2.3 CABLING AND POWER SUPPLIES
2.3.1 SIGNAL CABLING
Cable inter-connections between system sub-
units are shown schematically in Figs. 2, and
3. The interconnecting multi-core cable
between the control unit and drive unit is 20
feet (6m) long, and is supplied with the control
unit. All other interconnecting cables are
supplied with their related sub-unit
and
are also
20feet (6m) in length. All 7 core cables are
supplied with pre-wired waterproof connectors
and are extendable in 20 feet (6m) increments
by the addition of standard cable extensions
(Cat. No.
as shown in Fig. 3.
Cable connector clamp nuts should be
securely tightened to ensure watertight joints.
All cables should be run at least 3ft (1 m) from
existing cables carrying radio frequency or
pulsed signals, and should be clamped at 1.5
foot
intervals.
2.3.2 DC SUPPLY CABLE
As a general rule the DC supply cable to the
drive unit should be kept as short as possible,
and have a conductor area of 1 sq.mm per
metre run to minimise voltage drop.
Example:
Length of cable Conductor area Cable size
Up to
2.5 sq.mm
4
The two supply cables must run directly from
the vessel’s battery or alternatively from the
main distribution panel, and a 20 amp fuse or
overload trip should be included in the circuit.
It is important not to tap into supplies to other
into supplies to other equipment to avoid the
possibility of mutual interference.
The drive unit is supplied with
power supply cable tails. These should be
connected to the main power supply cable via
a heavy-duty terminal block. The red cable tail
should be connected to the positive supply and
the black cable to the negative supply. If
polarity is accidentally reversed the equipment
will not operate, but no damage will result.
The drive unit case must be bonded to the
metal hull or engine frame and a heavy duty
conductor
should be used for this
purpose.
