Volvo Penta 5.7 Gil-B, Operator'S Manual

Page: 58 / 70

56
Electrolytic Corrosion
To protect the propeller and underwater equipment
against galvanic corrosion your boat and its propulsion unit
have galvanic corrosion protection. Leakage current from
the electrical system will prevent this protection system
from working and may result in major damage to your boat
or other boats in your vicinity. Leakage current from the
electrical system can be caused by faulty equipment or
incorrect installation of electrical equipment.
Caution!
Electrolytic corrosion as a consequence of
leakage currents may cause serious damage to
your boat’s equipment within a short time. Work
on the boat’s low voltage circuit should only be
carried out by qualified/experienced personnel.
Installation or work on the shore power equip-
ment must only be carried out by electricians
authorized to work with high voltage installa-
tions.
The following should always be observed: Route and
clamp electric cables so that they will not be exposed to
damp or bilge water in the keelson. The main engine
switch must be connected to the positive (
+ ) terminal on
the battery, and must cut off all power consuming
equipment as soon as the engine is stopped. If an extra
battery has been installed then there must be separate
switches for extra equipment. There should also be a main
switch between the auxiliary battery positive terminal and
the electrical equipment fuse strip. The main switch for the
auxiliary battery must cut off all power consuming
equipment connected to that battery and be turned off
when power is no longer needed. The engine or drive
must not be electrically connected to other equipment
such as the trim plane, bathing steps etc. The engine and
transmission must not be used as ground points for radio
or navigation installations or other electrical equipment
with separate ground cables.
All separate ground cables
must have a common ground point, separated from the
engine and transmission. If shore power is connected, a
protective ground should not be connected to the engine
or to any other ground terminal on the boat. Transformers
connected to shore power must be installed so that the
protective ground on the input side (120/220 V) and the
negative connection on the output side (12 V) are not
connected.
For more detailed information on this subject, see the
section
Electrochemical corrosion in publication number
7733534 Marine Electrical Systems Part I.
Maintenance and Care