E-9 DIRECT CURRENT (DC) ELECTRICAL SYSTEMS ON BOATS
Based on ABYC's assessment of the existing technology, and the problems
associated with achieving the goals of this standard, ABYC recommends
compliance with this standard for all boats, associated equipment, and
systems manufactured after July 31, 1999.
The United States Coast Guard has promulgated mandatory requirements for
electrical systems in Title 33, CFR 183 Subpart I, Section 183. Refer to
the CFR for complete, current federal requirements.
These standards and recommended practices apply to direct current (DC)
electrical systems on boats that operate at potentials of 50 volts or
EXCEPTION: Any wire that is part of an outboard engine assembly and does
not extend inside the boat.
REQUIREMENTS - IN GENERAL
E-9.5.1 Two-Wire System - All direct current electrical distribution
systems shall be of the two-wire type. See Figures 1A and 1B, and
Figures 2A and 2B.
EXCEPTION: Engine mounted equipment.
E-9.5.2 DC Grounding Systems and Bonding - A metallic hull, or the
bonding and DC grounding systems, shall not be used as a return
conductor. See Figures 1A and 1B, and Figures 2A and 2B, and E-9.21, DC
Grounding and Bonding.
E-9.5.3 Grounded Systems - If one side of a two-wire direct current
system is connected to ground, it shall be the negative side and
polarized as defined in E-9.4.
E-9.5.4 Multiple Engine Installation - If a boat has more than one
engine with a grounded cranking motor, which includes auxiliary
generator engine(s), the engines shall be connected to each other by a
common conductor that can carry the cranking motor current of each of
the grounded cranking motor circuits. Outboard engines shall be
connected at the battery negative terminals.
E-9.5.5 Crossover (Parallel) Cranking Motor Circuits - In multiple
inboard engine installations, which includes auxiliary generator(s) with
cross-over (parallel) cranking motor systems, the engines shall be
connected together with a cable large enough to carry the cranking motor
current. This cable and its terminations shall be in addition to, and
independent of, any other electrical connections to the engines
including those required in E-9.5.4.
EXCEPTIONS: 1. Installations using ungrounded DC electrical systems.
2. Outboard engines.
E-9.5.6 If a paralleling switch is installed, it shall be capable of
carrying the largest cranking motor current.
NOTE: A paralleling switch may be either of the maintained contact or
momentary contact type.
E-9.5.7 DC System Negative Connections
E-184.108.40.206 If an alternating current (AC) system is installed, the main
AC system grounding bus shall be connected to
E-220.127.116.11.1 the engine negative terminal or the DC main negative bus on
grounded DC systems, or
E-18.104.22.168.2 the boat's DC grounding bus in installations using
ungrounded DC electrical systems. See ABYC E-8, AC Electrical Systems on
E-22.214.171.124 The negative terminal of the battery, and the negative side of
the DC system, shall be connected to the engine negative terminal or its
bus. On boats with outboard motors, the load return lines shall be
connected to the battery negative terminal or its bus, unless specific
provision is made by the outboard motor manufacturer for connection to
the engine negative terminal.
E-126.96.36.199 If an accessory negative bus with provision for additional
circuits is used for the connection of accessories, the ampacity of this
bus, and the conductor connected to the engine negative terminal or the
DC main negative bus, shall be at least equal to the ampacity of the
feeder(s) to the panelboard(s) supplying the connected accessories. See
Figures 1A and 1B, and Figures 2A and 2B.
E-188.8.131.52 If the negative side of the DC system is to be connected to
ground, the connection shall be made only from the engine negative
terminal, or its bus, to the DC grounding bus. This connection shall be
used only as a means of maintaining the negative side of the circuit at
ground potential and is not to carry current under normal operating
E-184.108.40.206 Continuously energized parts, such as positive battery
terminals and both ends of all wire connected thereto, shall be
physically protected with boots, or other form of protection, that cover
all energized surfaces to prevent accidental short circuits.
EXCEPTION: Circuits that have overcurrent protection at the source of
power in accordance with E-9.12.
E-9.6.1 Marking - Switches and electrical controls shall be marked to
indicate their usage.
EXCEPTION: A switch or electrical control whose purpose is obvious, and
whose mistaken operation will not cause a hazardous condition.
