Specifications

OPERATION
EN / Mass Charger 24/15-2; 24/25-2; 24/25-2 DNV / March 2014 7
3 OPERATION
3.1 INTRODUCTION
The MASS battery charger is a full-automatic high
efficiency battery charger/rectifier, developed and
produced by Mastervolt The MASS series features a
family of advanced quality battery chargers. The Mass
Charger not only charges batteries rapidly and safely, it
supplies the connected consumers at the same time. In
addition, the Mass Charger is secured against short circuit,
overload and high temperatures in an industrial
environment.
3.1.1 Switching on
The battery charger will be switched on by the ON/OFF
switch. One of the front LEDs will light up now and the
charging starts immediately.
3.1.2 Switching off
The battery charger will be switched off by the ON/OFF
switch.
WARNING
Switching off the Mass Charger does not cut off
the connection to the batteries or the AC-
source. This means that voltages are still
available inside the apparatus.
3.2 THEORY OF OPERATION
The battery charger is equipped with an intelligent 3-stage
charge characteristic which takes care of an optimal
charge of your batteries (see fig. 2). When switched on,
the Mass Charger always starts at Bulk phase.
Fig. 2: Example: charge characteristic
To prevent your batteries from overcharging a new cycle
only starts when the battery voltage has been under the
level of 12.8/25.6 or 51.2V for longer than 30 seconds or
after a hard reset by switching the on/off switch back and
forward.
3.3 FRONT PANEL
See figure 3. On the front of the Mass Charger LED 9 to
13 represent the charging current. The more LEDs are
illuminated, the higher the charging current. LED 1-5
represent the charging state.
Illuminating
LED’s
Meaning
Normal operation, LED 6 illuminates green
1 Charger on, BULK stage
1+2 Uout> 27.6V
1+2+3
A
BSORPTION, Uout = abs. (28.5V)
1+2+3+4 3 hrs after start max bulk timer,
or I < return amps
1+2+3+4+5 FLOAT, 6 hrs after start max bulk timer,
or I < return amps for 15 min or longer
9 Charge current 0-5% of full current
9+10 Charge current 5-25% of full current
9+10+11 Charge current 25-50% of full current
9+10+11+12 Charge current 50-75% of full current
9+10+11+12+13 Charge current 75-100% of full current
6 Green: normal operation, Red: fault
condition, Off: standby or off
7 Green: MasterBus communication,
Off: no MasterBus communication
Fault condition, LED 6 illuminates red
6 red +1 Battery sense error
6 red +2 Charger temperature too high
6 red +3 Short circuit indication, charger will
reduce the charge current to 25%
6 red +4 DC error, DC voltage too low or too high
6 red +5 Temperature sense error
Fig 3: Front panel of the battery charger
LEDs in charge
stage, see fig. 5
charge
voltage (V)
charge
current (A)
charge time
BULK ABSORPTION FLOAT
1
2
3
4
5
full
100%
50%
30
28
26
24
22
20
0%