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johnparvic asked

Earth connect for island mode with BSS?

I'm looking at a primarily self consumption setup with 4kW grid connected PV, 4.8kW DC connected PV and 14 - 20kWh battery storage with provision for a generator, so the Quattro looks like the best option at present. The property is TN-C-S (PME).

The latest UK wiring regulations require the distributors earth to be connected to the islanded system neutral (N-E bond) during island mode,

See https://electrical.theiet.org/wiring-matters/years/2021/84-march-2021/island-mode-earthing-arrangements-new-guidance-in-the-second-edition-of-the-iet-code-of-practice-on-electrical-energy-storage-systems/

for details. Figure 3 shows a relay for the N-E bond on the maintained loads side.

In grid connected mode the island mode isolator is closed and the N-E bond relay is open. In island mode the island mode isolator is open and the N-E bond relay is closed. There's a break before make timing sequence to follow.

How is this supported in ESS?

Many thanks

Kind regards

John

ESS
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4 Answers
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wkirby answered ·

The backfeed relays (both live conductors for single phase) and N-E bonding relay are are contained within the Quattro and operate as required depending upon the presence of AC at the inputs. The timings would be governed by the grid requirements (UK G98 / G99). Earth bond relay closes as soon as the backfeed relays have opened to prevent two earth bond positions.
Which brings me on to the next point. Only the Quattro 8kVA, 10kVA and 15kVA have certificates and these are G99 because of their size.
The MultiPlus 3kVA and 5kVA have a G98 certificate, but only one AC input.
Certificates here: https://www.victronenergy.com/support-and-downloads/certificates

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Jay avatar image Jay commented ·

Noobie here so please excuse me if I've misunderstood something. I own a Quattro 24/8000 and purchased specifically to use for ESS in the UK. I've found there's a blanket G100 conformance declaration but the document is hosted on a retailer's site: https://midsummerwholesale.co.uk/pdfs/victron-g100-declaration-multi.pdf

The Quattro 8kVA is listed as awaiting for testing at the ENA register but only the 48V model. The 24V version is not submitted for testing. Does this mean owners of 24v version will not be allowed to utilise this on the UK grid?

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johnparvic answered ·

Excellent - super clear answer, and yes the Quattro 8 or 10 kVA looks like the product for me.

Many thanks

Kind regards

John

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johnparvic avatar image
johnparvic answered ·

One supplemental question - do you know when the ENA are likely to issue their G99 cert for the Quattro? On their website it says "Awaiting assessment" - I'm guessing this is a result of Brexit and should be a formality.

Many thanks

Kind regards

John

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wkirby avatar image wkirby ♦♦ commented ·
It very much depends upon how many cups of tea the ENA are required to drink before contemplating testing the device. I would imagine that more cups of tea will be needed during the contemplation process. Once the tea urn is empty then they might have nothing else to do except conduct some assessments.
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johnparvic answered ·

LOL!

I know exactly what you mean - having worked with them in a previous life!

Many thanks

Kind regards

John

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