MultiPlus-II 120V

On delivery, the inverter/charger is set to standard factory values. These settings are generally suitable for single-unit operation.

Settings that are not self-explanatory are described briefly below. For further information, please refer to the help files in the software configuration programs. See the Configuring chapter.

Inverter frequency

Output frequency if no AC is present at the input.

This setting is not adjustable; it is permanently set to 60Hz.

Input frequency range

Input frequency range accepted by the MultiPlus-II. The MultiPlus-II synchronises within this range with the AC input frequency. The output frequency is then equal to the input frequency.

Adjustability: 50, 60 or 45 – 65 Hz.

Input voltage range

Voltage range accepted by the MultiPlus-II. The MultiPlus-II synchronises within this range with the AC input. The output voltage is then equal to the input voltage.

The solution is to increase the lower limit setting to 110VAC (the output of AVR generators is generally very stable), or to disconnect the inverter/charger from the generator when a generator stop signal is given (with the help of an AC contactor installed in series with the generator).

Inverter voltage

Output voltage of the MultiPlus-II in battery operation.

Adjustability: 110 - 130V

Stand-alone / parallel operation / 2-phase / 3-phase setting

Using several devices, it is possible to:

The standard product settings are for standalone operation. For parallel, three-phase or split-phase operation, see the Configuring chapter.

AES (Automatic Economy Switch)

If this setting is turned ‘on’, the power consumption in no-load operation and with low loads is decreased by approximately 20%, by slightly 'narrowing' the sinusoidal voltage. Applicable in stand-alone configuration only.

Search Mode

Instead of the AES mode, the search mode can also be chosen. If search mode is ‘on’, the power consumption in no-load operation is decreased by approximately 70%. In this mode the MultiPlus-II, when operating in inverter mode, is switched off in case of no load or very low load, and switches on every two seconds for a short period. If the output current exceeds a set level, the inverter will continue to operate. If not, the inverter will shut down again.

The Search Mode ‘shut down’ and ‘remain on’ load levels can be set with VEConfigure.

The standard settings are:

Shut down: 40 Watt (linear load)

Turn on: 100 Watt (linear load)

Ground relay (see appendix B)

With this relay, the neutral conductor of the AC output is grounded to the chassis when the AC input relays are open. This ensures the correct operation of earth leakage circuit breakers in the AC output.

For specific configurations, such as a split-phase system with an autotransformer, an external ground relay may be necessary. To use an external relay, first, disable the internal ground relay in the MultiPlus settings. For the location of the external ground relay contacts, see Appendix A.

Battery charge algorithm

The standard setting is ‘Four-stage adaptive with BatterySafe mode’. See Section 2 for a description.

This is the recommended charge algorithm for lead acid batteries. See the help files in the software configuration programs for other features.

Battery type

The standard setting is the most suitable for Victron Gel Deep Discharge, Gel Exide A200, and tubular plate stationary batteries (OPzS).

This setting can also be used for many other batteries: e.g. Victron AGM Deep Discharge and other AGM batteries, and many types of flat-plate flooded batteries.

With VEConfigure the charge algorithm can be adjusted to charge any battery type (Nickel Cadmium batteries, Lithium-ion batteries).

Absorption time

In case of the standard-setting ‘Four-stage adaptive with BatterySafe mode’ the absortion time depends on the bulk time (adaptive charge curve), so that the battery is optimally charged.

Automatic equalisation charging

This setting is intended for flooded tubular plate traction or OPzS batteries. During the absorption stage, the voltage limit increases to 2.83V/cell (34V for a 24V battery and 68V for a 48V battery) once the charge current has dropped to less than 10% of the set maximum current.

Not adjustable with DIP switches.

See ’tubular plate traction battery charge curve’ in VEConfigure.

Storage voltage, Repeated Absorption Time, Absorption Repeat Interval

See Section 2.

Bulk Protection

When this setting is ‘on’, the bulk charging time is limited to 10 hours. A longer charging time could indicate a system error (e.g. a battery cell short-circuit).

AC input current limit

These are the current limit settings for which PowerControl and PowerAssist come into operation:

Factory setting: maximum grid in-line topology value.

UPS feature

If this setting is ‘on’ and AC on the input fails, the MultiPlus-II switches to inverter operation practically without interruption.

The output voltage of some small generator sets is too unstable and distorted for using this setting – the MultiPlus-II would continually switch to inverter operation. For this reason, the setting can be turned off. The MultiPlus-II will then respond less quickly to AC input voltage deviations. The switchover time to inverter operation is consequently slightly longer, but most equipment (most computers, clocks or household equipment) is not adversely impacted.

Recommendation: Turn the UPS feature off if the MultiPlus-II fails to synchronise, or continually switches back to inverter operation.

Dynamic current limiter

Intended for generators, the AC voltage being generated by means of a static inverter (so-called ‘inverter’ generators). In these generators, engine rpm is reduced in case of low load: this reduces noise, fuel consumption and pollution. A disadvantage is that the output voltage will drop severely or even completely fail in the event of a sudden load increase. More load can only be supplied after the engine is up to speed.

If this setting is ‘on’, the MultiPlus-II will start supplying extra power at a low generator output level and gradually allow the generator to supply more, until the set current limit is reached. This allows the generator engine to get up to speed.

This setting is also often used for ‘classical’ generators that respond slowly to sudden load variation.

Weak AC

Strong distortion of the input voltage can result in the charger hardly operating or not operating at all. If WeakAC is set, the charger will also accept a strongly distorted voltage, at the cost of greater distortion of the input current.

Recommendation: Turn WeakAC on if the charger is hardly charging or not charging at all (which is quite rare!). Also turn on the dynamic current limiter simultaneously, and reduce the maximum charging current to prevent overloading the generator if necessary.

BoostFactor

Change this setting only after consulting with Victron Energy or with an engineer trained by Victron Energy!

Programmable relay

The relay can be programmed for all kinds of other applications, for example as a starter relay for a generator.

Auxiliary AC output (AC-out-2)

Intended for non-critical loads and directly connected to the AC input. With current measurement circuit to enable PowerAssist.

The following hardware is required: