Kadey-Krogen Yachts 5814, Owner'S Manual, Page: 68 / 449

©2008 Kadey-Krogen Yachts, Inc.
www.kadeykrogen.com
Subject to change without notice.
Krogen 58’ Manual, Hull 58014 Bonding System
49
Bonding System
The bonding system on the Krogen 58’ is designed to be a common ground for the
vessel’s electrical and electronic equipment and systems, and as protection against both
corrosion by electrolysis and galvanic corrosion of components and fittings that directly
or indirectly come in contact with the sea.
The bonding system connects the main engines, Generators, fuel tank fills, fresh water
tank fills, waste discharge fittings, engine frames or enclosures, enclosures of electronic
devices, instrumental panels, rudder stuffing box and all thru-hulls. These items are
connected by No. 8 A.W.G bonding wire wrapped in green colored insulation for easy
identification. Also connected to this system is a 1/32” x ½” copper strip running Port
and Starboard from the Forward Machinery Space to Stern. Installed between the vessels
shore power and the bonding system are two NewMar® Model GI-50 Galvanic Isolators
designed to reduce stray low voltage current flowing between the AC safety ground and
DC bonding system. The final component of the bonding system is the connection of the
12V DC and 24V DC systems at a common grounding point terminal block located in the
Engine Room
. See Equipment List for complete list of Bonding System components.
Galvanic corrosion, often misnamed “electrolysis,” is one common form of corrosion in
marine environments. It occurs when two (or more) dissimilar metals are brought into
electrical contact under water. When a galvanic couple forms, one of the metals in the
couple becomes the
anode and corrodes faster than it would all by itself, while the other
becomes the cathode and corrodes slower than it would alone. Either, or both, metal in
the couple may or may not corrode by themselves in seawater. When contact with a
dissimilar metal is made, however, the self-corrosion rates will change: corrosion of the
anode will accelerate; corrosion of the cathode will decelerate or even stop. This is why
‘sacrificial’ zincs, or anodes, are placed on stainless steel propeller shafts and rudders.
A Galvanic Isolator is a device installed in
series with the grounding conductor of the
shore power cord and has two functions aboard a vessel. First, they protect against
galvanic corrosion by
blocking low voltage Direct Current (DC) galvanic current flow,
and second, permits the passage of Alternating Current (AC) normally associated with
the grounding conductor. There are no, and should not be any, circuit breakers connected
to the Galvanic Isolators. The two Galvanic Isolators are located in the Amidships
Machinery Space.
The Krogen 58’ is protected with two Shaft Brush Anodes, two Rudder Anodes per
rudder and one Hull Anode. Although not part of the Bonding System, ‘sacrificial’ zincs
are used in the cooling system of the propulsion engines, water heater, and the
Generators. The inspection and possible replacement of those anodes is covered in other
sections of this manual. The Stabilizers have two zinc anodes; one on each fin.