Is this type of install now outside of this PAS?

Batteries are not within a common fire rated enclosure with Overcurrent protection… or are they? 

Martyn said:

Batteries are not within a common fire rated enclosure with Overcurrent protection… or are they? 

If I remember correctly 'non-combustible enclosure containing the overcurrent protection' (6.1.1 of the PAS). They certainly seem to be metal enclosures ... I don't know whether those batteries have internal overcurrent protection (but if not, I can't see any overcurrent protection on the DC side from the pictures, and we probably need to consider that for BS 7671). I'm also not sure whether they have accessible "push to disconnect" terminals either (see 4.2.1 of the PAS).

Whether they need fire resisting separation, if there is no option but to install indoors, is discussed in 6.5.1 of the PAS (i.e. making sure locations in 6.5.5 are not compromised).

Evening Graham, 

I wonder if I can pick you brains on this a little more…

There are some notable exclusions in the PAS and I wondered what the reasoning for limitation was…

Domestic dwellings exceeding 200 m2 in floor area.

200m2 seems to be quite a low threshold, a fairly typical 3 bed semi can surpass this ?

It suggests at 6.5.5 (g) that batteries must not be installed in lofts etc  However PCE equipment is permitted in lofts. - do we assume the risk mitigation here is chemical rather than weight?

In Table 4 it lists BS EN IEC 62281 as the standard for Lithium, which is a transport standard…

On checking my ‘usual’ product they claim compliance to these two IEC standards amongst a few other EMC/UL/UN

IEC 63056:2020 

Secondary cells and batteries containing alkaline or other non-acid electrolytes - Safety requirements for secondary lithium cells and batteries for use in electrical energy storage systems

IEC 62619:2022 

Secondary cells and batteries containing alkaline or other non-acid electrolytes - Safety requirements for secondary lithium cells and batteries, for use in industrial applications

Neither of these seem to get a mention in the PAS at all…

The standards listed for ‘enclosures’ also dont seem to line up with anything from the likes of Eldon (Nvent Hoffmann) IEC 62208 for example

It’s a tough reed, I usually feel fairly confident with standards and interpretation etc but this seems to have reference after reference to standards, that when checked, dont seem to match up and fairly common industry standards seem absent…

Thanks

Martyn

Hi Martyn,

There was a public consultation, which was widely publicised including in this Forum: RE: Public Consultation: PAS 63100 Electrical installations – Protection against fire of battery energy storage systems for use in dwellings – Specification 

I'll cover the battery standards first. This is (to me at least) interesting and will perhaps cause some debate (apologies for that, but here goes ...).

• BS EN 63056 makes reference to batteries conforming to BS EN 62619
  
• BS EN 62619 as you point out covers industrial lithium batteries.
• Reg 511.1 of BS 7671 states: 'Every item of equipment shall comply with the relevant requirements of the applicable British or Harmonized Standard, appropriate to the intended use of the equipment.'
• Reg 511.2 states 'Where equipment to be used is not covered by a British or Harmonized Standard or is to be used outside the scope of its standard, the designer or other person responsible for specifying the installation shall confirm that the equipment provides at least the same degree of safety as that afforded by compliance with BS 7671. Such use shall be recorded on the appropriate electrical certification specified in Part 6.'

Quite simply, the lack of a standard for domestic lithium batteries causes their selection to be a "non-standard approach" as far as BS 7671 is concerned. Some more standardization work is needed here ... whether that's development of a domestic battery standard, or a way of making it possible to recognize industrial lithium batteries used outside the industrial sector is of course open to question.

Similarly, if you are quoting UL or other standards not aligned with IEC standards, Reg 511.2 again effectively requires some form of statement from the designer or installer as to the safety being "no less safe than BS 7671".

