Regal 42SC Owner's Manual page 66

DIRECT CURRENT (12 VOLTS)
Your Regal yacht uses 12 volt DC electricity otherwise
known as direct current. It is called DC because it fl ows
only one way in a circuit. Specifi cally to name a few,
helm gauges, batteries, battery cables, engine electrical
components, engine wiring harnesses, dash switches,
selected lighting, shower sump, bilge pumps, and vacuum
toilets are all components using a 12 volt DC system.
In the DC system used in the United States the red wire
is designated as the "hot" or conductor wire and the
black wire is referred to as the ground wire. At times
other current carrying wires are color coded such as blue
to identify their use as a low voltage conductor. This is
especially helpful in troubleshooting and adding additional
equipment. Be sure to review the wiring schematics in the
drawing section of the technical chapter.
Direct current is stored in the ship's batteries and produced
through the engine alternators while the engines are
running or by the battery charger at dockside.
The alternators charge the batteries by sending current
through the main distribution panel relays, battery switches
and harnesses to the appropriate battery. Normal DC
voltage is between 12 and 15 volts. Lower or higher
readings could indicate a charging malfunction or a weak
battery.
The Volvo diesel engine alternators used on your yacht are
internally self "excited" and produce DC current at idle.
Current specifi cations for alternator output is 115 amps.
The IPS steering system needs additional operating current
and this is one reason the alternator output is higher than
conventional units.
The port cranking battery controls the windlass, port
engine and generator.
The starboard battery controls the starboard engine
The house battery controls a variety of onboard
equipment.
BATTERY (12 VOLTS) DESCRIPTION
On board direct current is stored in the ship's "wet cell"
batteries. There are 2 engine starting batteries (one for each
engine) and a deep cycle "house" battery.
REMOVE
BATTERY
T Y P I C A L
ENGINE
STARTING
BATTERY
BATTERY SPECIFICATIONS
Battery
Group
Type
Engine
31A
Cranking
House 8D
BATTERY TERMINOLOGY
Group- Batteries are divided into groups which identify
the height, length, and width of the battery. This is useful
information should a replacement battery become neces-
sary.
Cold Cranking Amps (CCA)- This rating measures the
cranking power a full charged marine battery has available
to start at 32 degrees F. Basically, the higher the rating the
greater starting power of the battery.
Reserve Capacity (RC)- As usage on the boat increases
so does the need for more reserve capacity. The reserve
capacity represents the length of time in minutes a new
fully charged battery can maintain the yacht's electrical
needs without the engine running or in the event the al-
ternator fails.
13
Systems
TYPICAL
HOUSE
CAP
BATTERY
BOOT
CCA @32
Degrees F.
1260
1700
REMOVE
CAP
Reserve
Capacity
195 min.
430 min.