MultiCompacts improved: faster switching to grid

The hardware in our MultiCompact inverter/charger range has been improved: it can now switch much faster from inverter mode to mains mode. Combined with our high peak power ratings, this makes it possible to switch to mains mode before shutting down in an inverter overload alarm. This is especially useful in Self-consumption Hub-1 and 2 installations: it allows using an inverter/charger with a nameplate power below the system power.

The old hardware will take approximately 8.5 seconds to switch from inverter- to charger-mode, the new hardware can do it within half a second. Some notes:

• single phase installations will be even faster than the half a second mentioned;
• fast switching is only possible in the 3xx firmware versions. The difference between 3xx on one hand, and 1xx and 2xx on the other hand is approximately another 0.5 second in the worst case scenario: slightly differing frequency, and inverter being 180 degrees out of sync with the grid;
• all larger models, 3kVA and upwards, already have fast-switching since a long time;
• do not forget the other limit to using an ‘undersized’ Multi Compact in an installation: the AC transfer capacity. Max system load may never exceed the transfer switch capacity;
• the load-shedding functions in the self-consumption hub-1 and 2 Assistants give options to further undersize a Multi Compact: use an external relay which is controlled via the Auxiliary output;
• mentioned switching delays have not been measured exactly;
• for parallel and three-phase operation, please check the Disqus comments below.

Lots of little details, but all together the conclusion is that this significantly reduces the chance of a Victron switching off in overload condition.

Availability

Because of stock and production logistics, it will be a while before all different models are shipping with the new hardware. Below table gives an overview of the current situation, from our main warehouse DSV in the Netherlands.

The column serial shows from which serial number onwards this change has been implemented. And the column Shipping @ DSV shows if the new version is already being shipped from DSV.

If you require a model that is not yet shipping as such from DSV, this is possible at an extra cost of EUR 50,= per unit.

Table last updated 20 november 2014

Matthijs Vader