Corrosion is usually more prevalent in polluted or salt
water than in fresh water. It is also more likely to occur
when dockage is in an area with steel piers, large
metal boats, or where shore power is in use.
The entire 120 (220) volt circuitry, especially the shore
power cord, should be seasonally tested for proper
continuity by an experienced marine electri cian. This
will help detect any short, open wire, or ground fault.
Also, check the polarity indicator system for proper
B. Galvanic Corrosion
Galvanic corrosion results from a potential electrical
difference existing between dissimilar metals im-
mersed in a conductive solution (e.g., salt or brackish
water). If these metals touch or are otherwise electri-
cally connected, this potential difference produces an
electron ﬂow between them. The attack on the more
active metal is usually increased and the attack on the
less active metal is decreased, as compared to when
these metals are not touching.
(220) volt AC electrical power can be
dangerous. DO NOT attempt to service a
system unless you are familiar with, and
experienced in, performing such service.
H - 11 STRAY CURRENT CORROSION
C. Corrosion Prevention
Electrically induced underwater corrosion occasionally
affects boats and their related components. This is
referred to as “Stray Current Corro sion” and appears
as surface pitting or deterioration. Stray current
corrosion is the decomposition of chemical com-
pounds by electric current.
Anticorrosion anodes are attached to the bottom
of the gimbal housing of your stern drive or to the
transom and propeller shafts (inboards models)
to prevent corrosion to your electrical systems and
underwater parts. These anodes will be slowly eroded
away by galvanic action and require periodic inspec-
tion. Please refer to the section on “Anti-Corrosion
Anodes” in your engine manufacturer’s manual for
additional information. See Figure H2.
Stray current corrosion can be caused by surrounding
boats; an improperly wired battery/charger installation
or other boats that are in close proximity which have
electrical power leakages. Stern drive units are
especially vulnerable to stray current corrosion.
Periodically inspect the engine components to deter-
mine if corrosion damage exists. If stray current
corrosion damage is found, determine and correct the
cause of the stray current to prevent further damage.
Con sult an experi enced marine electrician or contact
your Four Winns dealer for assistance.
The use of some shore power battery chargers, while
the boat is in the water and the battery is connected to
the system, can cause stray current corrosion. Have
an experienced marine electri cian review any battery
charger installation to ensure a stray current corrosion
problem will not develop. An improper battery connec-
tion is a common cause of stray current corrosion.
Use only UL Marine-ignition protected battery
charger(s) designed to meet US Coast Guard
regulations for external ignition protection.
Figure H2: Inboard Transom & Shaft Anodes Shown
Electrical Systems - Section H
Owner’s Manual Page 84
|Categories||Four Winns Manuals, Four Winns V-Series Manuals|
|Tags||Four Winns V375|
|Document Type||Owner's Manual|
|Product Brand||Boats and Cruisers, Four Winns. For support contact your dealer at http://www.fourwinns.com/locate-dealer.aspx|
|Document File Type|
|Wikipedia's Page||Outboard Marine Corporation|
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