E-9.6.2 Marking of Equipment - Electrical equipment, except a part of an
identified assembly, such as an engine, shall be marked or identified by
the manufacturer to indicate:
E-220.127.116.11 product identification;
E-18.104.22.168 DC electrical rating in volts;
NOTE: Rated amperage or wattage of electrical equipment may be marked on
the device. See E-9.6.3.
E-22.214.171.124 the terminal polarity or identification, if necessary to
E-126.96.36.199 "ignition protected," if applicable. This shall be
identified by a marking such as "SAE J1171-Marine," "UL
Marine Ignition Protected," or "Ignition Protected."
E-9.6.3 Rated amperage or wattage of electrical equipment shall be
available. See the note in E-188.8.131.52.
E-9.7.1 The ambient temperature of machinery spaces is considered to be
50°C (122°F), and of all other spaces is considered to be 30°C (86°F).
E-9.8.1 Electrical sources of ignition located in spaces containing
gasoline powered machinery, or gasoline fuel tank(s), or joint fitting(s),
or other connection(s) between components of a gasoline system shall be
ignition protected, unless the component is isolated from a gasoline
fuel source as described in E-9.8.3. See Figure 3 through 10.
EXCEPTION: 1. Boats using diesel fuel as the only fuel source.
2. Outboard engines mounted externally or in compartments open to the
atmosphere in accordance with the requirements of ABYC H-2, Ventilation
of Boats Using Gasoline.
E-9.8.2 If LPG or CNG is provided on the boat, all electrical sources of
ignition located in a compartment containing LPG or CNG appliances,
cylinders, fittings, valves, or regulators shall be ignition protected.
EXCEPTION: For boats with LPG or CNG systems installed in accordance
with the requirements of ABYC A-1, Marine Liquefied Petroleum Gas (LPG)
Systems, or ABYC A-22, Marine Compressed Natural Gas (CNG) Systems, and
stoves complying with ABYC A-3, Galley Stoves, electrical devices in the
following compartments are excepted:
1. Accommodation spaces.
2. Open compartments having at least 15 square inches (970cm2) of open
area per cubic foot (0.28cm3) of net compartment volume exposed to the
atmosphere outside of the craft.
E-9.8.3 An electrical component is isolated from a gasoline fuel source
E-184.108.40.206 a bulkhead that meets the requirements of E-9.8.4 (see Figure
9 and Figure 10) is between the electrical component and the gasoline
fuel source, or
E-220.127.116.11 the electrical component is
E-18.104.22.168.1 lower than the gasoline fuel source, and a means is provided
to prevent gasoline fuel and gasoline fuel vapors that may leak from the
gasoline fuel sources from becoming exposed to the electrical component;
E-22.214.171.124.2 higher than the gasoline fuel source, and a deck or other
enclosure is between it and the gasoline fuel source; or
E-126.96.36.199.3 the distance between the electrical component and the fuel
source is at least two feet (610mm), and the space is open to the
atmosphere. See Figure 8.
E-9.8.4 Each bulkhead required by E-188.8.131.52 (see Figure 9 and Figure 10)
E-184.108.40.206 separate the electrical component from the fuel source, and
extend, both vertically and horizontally, the distance of the open space
between the gasoline fuel source and the ignition source, and
E-220.127.116.11 resist a water level that is 12 inches (305mm) high, or
one-third of the maximum height of the bulkhead, whichever is less,
without seepage of more than one-quarter fluid ounce (7.4cc) of fresh
water per hour, and
E-18.104.22.168 have no opening higher than 12 inches (305mm), or one-third
the maximum height of the bulkhead, whichever is less, unless the
opening is used for the passage of conductors, piping, ventilation
ducts, mechanical equipment, and similar items, or doors, hatches, and
access panels; and the maximum annular space around each item or door,
hatch or access panel shall not be more than one-quarter inch (6mm).
E-9.8.5 To minimize the potential for migration of carbon monoxide from
machinery compartments containing gasoline engines to adjacent
accommodation compartments, bulkhead and deck penetrations shall be in
accordance with the requirements of ABYC H-2, Ventilation of Boats Using
NOTE: For additional information see ABYC T-22, Educational Information
About Carbon Monoxide; and ABYC TH-23, Design, Construction, and Testing
of Boats in Consideration of Carbon Monoxide.
