Installation Manual
N40475 Chapter 8
Page 45
Typical system in common use
The bonding system in the boat should provide a low
resistance connection between all metals in contact
with sea water, together with a connection to a Zinc
sacricial anode which is xed to the outside of the
hull below sea level.
The bonding should consist of heavy stranded
wire (not braiding or wire with ne strands). It is an
advantage if the wire is tinned. Insulation is also an
advantage and should preferably be green in colour.
Although the current carried by the bonding system
will not normally exceed 1 amp, the cable sizes should
be generous as shown in the table below:
Length of run to
Zinc Anode
Suggested cable size
Up to 30 feet
30 - 40 feet
7 strand / 0.85mm (4mm
2
)
7 strand / 1.04mm (6mm
2
)
As many of the connections may be splashed with
sea water they should be soldered wherever possible
and clamped elsewhere, with the joint protected from
corrosion by neoprene paint, or a similar material, to
exclude water.
Figure 31 shows the main components.
(1) Engine.
(2) Propeller shaft.
(3) Sea cock.
(4) Zinc anode.
(5) Bonding stud.
(6) Common bonding wire.
(7) Through the hull metal ttings.
Optional sensors
• Throttle position.
• Fuel level.
• Transmission oil pressure.
• Transmission oil temperature.
• Exhaust gas temperature.
• Coolant level.
• Fuel temperature.
• Fuel supply pressure.
Figure 31