Installation Instructions
12.8.20
Kapitel/Chapter 6: Installation Instructions - Seite/Page 75
6.11.3.3 Disconnector - power source selector (three way cam switch)
A power source selector switch must be installed between the generator (or if applicable, AC-Control box) and the
ship's electrical supply system. This switch must ensure that all AC consumers can be switched off at once. This
switch should also be installed to keep the generator and shore (grid) power systems separate.
Fig. 6.11.3-1: 3-way cam switch
As disconnector a cam switch should be used. This
switch should have three positions: "Shore power" -
"OFF" - "Generator". If an (DC-AC) inverter is used, a
fourth position will be required.
0 Off
I Generator
II Shore power connection
III Inverter
Example
The cam-type switch must have 2 poles, so that "MP" and "phase" can be switched off.
If a 3-phase current system is also installed with the option of supplying from either the generator or shore power, an
additional switch must be installed to keep these systems separate.
An alternative to a manual rotating switch is an automatic power relay. When the generator is not running, the relay
remains in the shore power position. As soon as the generator is running, the power relay switches automatically to
the generator position.
It is necessary that the 3-phase AC and the single-AC have to be installed separately from each other.
6.12 Special recommendations
6.12.1 Water sensor
Especially at older generators it may occur that by a leak in the hose system raw water gets from the sea water
pump inito the generator. If a proper break is the cause, this may lead to considerable damages at the generator. To
prevent this, Fischer Panda offers a water sensor in his accessories program, which may be installed in the
generator. This sensor identifies the flooding and switches the generator off. The sensor should be installed as close
as possible to the capsule floor.
6.13 Instructions on prevention of galvanic corrosion
Galvanic corrosion
If several machines are connected by a common electrical potential (e.g. mass) and the system is also still in contact
with other metal parts (e.g. the hull of a neighbour ship), always assume that the different components proceed
different electrical voltage, which affect the entire system and the components. DC voltage causes an electric
current, if in the environment of these parts electrically leading liquids (electrolyte) are available. This is called
„galvanic process“. The electrical charge of the negatively charged fields (anode) is led to the positively charged field
(cathode). The negatively charged part (anode) „is sacrificed“ thereby, i. e. that the electrical particles at the surface
of the material caus decomposition with this chemical process. Since aluminium is an electrically negatively charged
metal, aluminium will play the role of the anode compared with most remaining metals. This applies in particular to
copper, brass, and also steel and stainless steel etc. These metals are positively charged.