E-9.10 BATTERY CAPACITY
E-9.10.1 The battery, or battery bank, shall have at least the cold
cranking amperage required by the engine manufacturer.
E-9.10.2 The battery, or battery bank, shall have a rated reserve
capacity so that,
E-22.214.171.124 for boats with one battery charging source the battery shall
be capable of supplying the total load of Column A in Table I for a
minimum of 1 1/2 hours; or
E-126.96.36.199 for boats with multiple simultaneous battery charging
sources, the capacity of all charging sources, except the largest
charging source shall be subtracted from the total load of Column A. The
battery shall be capable of supplying the resulting differences for a
minimum of 1 1/2 hours.
E-188.8.131.52 Use Table II for reserve capacity values, or the following
formula derived from Peukert's equation to calculate the required
T = 0.0292 x I 1.225 x 60
= battery reserve capacity in minutes
I = total current of column A in amperes per E-9.9.1
E-9.11 DC POWER SOURCES
E-9.11.1 Overcurrent Protection Device Location - Ungrounded conductors
shall be provided with overcurrent protection within a distance of 7
inches (175mm) of the point at which the conductor is connected to the
source of power measured along the conductor. See Figure 11.
EXCEPTIONS: 1. Cranking motor conductors.
2. If the conductor is connected directly to the battery terminal and is
contained throughout its entire distance in a sheath or enclosure such
as a conduit, junction box, control box or enclosed panel, the
overcurrent protection shall be placed as close as practicable to the
battery, but not to exceed 72 inches (1.83m).
3. If the conductor is connected to a source of power other than a
battery terminal and is contained throughout its entire distance in a
sheath or enclosure such as a conduit, junction box, control box or
enclosed panel, the overcurrent protection shall be placed as close as
practicable to the point of connection to the source of power, but not
to exceed 40 inches (1.02m).
NOTE: See Section E-9.17, Installation.
E-9.11.2 Battery Charging Sources
E-184.108.40.206 Each ungrounded conductor connected to a battery charger,
alternator, or other charging source, shall be provided with overcurrent
protection within a distance of 7 inches (175mm) of the point of
connection to the DC electrical system or to the battery.
EXCEPTIONS: 1. If the conductor is connected directly to the battery
terminal and is contained throughout its entire distance in a sheath or
enclosure such as a conduit, junction box, control box or enclosed
panel, the overcurrent protection shall be placed as close as
practicable to the battery, but not to exceed 72 inches (1.83m).
2. If the conductor is connected to a source of power other than a
battery terminal and is contained throughout its entire distance in a
sheath or enclosure such as a conduit, junction box, control box or
enclosed panel, the overcurrent protection shall be placed as close as
practicable to the point of connection to the source of power, but not
to exceed 40 inches (1.02m). Overcurrent protection is not required in
conductors from self-limiting alternators with integral regulators if
the conductor is less than 40 inches (1.02m), is connected to a source
of power other than the battery, and is contained throughout its entire
distance in a sheath or enclosure.
E-220.127.116.11 In addition to the provisions of E-18.104.22.168, the ungrounded
conductor shall be provided with overcurrent protection within the
charging source, or within 7 inches (175mm) of the charging source,
based on the maximum output of the device.
EXCEPTION: Self-limiting devices.
E-9.11.3 Battery Switch
E-22.214.171.124 A battery switch shall be installed in the positive
conductor(s) from each battery or battery bank with a CCA rating greater
than 800 amperes.
EXCEPTIONS: 1. Trolling motor conductors connected to dedicated trolling
motor batteries provided with overcurrent protection at the battery and
a manual means of electrical disconnect separate from the trolling motor
2. Conductors supplying the following may be connected to the battery
side of the switch (see Figure 12):
a. Electronic equipment with continuously powered memory;
b. Safety equipment such as bilge pumps, alarms, CO detectors and bilge
c. Battery charging equipment.
E-126.96.36.199 A battery switch shall be mounted in a readily accessible
location as close as practicable to the battery.
