INSTALLATION
US / M-SQ7 / October 2010
17
1 FUSE
An output fuse (from the generating set to the system)
should be installed to protect the installed electrical
system. The following maximum single phase output
current applies:
Model
Maximum single phase
output current
120V 240V
M-SQ7
58 Amps
29 Amps
The fuses must be of the slow reacting type. For electrical
motors connected to the system, a motor protection switch
must be installed
2 GROUNDING
With the U.S.A. models neutral of the AC
alternator is grounded. The housing of the
alternator and all other metal parts are
grounded as well.
The connection between “neutral” and “ground” is
necessary as part of a insulation failure protection system
as commonly used in the U.S.A.
WARNING
In all situations the transfer switches between
shore, inverter and generator should switch all
connections, the phase line (L) as wel as
neutral (N). Off course this is the case when
using a Masterswitch.
For safety reasons connect the main ships ground to
negative point of the generating set start battery. When a
ungrounded DC system or positive grounded DC system is
applied the battery negative should not be connected to
the main ships ground.
3 CABLE
For the power cable we recommend the use of 4 wire oil
resistant cable with a sufficient cross sectional area. One
wire for earth is included. For long cables it is
recommended to apply cables with a larger cross section
(refer to ISO 13297 annex A).
4 TRANSFER
SWITCH
A power source selector switch much be installed between
the generating set 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 generating set and shore (grid) power systems
separate.
Transfer switches - to switch over from shore to ship or
from generating set to inverter - should be well designed to
switch over all wires including neutral (and not only phases
or line) and there should be provisions with the aid of
timers to prevent relays from clattering.
WhisperPower recommends the installation of a
Masterswitch as the power source selector. This works
automatically when the generating set is not running the
input remains in the shore position and as soon as the
generating set is running the Masterswitch switches
automatically after 10 seconds delay time over to the
generating set position.
