FoxESS Community - Owners & Installers Forum

Hi all,

It seems the H3 Pro 30kW has an EPS output for keeping the loads powered in the event of a mains outage.
Why is would an EPS Box Pro be needed?

Is it correct to assume that when in "offgrid" mode, the EPS Box Pro would only be able to provide 25A per phase ?
And is it correct to assume that when in "offgrid" mode, the H3 Pro 30kW would be able to provide 45.5A per phase ?

Finally the H3 Pro does the switch in under 10ms from grid into backup power ?
And the EPS Box Pro would take about 3 seconds ?

So in all cases there is no actual advantage between the EPS box pro compared to the H3 pro ?

The EPS output is simply an output that the inverter will divert power to in the event of grid failure.

This is often used in isolation as a critical power supply in the home for when the grid fails, but there can be potential issues around earthing when the grid is isolated and so the subject of EPS connections is a complex one.

The EPS Box Pro is a complete changeover unit that sits between your house and the inverter / grid and it will automatically changeover the house loads to the EPS output should the main grid fail, it allows local earthing arrangements to be fitted making the house safe to run entirely on EPS when the grid fails.

I'm more curious as to how it works in terms of "backup" power, as well as backup switching time.

An H3 Pro 30Kw inverter is able to support 45.5A per phase in <10ms ?
An EPS Box Pro is able to support 25A per phase in < 3s ?

So what would be the case not to support the whole house directly from the Inverter (Apart from the earthing issues)?

It seems to also changeover to EPS output, support at lease the same load or even more, and be quicker in changing.
Also, am I right to assume with the EPS Box, that every PV power generated over the 25A would then be sold to the grid instead of used by the house loads?