E-188.8.131.52 Battery Switch Ratings - The intermittent rating of a battery
switch shall not be less than the maximum cranking current of the
largest engine cranking motor that it serves. The minimum continuous
rating of a battery switch shall be the total of the ampacities of the
main overcurrent protection devices connected to the battery switch, or
the ampacity of the feeder cable to the switch, whichever is less.
E-9.12.1 Motors or Motor Operated Equipment - Motors and motor operated
equipment, except for engine cranking motors, shall be protected
internally at the equipment, or by branch circuit overcurrent protection
devices suitable for motor current. The protection provided shall
preclude a fire hazard if the circuit, as installed, is energized for
seven hours under any conditions of overload, including locked rotor.
NOTES: 1. It may be necessary to use thermally responsive protection
devices on the equipment or system if the motor is not capable of
operating continuously at maximum possible loading.
2. It may be necessary to test as installed in order to assure
compliance with the locked rotor requirement. Voltage drop, due to wire
size, and delay characteristics of the overcurrent protection device may
have to be adjusted to protect the motor.
E-9.12.2 Non-motor Loads - The rating of overcurrent protection devices
used to protect a load other than a DC motor shall not exceed 150
percent of the ampacity of its supply conductor. See Table IV.
E-9.12.3 Branch Circuits
E-184.108.40.206 Each ungrounded conductor of a branch circuit shall be
provided with overcurrent protection at the point of connection to the
main switchboard unless the main circuit breaker or fuse provides such
E-220.127.116.11 Each fuse or trip-free circuit breaker shall be rated in
accordance with E-9.12.1 and E-9.12.2 and shall not exceed 150 percent
of the conductor ampacity in Table IV. See Figure 12.
E-9.12.4 Panelboards and Switchboards - A trip-free circuit breaker or a
fuse shall be installed at the source of power for panelboards and
switchboards, and shall not exceed 100 percent of the load capacity of
that panel, or 100 percent of the current carrying capacity of the
EXCEPTION: The trip free circuit breaker or fuse at the source of power
may be rated at up to 150 percent of the conductor ampacity if there is
a sub-main circuit breaker or fuse in the panelboard or switchboard that
is rated at no more than 100 percent of the load capacity, or the feeder
ampacity, whichever is less. See Figure 13.
E-9.12.5 Circuit Breakers
E-18.104.22.168 Circuit breakers installed in spaces requiring ignition
protection shall comply with SAE J1171, External Ignition Protection of
Marine Devices, or UL 1500, Ignition Protection Test for Marine
Products. If internal explosion tests are required, the ignition of the
test gas shall be created at 4 times the current rating of the device
E-22.214.171.124 Circuit breakers shall
E-126.96.36.199.1 have a DC voltage rating of not less than the nominal
system voltage, and
E-188.8.131.52.2 be of the trip-free type, and
E-184.108.40.206.3 be capable of an interrupting capacity according to Table
III, and remain operable after the fault,
EXCEPTION: Integral overcurrent protection in electrical devices.
NOTES: 1. A fuse in series with, and ahead of the circuit breaker, may
be used to comply with Table III.
2. Consult the circuit breaker manufacturer to determine the fuse size
and the type of fuse.
E-220.127.116.11.4 be of the manual reset type except as provided in E-9.12.7.
E-18.104.22.168 Fuses shall have a voltage rating of not less than the
nominal system voltage.
E-22.214.171.124 Fuses installed in spaces requiring ignition protection shall
comply with SAE J1171, External Ignition Protection for Marine Devices,
or UL 1500, Ignition Protection Test for Marine Products. If internal
explosion tests are required, the ignition of the test gas shall be
created at four times the rating of the fuse.
E-9.12.7 Integral Overcurrent Protection Devices - Integral overcurrent
protection devices without a manual reset may be used as an integral
part of an electrical device provided the rest of the circuit is
protected by a trip-free circuit protection device(s) or a fuse(s).
E-9.12.8 Pigtails - Pigtails less than 7 inches (175mm) in length are
exempt from overcurrent protection requirements.
E-9.13.1 If single pole switches are used in branch circuits they shall
be installed in the positive conductor of the circuit.
EXCEPTIONS: 1. Engine mounted pressure, vacuum, and temperature operated
2. Switches such as those used for control of alarm systems.
E-9.13.2 Switches shall have voltage ratings not less than the system
voltage, current ratings not less than the connected load, and shall be
rated for the type of load, i.e., inductive or resistive.
