Long-Nosed Pliers

Ordinary pliers are just too blunt ended for electrical use. The long, tapered long-nosed pliers are indispensable for many electrical jobs.

Long-nosed pliers

Hobby Knife

Used for many odd cutting jobs. You will need this for cutting insulation on heavier cable where it isn’t cost effective to purchase a bigger wire stripper. However, do be very careful not to cut through inner insulation where there’s a sheath over multi-strand insulated wire.

Hobby knife

Screwdrivers

Many connectors have small screws, as do junction boxes and the components themselves. A range of suitably-sized screwdrivers − blade and cross-head − is essential. Include a set of small instrument screwdrivers.

A set of screwdrivers

CRIMPING

Various Crimp Terminals

Crimping is the most versatile method of making electrical joints. The better terminals have two stages to grip both the insulation and the conductor. This improves the vibration and pull-out resistance of the terminal; it also makes a better connection because the metal of the terminal is held in contact more firmly with the metal of the conductor.

Crimp with two stage grip (above)

Crimp with only single grip

Crimping Tool

The only proper way to make crimped joints − the cheap crimping pliers are not good enough for making proper joints. A ratchet crimping tool is the type to use. There are different makes of crimp terminals, so it’s best to buy the crimper and the terminals from the same source if you can.

A crimping tool

Heavy Duty Crimping

If you have to crimp up some heavy-duty terminals and don’t have the luxury of an expensive heavy-duty crimper, then you can buy a much cheaper device which can have the pressure applied either by a hammer or in a vice.

A heavy-duty crimping tool

If you can take the wire to a vice, insert the wire into the terminal and then squeeze the crimper in the vice until the tool’s end-stops touch. Make sure you hold the wire firmly in place in the terminal as you close the vice.

If you have to use a hammer, rest the crimper on a firm surface. This is probably a two-person job: one to hold the wire and terminal and the other to do the hammering. You will need good teamwork!

SOLDERING

Mains Soldering Iron

If mains power is available, a 25-watt mains iron is an asset. If you have heavier work to do, a 100-watt iron is necessary. See Chapter 13: Soldering for technique.

A mains soldering iron

12-Volt Soldering Iron

For use on board, when no mains power is available, a 12-volt iron will do all that a mains one will do. However, it will take 2 amps at 12 volts, so you won’t want to leave it on for long periods. These days, gas irons are more often used due to their superior power and versatility.

A 12-volt soldering iron

Gas Soldering Iron

For jobs where electricity isn’t readily available, a gas soldering iron is a big asset. A professional one is a much better tool than its cheaper rivals, which, in my experience, suffer from rapid failure of their catalytic element. Although these ‘irons’ can have a naked flame if required, for soldering, the gas burns without a flame on a catalytic element, just as in a catalytic heater. This element heats the soldering tip. A rope-cutting heated tip and a hot air tip are often supplied as well.

They will generally have a hot exhaust, so be careful where and how it is put down so that it doesn’t burn the surface.