question

fancourt avatar image
fancourt asked

Inverter RS Smart/Smart Solar (non-PV) AC battery charging via AC-out?

Hi everyone,

Have searched but can't find if anyone has asked this before...

First - a lot of the discussion on here about these RS inverters involves confusion between the "Inverter RS Smart/Smart Solar" and the "Multi RS Solar"...

I am talking about the former (without an AC-in), not the latter (with an AC-in).

According to the relevant manuals, both the "Inverter RS Smart/Smart Solar" and the "Multi RS Solar" are capable of supporting 100A battery charging via AC-coupled PV connected on their AC-out.

My question is this:

Is there any reason (DNO regulations notwithstanding) why this AC-coupled PV battery charging feature could not be (mis)used to enable mains (or generator) AC charging of the connected battery, provided that:

a) any AC-coupled PV was first disconnected from the system and
b) a mechanism was implemented to disconnect the mains/generator AC _BEFORE_ the Inverter RS attempts frequency-shift control at the point where the battery reaches the programmed absorption voltage?

This question is mainly to enhance my understanding of these products rather than for system design purposes. It would however be useful to know if this was an option as a temporary/emergency solution (generator rather than grid).

Obviously for a system design requiring mains AC battery charging the Multi RS Solar is the correct product choice.

Many thanks!

inverter rs
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1 Answer
Guy Stewart (Victron Community Manager) avatar image
Guy Stewart (Victron Community Manager) answered ·

Hi @fancourt,

It is not possible to connect a sine wave forming source (such as the grid or a generator) to the AC output of either models.

It is only possible to connect a sine wave synchronising inverter to the AC output.

The AC input of the Multi RS will synchronise the AC output of the Multi RS to the sine wave that is generated by the grid or generator, that is why it is able to be used in this way.

The Inverter RS which does NOT have an AC input connection will not synchronise, and attempting to connect a different (unsynchronised) sine wave to the AC output will result in damage to either the inverter or the generator (most likely depending on which is stronger), or both.

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fancourt avatar image fancourt commented ·

Thanks @Guy Stewart (Victron Community Manager) !

That makes perfect sense now I think about it more... of course it's the GTI in an AC-coupled arrangement that synchronises to the Victron inverter output, not the other way around... thanks again for clearing that up for me.

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