EXCEPTION: Battery switches. See E-126.96.36.199.
APPLIANCES AND EQUIPMENT
E-9.14.1 Appliances and fixed DC electrical equipment shall be designed
so that the current carrying parts of the device are insulated from all
exposed electrically conductive parts.
EXCEPTIONS: 1. 12 volt equipment not located in machinery spaces, not in
contact with bilge, and not in contact with a fuel line.
2. Communications and audio equipment
3. Electric navigation equipment
4. Instruments and instrument clusters
5. Liquid level gauge transmitters. For installation of fuel tank
transmitters on conductive surfaces. See E-9.14.4.
6. Navigation lights operating at nominal 12 volts. See ABYC A-16,
Electric Navigation Lights.
7. Auxiliary generator sets
8. Engine mounted equipment. See E-9.5.1.
E-9.14.2 Devices subject to exceptions 1 through 8 in E-9.14.1 shall be
installed with the case negative, and the positive connection shall be
E-9.14.3 All exposed electrically conductive non-current carrying parts
of fixed DC electrical equipment, and appliances that may normally be in
contact with bilge water or seawater, shall be connected to the DC
EXCEPTIONS: 1. Boats not equipped with a DC grounding system.
2. Equipment with an effective double insulation system.
3. Metal parts isolated in non-conductive material
4. Electric trolling motors
E-9.14.4 Grounded Liquid Level Gauge Transmitters (senders) - Grounded
liquid level gauge transmitters mounted on fuel tanks or tank plates
shall have the transmitter negative return conductor connected directly
to the DC main negative bus, the engine negative terminal, or for
outboard boats the battery negative terminal or its bus. No other device
shall be connected to this conductor. This conductor shall also serve as
the static ground and/or the bonding conductor for the tank and fill. If
a fuel tank is included in the lightning protection system the conductor
between the fuel tank and the DC main negative bus shall meet the
requirements of ABYC E-4, Lightning Protection.
E-9.15.8 Conductors used for panelboard or switchboard main feeders,
bilge blowers, electronic equipment, navigation lights, and other
circuits where voltage drop must be kept to a minimum, shall be sized
for a voltage drop not to exceed 3 percent. Conductors used for
lighting, other than navigation lights, and other circuits where voltage
drop is not critical, shall be sized for a voltage drop not to exceed 10
E-9.16.1 Each electrical conductor that is part of the boat's electrical
system shall have a means to identify its function in the system.
EXCEPTION: Pigtails less than 7 inches (175mm) in length.
E-9.16.2 Insulated grounding conductors shall be identified by the color
green or green with yellow stripe(s).
E-9.16.3 The color code shown in Table XI identifies colors for DC
conductors used for general wiring purposes on boats.
E-9.16.4 The color code shown in Table XII identifies one selection of
colors for use as an engine accessory wiring color code. Other means of
identification may be used providing a wiring diagram of the system
indicating the method of identification is provided with each boat.
E-188.8.131.52 Color coding may be accomplished by colored sleeving or color
application to wiring at termination points.
E-184.108.40.206 If tape is used to mark a wire, the tape shall be at least
3/16 inch (5mm) in width, and shall have sufficient length to make at
least two complete turns around the conductor to be marked. The tape
shall be applied to be visible near each terminal.
E-9.17.1 Wiring shall be installed in a manner that will avoid magnetic
loops in the area of the compass and magnetically sensitive devices.
Direct current wires that may create magnetic fields in this area shall
run in twisted pairs.
E-9.17.2 Junction boxes, cabinets, and other enclosures in which
electrical connections are made, shall be weatherproof or installed in a
protected location to minimize the entrance or accumulation of moisture
or water within the boxes, cabinets, or enclosures.
E-9.17.3 In wet locations, metallic junction boxes, cabinets, or
enclosures shall be mounted to minimize the entrapment of moisture
between the box, cabinet, or enclosure and the adjacent structure. If
air spacing is used to accomplish this, the minimum spacing shall be 1/4
E-9.17.4 Current carrying conductors shall be routed as high as
practicable above the bilge water level and other areas where water may
accumulate. If conductors must be routed in the bilge, or other areas
where water may accumulate, the wiring and connections shall be
E-9.17.5 Conductors shall be routed as far away as practicable from
exhaust pipes and other heat sources. Unless an equivalent thermal
barrier is provided, a clearance of at least 2 inches (51mm) between
conductors and water cooled exhaust components, and a clearance of at
least 9 inches (230mm) between conductors and dry exhaust components,
shall be maintained. Conductors shall not be routed directly above a dry
EXCEPTIONS: 1. Wiring on engines.
