The complete guide to expanding, upgrading, surveying and troubleshooting your boat’s AC and DC electrical system. CLICK HERE TO ENTER 888-658-BOat (2628) E-mail: [email protected] www.diy-boat.com ©2007 JM Publishing contents Systems Subscribe to DIY Boat Owner Design a Trouble-Free Electrical System 4 Preparing a Wiring Schematic 12 Index of DIY articles Power Consumption Worksheet 16 DC System Upgrades 17 Circuit Protection Devices 25 Help Fuses & Circuit Breakers 26 Fine Tuning DC Systems 30 Terms of Use Switches: Selection, Installation, Usage 33 Sample Switch Installations 36 Electrical Panel Selection & Installation 37 Disclaimer Upgrading a ‘70s Cruiser 42 AC Power: Components & Troubleshooting 46 Quit Hands-on Wiring AC Wiring Tips 54 Wiring Tools & Techniques 55 Crimping 101 58 Wiring Basics 59 Boat Wire List 60 Wire Standards 61 Wire Color Codes 62 Engine Wiring Color Codes 63 Wire Identification 64 Formula for Sizing Conductors 65 Conductor Sizing and Voltage 66 Conductor Ratings 67 Batteries Ratings, Performance & Efficiency 68 Selection & Sizing for House Loads 71 Selection, Installation, Maintenance 74 Battery Construction 78 Calculating Battery Requirements 79 (continues on next page) © DIY boat owner 2001 1-888-658-2628 © DIY contents (continued from previous page) Subscribe to DIY Boat Owner Reducing Electrical Demands 80 Easy-to-Make Battery Cables 83 Index of DIY articles 1995-2006 Batteries and Charging FAQ 84 Generating Power with Fuel Cells 87 Using Batteries to Produce AC Power 90 Help Charging Issues Terms of Use Solar, Wind and Water Power: Selection & Installation 94 Solar Panel Mounting Solutions 97 Disclaimer Charging Problems & Solutions 101 Inverter: Selection & Installation 103 Quit Gen-sets: Selection, Installation and Options 108 Battery Combiners & Isolators 112 Charge Controls for Charging Sources 115 High-Output Alternators 118 Upgrading an Alternator or Regulator 121 Troubleshooting Using a Multimeter 125 Testing a Boat’s DC Bonding System 127 Diagnostic Troubleshooting 130 AC System Troubleshooting 132 Troubleshooting Electrical Circuits 136 Troubleshooting Engine Electrical Systems 137 Breaking the Ground Circuit 140 Design a Trouble-Free ELECTRICAL SYSTEM Are you contemplating a major overhaul of your boat's Contents electrical system? Here's how to design an efficient trouble- free DC system and the proper techniques for installing electrical cables and circuits. Next By Kevin Jeffrey Sample Circuits circuit is a path that, if followed DC marine electrical circuits fall into two Previous completely, leads back to the starting categories — main circuits and branch or Aplace. Here we are concerned with marine subsidiary circuits. Main circuits originate electrical circuits that provide a reliable path from the batteries and provide current directly for direct current (DC). While there are definite to large appliance loads or to distribution rules to follow when wiring a new boat or points housing multiple branch circuits. While rewiring an existing one, the DC portion the methods of routing and controlling these of the electrical system can be set up in a circuits may vary, the wiring techniques for the variety of ways. With some creative thinking, best safety and efficiency remain the same. proper circuit components, and good wiring Shown in Figures 1 and 2 are three techniques, you can take the best advantage sample schematics depicting main and branch of battery-supplied electricity on board. DC circuits commonly found on boats. Keep in In DC circuits an electrical potential, or mind that components in a DC system can be voltage, drives the electrical current. Charging arranged in a variety of ways. sources create the necessary voltage to Codes for Conductors drive current into the batteries and, in turn, Wire conductors carry the current from the the batteries serve as a voltage source for voltage source to the loads. Other circuit operating all DC loads on board, including components to consider include connectors to inverters that, in turn, provide AC power. join conductors to electrical equipment or two A boat has both charging circuits and load or more wires together, distribution posts or circuits, yet all DC circuits must include busbars to conveniently join groups of positive the batteries. Individual batteries can be or negative wires, manual or automatic switches to control current flow, diodes to connected in a variety of ways to give you the prevent reverse current flow, and meters and system voltage and total battery capacity you monitors to help make electricity visible. require for house loads and engine starting Wire conductors provide the supply and (see Figures 1 and 2 for sample schematics return path from the voltage source to the and refer to pages 68, 72 and page 73 for various electrical loads. DC wiring is selected setting up batteries). for the type of job it must do, and is sized A DC system has a positive