12
Mass Combi Pro 12/3000-150, 24/3500-100
– User and Installation Manual
4.2
Protections
The Mass Combi Pro is protected against overload, short
circuit, overheating and under and over voltage. You can
detect failures from the front panel or from the MasterBus
control panel.
CAUTION!
The Mass Combi Pro is not protected against
reversing polarity of the DC-input, AC voltage on
the DC-input and extreme over voltage (>300
VAC ) on the AC-input or AC-outputs.
4.2.1
Output overload or short circuit
In case of overload or short circuit during inverter mode,
the Power bar top LED illuminates red and the output
voltage of the Mass Combi Pro is limited. Mass Combi Pro
shuts down if this overload or short circuit lasts over 5
seconds. The Mass Combi Pro will automatically restart
after shutdown. After 5 failed start attempts the Mass
Combi Pro shuts down permanently, the Power bar top
LED and the Charge bar bottom LED stay blinking red. You
can restart the Mass Combi Pro only by switching the unit
manually off and on with the main switch on the Mass
Combi Pro after the overload or short circuit is removed.
4.2.2
Overheating
In the event of overheating the Mass Combi Pro inverter
shuts down, the charger reduces charge current.
Overheating is most likely caused by:
heavy or non-resistive loads operating for a longer
period;
high ambient temperature;
disrupted air flow (dust or too little space).
As soon as the temperature drops below the factory default
threshold, the inverter is powered up automatically or the
charger resumes its charge current.
4.2.3
Under and over voltage
The AC-input of the Mass Combi Pro is, within limits,
protected
against
over
and
under
voltage.
See
specifications. If the AC-input voltage is out of operating
range, the Mass Combi Pro will switch to inverter mode,
disconnecting both AC inputs and it will switch back if the
AC-input voltage is within range again. The DC-input of the
Mass Combi is also protected against over and under
voltage. See specifications. The Mass Combi Pro switches
off if the DC-input voltage is out of range.
4.2.4
Dynamic DC input window
Figure 4-2: Dynamic DC input window
The Dynamic DC input window is used to switch off
depending on both the battery voltage and current. The
reason for this is that low current loads cause a small
voltage drop but they are responsible for severe battery
damage.
Shown in figure 4-2 is the graph for a 24 V lead acid
battery. The graph shows three lines:
(1) Low voltage switch on. Above this voltage the inverter
switches on.
(2) Low voltage switch off with delay. Below this line the
inverter switches off after a delay.
(3) Low voltage switch off without delay. Below this line
the inverter switches off without delay.
4.3
Operation policies
Via MasterBus configuration, the preferred behaviour of AC
in and outputs can be set.
4.3.1
AC input policy
Preference
Description
Mains preferent
Mains input is preferred
Gen preferent
Generator input is preferred
Max fuse preferent
AC source with highest fuse setting
Mains only
No generator
Generator only
No mains
4.3.2
AC Output-2 policy
Preference
Description
Events only
Operation manually
Generator input
Generator input only
Mains input
Mains input only
Gen/mains input
Generator or main input
Always on
Always connected to the loads
By default, AC power is only available on AC output 2 if
external power is available on the Main or Gen input.
See section 6.2, AC transfer, to change the operation
preferences of AC output 2.
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