2. Exhaust temperature sensor wiring.
E-9.17.6 Battery cables without overcurrent protection shall comply with
E-220.127.116.11 Battery cables shall be routed above normal bilge water
levels throughout their length;
E-18.104.22.168 Battery cables shall be routed to avoid contact with metallic
fuel system components;
E-22.214.171.124 The ungrounded battery cable shall be routed to avoid contact
with any part of the engine or drive train.
E-9.17.7 Conductors that may be exposed to physical damage shall be
protected by self-draining loom, conduit, tape, raceways, or other
equivalent protection. Conductors passing through bulkheads or
structural members shall be protected to minimize insulation damage such
as chafing. Conductors shall also be routed clear of sources of chafing
such as steering cable and linkages, engine shafts, and throttle
E-9.17.8 DC conductors shall be sheathed, bundled, or otherwise kept
separate from AC conductors.
E-9.17.9 Conductors shall be at least 16 AWG.
EXCEPTIONS: 1. 18 AWG conductors may be used if included with other
conductors in a sheath, and do not extend more than 30 inches (760mm)
outside the sheath.
2. Conductors having a current flow of less than one amp in
communication systems, electronic navigation equipment and electronic
3. Conductors that are totally inside an equipment housing.
E-9.17.10 Conductors shall be supported throughout their length or shall
be secured at least every 18 inches (455mm) by one of the following
E-126.96.36.199 By means of non-metallic clamps sized to hold the conductors
firmly in place. Non-metallic straps or clamps shall not be used over
engine(s), moving shafts, other machinery or passageways, if failure
would result in a hazardous condition. The material shall be resistant
to oil, gasoline, and water and shall not break or crack within a
temperature range of -34°C (-30°F) to 121°C (250°F);
E-188.8.131.52 By means of metal straps or clamps with smooth, rounded
edges to hold the conductors firmly in place without damage to the
conductors or insulation. That section of the conductor or cable
directly under the strap or clamp shall be protected by means of loom,
tape or other suitable wrapping to prevent injury to the conductor;
E-184.108.40.206 By means of metal clamps lined with an insulating material
resistant to the effects of oil, gasoline, and water.
EXCEPTIONS: Exception to E-9.17.10:
1. Battery cables within 36 inches (910mm) of a battery terminal.
2. Cables attached to outboard motors.
E-9.17.11 All electrical appliances and equipment designed for permanent
installation shall be securely mounted to the boat's structure.
E-9.17.12 Wiring Connections
E-220.127.116.11 All connections shall be in locations protected from the
weather, or in weatherproof enclosures, or shall be watertight. If
connections are exposed to immersion they shall be watertight.
E-18.104.22.168 Wiring connections shall be designed and installed to make
mechanical and electrical joints without damage to the conductors.
E-22.214.171.124 Metals used for terminal studs, nuts, and washers shall be
corrosion resistant and galvanically compatible with the conductor and
terminal lug. Aluminum and unplated steel shall not be used for studs,
nuts, and washers.
E-126.96.36.199 Each conductor splice joining conductor to conductor,
conductor to connectors, and conductor to terminals shall be able to
withstand a tensile force equal to at least the value shown in Table
XIII for the smallest conductor size used in the splice for a one minute
duration and not break.
E-188.8.131.52 Terminal connectors shall be the ring or captive spade
types. See Figure 14.
EXCEPTION: Friction type connectors may be used if
a. the voltage drop from terminal to terminal does not exceed 50
millivolts for a 20 amp current flow, and
b. the connection does not separate if subjected to a six pound (2.75kg)
tensile force along the axial direction of the connector for one minute.
E-184.108.40.206 Connections may be made using a set screw pressure type
conductor connector providing a means is used to prevent the set screw
from bearing directly on the conductor strands.
E-220.127.116.11 Twist-on connectors, i.e., wire nuts, shall not be used.
