KH-10 PV lightning / Surge protection (Inverter Hardware Versions?)

[Sparky72]

Dear All,
The good news is that my installation is booked in for September !

I was going through various post-quote paperwork, and noticed my installer does not habitually install PV side lightning protection (Or PV array grounding for that matter)
I quiried this, as MCS state equipment must be installed as per manufacturers instructions.
(I should point out that this is a medium sized, roof mounted domestic installation)

I had already read the KH user manual, and recalled it was very explicit - 3/4 of a page doom and gloom - about fitting lightning protection:

Manual V1.2 (10-500-10073-02)
..........2.3 Surge Protection Devices (SPDs) for PV Installation
..........WARNING!
..........Over-voltage protection with surge arresters should be provided when the PV power system is installed.
..........The grid connected inverter is not fitted with SPDs in both PV input side and mains side.
..............etc.

My installer thought the situation was different,

And I've found there is a newer manual, with a drastically different take on it:
Section 2.3 has been truncated to just 3-lines!

Manual V1.4 (10-500-10073-04)
..........2.3 Surge Protection Devices (SPDs) for PV Installation
..........WARNING!
..........Over-voltage protection with surge arresters should be provided when the PV power system is installed.
..........The storage inverters are equipped with SPDs on the PV input side as standard, in order to meet the
..........secondary lightning protection requirements.

They don't state what they mean by "Surge arresters" and how these are differernt to the internal SPDs!
From a technical point of view, SPDs ARE "Surge arresters"


These two manuals are clearly contradictory.
And given the version numbers and content, the earlier one isn't likely to be a typo, it was a statement of fact at the time.
It really suggests there *was* no transient protection on the PV input at all.

We don't typically protect our TVs and Satellite dishes from a lightning strike, and damage if proven could probably be claimed on a UK buildings & contents policy.
So I'm not so miuch concerned about a direct lightning strike.
But I am concerned if there is no transient protection on older models, and if external MOVs / SPDs are mandatory in every case.

So,
Has there been a hardware change I should look out for on delivered equipment?
Are external SPDs mandatory? and if so, what are they suggesting?
I cannot work out what date these manuals were released.
I'm still waiting for service.uk@fox to get back to me...

Regards.



PS... Thanks for the previous feedback regading K-Series string 3300w power limits.
I found the reference at the very end of youtube "FoxESS Product/Community Q&A - 7th June 2024"
But I could not find any other question about the limit in this forum - what other forum has this limit been discussed on?

PPS... Yes I'm an engineer (30yr+ electronic design engineer) - so I do tend to read the small print !

[Dave Foster]

In all honesty the advice I have always been given (and followed) is that the inverters do not need additional dc protection but you do need SPD's fitted on the AC incoming feed.

So I'd be very interested to hear what Foxess come back to you with on this point - as i'm not aware of any changes being made in the KH series hardware.

If you are a facebook user there is a much more active forum there (and that's the one referred to) - you can find that here https://www.facebook.com/groups/foxessownersgroup to be honest even if you're not a Facebook user it's worth signing up for that as there's so much historical information on there.