Specifications

INSTALLATION
10 March 2014 / Mass Charger 24/15-2; 24/25-2; 24/25-2 DNV / EN
4.3.2 AC safety grounding
WARNING!
The ground wire offers protection only if the
cabinet of the Mass Charger is connected to the
safety ground. Connect the ground terminal (PE
/ GND) to the hull or the chassis.
CAUTION!
For safe installation it is necessary to insert a
Residual Current Device (earth leakage switch)
in the AC input circuit of the Mass Charger.
4.3.3 DC wiring
Keep the cable connection between charger and batteries
shortest possible. If available, use coloured battery cables.
If this is not possible, mark the plus and the minus cables
with coloured insulating tape, e.g. red for plus and
blue/black for minus. Use the following diameters:
Model Mass Charger L <3 m Length 3-6 m
Mass 24/15-2 MB 6 mm² 10 mm²
Mass 24/25-2 MB 10 mm² 16 mm²
Mass 24/25-2 DNV MB 10 mm² 16 mm²
Connection of main batteries
1 Pull the cables through the cable glands of the Mass
Charger.
2 Crimp on the ring M6 terminals to the cable.
3 Connect the cables to the terminals of the Mass
Charger. Pay attention to the polarity, positive on
positive / negative on negative.
4 Integrate a suitable fuse (charger fuse) in the positive
cable. When using a DC distribution with fuses, no
additional fuse is necessary.
5 Cut the cables at length and crimp on the ring
terminals. Connect the cable to the DC distribution or
batteries.
CAUTION
Reversing the positive and negative battery
poles will severely damage the Mass Charger.
Too thin cables and/or loose connections can
cause dangerous overheating of the cables
and/or terminals.
Lay the positive and negative cables next to each other to
limit the electro magnetic field around the cables. The
negative cable should be connected directly to the
negative post of the battery bank or the ground side of a
current shunt. Do not use the hull or chassis frame as the
negative conductor.
4.4 BATTERY CAPACITY
Always follow the instructions published by battery
manufacturer. The minimum required battery capacity for
Mastervolt gel batteries is as follows:
Model Mass Charger Minimum required
battery capacity
Mass 24/15-2 MB 50 Ah
Mass 24/25-2 MB 60 Ah
Mass 24/25-2 DNV MB 60 Ah
4.5 BATTERY ISOLATOR
If one or more batteries or battery sets must be charged at
the same time via one output, a battery isolator should be
used. It isolates the different battery sets from one
another, in order to prevent one discharging the other. A
consequence of the battery isolator is a voltage drop of 0.6
Volt. This voltage drop can be compensated in two ways:
1 By changing DIP-switch 4 to On (Diode enabled);
2 By using the voltage sense function (see section 4.8);
CAUTION
Never use both methods. Your batteries will be
overcharged and severely damaged!
Mastervolt offers several Battery Isolators, refer to
www.mastervolt.com.
For a proper installation, see also the connection diagram
included with the battery isolator.
Steps:
1 Check if the Mass Charger, the main supply and the
DC distribution are switched off.
2 Check if the Dc fuses have been removed.
3 Connect the battery isolator(s) using cables with the
same diameter as the battery cables.
4 Compensate the voltage drop over the battery isolator
by changing the setting of dip switch 4 (see fig. 7).
5 Switch on the Mass Charger.