E-18.104.22.168 Solder shall not be the sole means of mechanical connection
in any circuit. If soldered, the connection shall be so located or
supported as to minimize flexing of the conductor where the solder
changes the flexible conductor into a solid conductor.
EXCEPTION: Battery lugs with a solder contact length of not less than
1.5 times the diameter of the conductor.
NOTE: When a stranded conductor is soldered, the soldered portion of the
conductor becomes a solid strand conductor and flexing can cause the
conductor to break at the end of the solder joint unless adequate
additional support is provided.
E-22.214.171.124 Crimp-on connectors shall be attached with crimping tools
designed for the connector used, and to produce a connection that meets
the requirements of E-126.96.36.199.
E-188.8.131.52 No more than four conductors shall be secured to any one
terminal stud. If additional connections are necessary, two or more
terminal studs shall be connected together by means of jumpers or copper
E-184.108.40.206 Ring and captive spade type terminal connectors shall be
the same nominal size as the stud.
E-220.127.116.11 Conductors terminating at switchboards, in junction boxes,
or fixtures shall be arranged to provide a length of conductor to
relieve tension, to allow for repairs, and to permit multiple conductors
to be fanned at terminal studs.
E-18.104.22.168 The shanks of terminals shall be protected against
accidental shorting by the use of insulation barriers or sleeves.
EXCEPTION: The shanks of terminals used in grounding systems.
E-9.18.1 Receptacles installed in locations subject to rain, spray, or
splash shall be weatherproof when not in use.
NOTE: Weatherproofing may be provided by means such as spring-loaded,
self-closing, or snap-type receptacle covers.
E-9.18.2 Receptacles installed in areas subject to flooding or momentary
submersion shall be of a watertight design, the integrity of which is
not affected when the receptacle is in use.
E-9.18.3 Receptacles and matching plugs used on DC systems shall not be
interchangeable with receptacles and matching plugs used elsewhere on
the boat for AC systems.
E-9.19.1 Multi-wire plugs and receptacles used in conjunction with
harness type wiring systems shall comply with the following:
E-22.214.171.124 Plugs and receptacles shall incorporate means, such as cable
clamps, molded connectors, insulation grips, extended terminal barrels,
etc., for supporting all wires to limit flexing at the connection, and
E-126.96.36.199 plugs and receptacles exposed to weather shall be
weatherproof, or if subject to immersion, shall be watertight.
E-9.19.2 Each terminal in a multi-wire plug and receptacle shall be
protected from accidental short-circuiting to adjacent terminals.
E-9.19.3 Plug connectors shall have a minimum disengagement force of 6
pounds (2.75kg) along the axial direction of the connector for one
E-9.19.4 The plug connector's capacity shall be selected to meet or
exceed the ampacity and temperature rating of the connecting conductors
in addition to its wire size capability.
MAIN SWITCHBOARD OR PANELBOARD
E-9.20.1 A main switchboard or panelboard shall be installed in a
readily accessible location, and shall be weatherproof or protected from
the weather and splash.
E-9.20.2 Switchboards and panelboards used on boats with more than one
system voltage shall have a permanent marking showing the system voltage
and its type (DC).
E-9.20.3 Switchboards and panelboards shall be designed so that there
are no exposed energized AC parts accessible to the operator when the DC
panel is open.
DC GROUNDING AND BONDING
E-9.21.1 DC Grounding - If a DC grounding system is installed, the DC
grounding conductor shall be used to connect metallic non-current
carrying parts of those direct current devices identified in E-9.14.3 to
the engine negative terminal or its bus for the purpose of minimizing
stray current corrosion. See Figure 15.
NOTE: This system is the DC grounding system formerly published as ABYC
E-1, Bonding of Direct Current Systems.
E-9.21.2 DC Grounding Conductor
E-188.8.131.52 A DC grounding conductor shall not be smaller than one size
under that required for current carrying conductors supplying the device
and not less than 16 AWG. See Figure 15 and Figure 16.
E-184.108.40.206 Routing - The DC grounding conductor shall be routed from the
device to the engine negative terminal or the DC main negative bus by
one of the following means:
E-220.127.116.11.1 The DC grounding conductor shall be routed together with
the current carrying conductors as a third wire;
E-18.104.22.168.2 The DC grounding conductor shall be routed as a separate
E-22.214.171.124 The DC grounding conductor shall be connected to a DC
grounding bus in accordance with E-9.21.5.