and according to how much current it's expected negative side to each circuit. The positive to safely carry and the allowable voltage drop side originates at the positive terminal of over its length of run. Conductors from 8 AWG the voltage source and goes to the positive (American Wire Gauge) to /0 AWG, usually referred to as cable, is used for positive and distribution point (if provided), then on to negative conductors where high current is individual loads. The negative side of the expected, such as battery banks, large high- circuit provides a return path back to the output alternators, starter motors, and large voltage source. The flow of electricity is inverters and chargers. Marine cable should determined by the electrical resistance of the meet the same standards as other conductors loads. For example, engine starters, freezers on board. and large inverters have relatively little Wire and cable conductors are insulated 888-658-BOat (2628) electrical resistance compared to lights and for safety and should be installed to make E-mail: [email protected] navigation instruments and, therefore, allow certain electricity stays in its intended path. If the electrical load is bypassed due to an www.diy-boat.com much more current to flow. (continued on page 6) ©DIY Boat Owner 2007 E-mail: [email protected] E-mail: 888-658- www.diy-boat.com ©DIY Boat Owner 2007 Owner Boat ©DIY Previous Next Contents BO at (2628) 1 6 3 2 5 System 22 Monitor 10 Main DC Negative Busbar Shunt 9 11 Main DC 1 Distribution 7 4 Panel 6 Volt 8 Running Lights 12 21 Instruments 6 Volt 14 Anchor Cabin Lights Winch Battery Voltage 1 Battery Terminal Boots VHF Parallel Regulator 2 400 amp Fuse Block Switch 3 Battery Switch On/Off 4 Cable Clamps 5 Posi-Lock Butt Connector Other House Loads Bilge 6 Split Loom Alternator 7 150 amp Common Busbar Pump 8 250 amp MEGA Fuse Starter Inverter 9 Ring Terminal with Adhesive- 12 Volt 15 Lined Heat-Shrink Tubing 16 10 Crimp-on Heat-shrink Ring 13 Terminal Battery 11 Butt Connector Charger 12 Disconnect 18 13 Water Block Adhesive 14 Pressure Connector 20 15 Circuit Breaker Panel 17 16 100 amp MEGA Fuse 17 Spiral Wrap 3 TYPICAL WIRING INSTALLATION RY 18 Bilge Pump Wire D 19 Oil-resistant Wire Inboard engine with single alternator, separate starting and 20 Power Post E HEN E I 19 house battery banks with automatic battery parallel switch, DC R A 21 Battery Cable Lugs electrical panel, separate bilge pump circuit and system monitor. 22 100 amp Common Busbar ANNE-M 2 Voltmeter 72” max Panel for unswitched loads such as + bilge pump Fuse 1 Contents 2 Next Battery Switch Fuse + Charge 7” - 40” rule Previous control Solar panel Outboard Distribution engine panel alternator 3-12V Main batteries System monitor distribution wired in panel parallel Shunt Main DC negative + busbar Anchor Sub winch panel 12V On/Off battery isolation switch To loads 12V + Inverter 12V Voltage Refrigerator regulator Battery parallel Bilge pumps Alt. 1 switch + Solar 1 Panel 12V Alt. 2 RY Starter 1 D Battery E HEN E 2 I 12V charger R Starter 2 A Engine starting ANNE-M SAMPLE BOAT SCHEMATICS (Top) (Bottom): Dual inboard engines with Single engine with alternator, two alternators, two starting and one house batteries with manual battery switch, battery bank with automatic parallel simple DC electrical panel, separate switch, multiple renewable charging bilge pump circuit, voltmeter (battery sources, DC electrical panel, separate condition meter) and solar panel. dual bilge pump circuits, system monitor, inverter, anchor winch and refrigeration. accidental "short" circuit, resulting high as the individual components and connections. current can cause serious damage and Selecting the proper conductor type and size is possibly a fire unless proper current a good place to start. Even though high-quality 888-658-BOat (2628) protection devices — fuses (Figure 1, #8) conductors made to AWG standards are more E-mail: [email protected] and circuit breakers — for each circuit are in expensive for a given size, they can actually www.diy-boat.com place. save you money over the long term. AWG The integrity of a DC circuit is only as good wires are up to 12% larger than the same ©DIY Boat Owner 2007 6 size SAE wire used for "surface vehicles," so runs require larger wire size. Conductors used in many applications a smaller gauge AWG for electronic equipment, navigation lights or wire can stay within the voltage drop limits other circuits where voltage drop should be recommended by American Boat & Yacht kept to a minimum shall be sized for a voltage Council (ABYC) and other marine standards drop not to exceed 3% (Table B on page 7). (Tables B and C on page 8). Conductors used for general lighting and other Wire conductors in a marine installation circuits where voltage drop is not critical may face harsh conditions, and must adhere to the be sized for a voltage drop of 10% (Table C Contents following criteria: on page 8).