2. Description
2.1. Boats, vehicles and other stand-alone applications
The basis of the MultiPlus-II is an extremely powerful sine inverter, battery charger and transfer switch in a compact casing.
Important features:
Automatic and uninterruptible switching
In the event of a supply failure or when the generating set is switched off, the MultiPlus-II will switch over to inverter operation and
take over the supply of the connected devices. This is done so quickly that operation of computers and other electronic devices is
not disturbed (Uninterruptible Power Supply or UPS functionality). This makes the MultiPlus-II highly suitable as an emergency
power system in industrial and telecommunication applications.
Two AC outputs
Besides the usual uninterruptable output (AC-out-1), an auxiliary output (AC-out-2) is available that disconnects its load in the
event of battery operation. Example: an electric boiler that is allowed to operate only if the genset is running or shore power is
available. There are several applications for AC-out-2.
Please enter “AC-out-2” in the search box on our website and find the latest information about other applications.
Three phase capability
Three units can be configured for three-phase output. Up to 6 sets of three units can be parallel connected.
PowerControl – maximum use of limited AC power
The MultiPlus-II can supply a huge charging current. This implies heavy loading of the AC mains or generator. Therefore a
maximum current can be set. The MultiPlus-II then takes other power users into account, and only uses “surplus' current for
charging purposes.
PowerAssist – Extended use of generator or shore current: the MultiPlus-II “co-supply” feature
This feature takes the principle of PowerControl to a further dimension allowing the MultiPlus-II to supplement the capacity of the
alternative source. Where peak power is often required only for a limited period, the MultiPlus-II will make sure that insufficient AC
mains or generator power is immediately compensated for by power from the battery. When the load reduces, the spare power is
used to recharge the battery.
Programmable relay
The MultiPlus-II is equipped with a programmable relay. The relay can be programmed for different applications, for example as a
starter relay for a generator.
External current transformer (optional)
External current transformer option to implement PowerControl and PowerAssist with external current sensing.
Programmable analog/digital input/output ports (Aux in 1 and Aux in 2, see appendix)
The MultiPlus-II is equipped with 2 analog/digital input/output ports.
These ports can be used for several purposes. One application is communication with the BMS of a lithium-ion battery.
2.2. On-grid and off-grid systems combined with PV
External current transformer (optional)
When used in a grid-parallel topology the internal current transformer cannot measure the current to or from the mains. In this
case an external current transformer has to be used. See appendix.
Frequency shift
When solar inverters are connected to the output of a MultiPlus-II, excess solar energy is used to recharge the batteries. Once
the absorption voltage is reached, charge current will reduce and excess energy will be fed back into the mains. If the mains is
not available, the MultiPlus-II will slightly increase the AC frequency to reduce the output of the solar inverter.
Built-in Battery Monitor
The ideal solution when the MultiPlus-II is part of a hybrid system (diesel generator, inverter/chargers, storage battery, and
alternative energy). The built-in battery monitor can be set to start and stop the generator:
- Start at a preset % discharge level, and/or
- start (with a preset delay) at a preset battery voltage, and/or
- start (with a preset delay) at a preset load level.
MultiPlus-II 48V 3kVA 120V
Page 2
Description