E-126.96.36.199 Connections - DC grounding conductor connections shall be
made in accordance with E-9.17.12.
E-9.21.5 DC Grounding Bus
E-188.8.131.52 The DC grounding bus shall be connected directly to the
engine negative terminal or the DC main negative bus.
E-184.108.40.206 The DC grounding bus serving more than one electrical device
shall comply with E-9.21.2 for the largest device, and shall be
manufactured and installed in accordance with the following:
E-220.127.116.11.1 If the DC grounding bus is fabricated from copper or bronze
strip, it shall have a thickness not less than 1/32 inch (0.8mm) and a
width of not less than 1/2 inch (13mm); and
E-18.104.22.168.1.1 shall be drilled and tapped providing its thickness
ensures no less than three full threads of engagement for the terminal
E-22.214.171.124.1.2 shall be through-drilled, and the connections made with
machine screws and locknuts.
NOTE: Copper pipe may be used providing its wall thickness is sufficient
for the pipe to be drilled and tapped as required above.
E-126.96.36.199.2 Copper braid shall not be used.
E-9.21.6 Combined DC Grounding and Bonding Systems - The DC grounding
conductors may be combined with the following systems providing all the
requirements with respect to conductor size are met for each system. See
Figure 15, Figure 16 and Figure 17.
E-188.8.131.52 Lightning Protection - See ABYC E-4, Lightning Protection.
E-184.108.40.206 Cathodic Bonding - See ABYC E-2, Cathodic Protection.
E-220.127.116.11 Static Electricity Grounding - See E-9.14.4, ABYC H-24,
Gasoline Fuel Systems, and ABYC H-33, Diesel Fuel Systems.
E-9.21.7 Radio Ground Plate - If the radio ground plate is connected to
the engine negative terminal, the connecting conductor shall meet the
requirements of ABYC E-4, Lightning Protection, since a radio ground
plate may also function as a lightning ground plate.
E-9.21.8 Coaxial Cables and Conduit - The metallic braid of coaxial
cables and metal conduit used for radio interference, or any form of
radio shielding or armoring, shall be connected to earth ground with an
insulated stranded copper conductor.
TABLE III - CIRCUIT BREAKER MINIMUM AMPERE INTERRUPTING CAPACITY
Ampere Interrupting Capacity (AIC)
(amperage available at circuit breaker terminals)
Total Connected Battery
(Cold Cranking Amperes) Main Circuit Breaker
*See Note Branch Circuit Breaker
12 Volts 650 or less 1500 750
and 651-1100 3000 1500
24 Volts over 1100 5000 2500
32 Volts 1250 or less 3000 1500
over 1250 5000 2500
*NOTE: The main circuit breaker(s) is considered to be the first
breaker(s) in a circuit connected in series with the battery. All
subsequent breakers, including sub-main breakers, connected in series
with a main circuit breaker shall be considered to be branch circuit
breakers. See Figure 12.
XI - WIRING COLOR CODE
Green, or green w/yellow stripe(s) DC grounding conductors
Black, or yellow DC negative conductors
Red DC positive conductors
TABLE XII - ENGINE AND ACCESSORY WIRING COLOR CODE
w/red stripe (YR)
Starting switch to solenoid
stripe (BY) or
Yellow (Y) - see note
Fuse or switch to blowers
Fuse or switch to lights
Tachometer sender to gauge
Generator armature to regulator
Alternator charge light
Auxiliary terminal to light to regulator
Fuse or switch to pumps
Ammeter to alternator or generator output and accessory fuses or
Distribution panel to accessory switch
ignition switch to coil and electrical instruments.
Instrument feed Distribution panel to electric instruments
Cabin and instrument lights
Fuse or switch to lights
blue (Lt Bl)
Oil pressure sender to gauge
Water temperature sender to gauge
Fuel gauge sender to gauge
Tilt down and/or trim in
Tilt and/or trim circuits
Tilt up and/or trim out
Tilt and/or trim circuits
NOTE: If yellow is used for DC negative, blower must be brown with
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