Perhaps less controversial is enclosures. The standards for battery assemblies/installations in 6.2.1 of PAS 63100 are not those simply of the "enclosure", but cover installation or assembly of "batteries in enclosures". The ones quoted are assembly or installation standards for batteries in enclosures (or in the case of BS EN IEC 62485 series, in commercial/industrial situations this could also be a battery room). This would not preclude the use of BS EN 62208 enclosures ... but it would be up tot he designer of the installation to check ventilation and protection requirements in selecting an appropriate enclosure. Referencing particular BS EN IEC 62485 series is not new ... it's been referenced in the IET CoP for EESS for some time (perhaps overlooked?). BS EN IEC 62485-5 had not been published when the 2nd Edition was finalized, but I am quite certain we will see that standard referenced in the 3rd Edition which will be available very soon.

Martyn said:

There are some notable exclusions in the PAS and I wondered what the reasoning for limitation was…

Domestic dwellings exceeding 200 m2 in floor area.

200m2 seems to be quite a low threshold, a fairly typical 3 bed semi can surpass this ?

Larger premises may require more power, but also are likely to have more space to dedicate to batteries, including perhaps outdoors etc.
There are limits in 6.5.7 that may otherwise be problematic.  In future, as we learn from more implementations, I can see the standard developing.

Martyn said:

It suggests at 6.5.5 (g) that batteries must not be installed in lofts etc  However PCE equipment is permitted in lofts. - do we assume the risk mitigation here is chemical rather than weight?

A bit of both. Interesting to consider that the battery can be a victim of a fire as well as a potential cause, so whilst weight (and perhaps the way monoblocs are seen placed hapazardly in lofts), added to chemical, and the fact that lofts have different compartmentation etc., all go in the mix.


Hope this is useful ... please keep providing feedback as it will help standards develop as we use them.

I havent followed the forum in a while so was blindsided by this news as it hasnt been widely publicised.

Im quite shocked at the level of restriction placed on battery storage systems given the incidence rate of fires within properties.

Where does this leave previously installed systems. The introduction of this British Standard is clearly going to influence insurers and so existing installtions may have to be updated. Is their guidance on this?

About 50% of our installs have been outside. I like them (apart from the worry about rodent damage to cabling).

However, that leaves 50% that cant be easily located outside. Mostly terraced houses. 
From what ive read, the changes for ESS require:

1) any indoors located battery systems (in non 6.5.5 locations) to have open air ventilation. Is this dedicated or a trickle vent?

2) fire detection systems upgraded to LD2 throughout the property. Fire detection to be upgraded if necessary and signed off to standards of 5839-6. LD2 not to be confused with the basic LD3 standard of escape routes only.**

**Note this requirement applies to inverters sited in lofts. Again is this retrospective? 

David

Martyn said:

200m2 seems to be quite a low threshold, a fairly typical 3 bed semi can surpass this ?

Not nowadays. New builds in my area are tiny - around 30 m² per bedroom.

gkenyon said:

A bit of both. Interesting to consider that the battery can be a victim of a fire as well as a potential cause, so whilst weight (and perhaps the way monoblocs are seen placed hapazardly in lofts), added to chemical, and the fact that lofts have different compartmentation etc., all go in the mix.

A fair point. For me, the most obvious site would be in a walk-in attic storage space immediately below the panels. That seems to be ruled out, but not an adjacent storage room, which gives access to the loft.

I do not quite understand the 200 m² limit to the scope - the loft space of a larger house is unlikely to be any safer than one of a small house.

On a more practical note, does it matter electrically where the battery is sited please? (I had thought that it would make sense to keep all the DC bits together.)

Consider a fire in a loft, origin or cause are not important at the moment.  Now add an inverter or battery or both.

PIR insulation is optional (most are a Petrochemical derived Polystrean with is flammable)

The fire could spread from one building to the next quite easy across the roof structure especially in a terrace house or semi.

Now you have 2 fires to deal with.  


Most lofts were designed in old houses just to keep the ceiling up,  there design was not to carry weight.  There are further considerations,
Battery unit coming through the ceiling onto people below, this could be during a fire or due to the weight.
Chemical leaking out of battery unit on a failure or during a fire


Home battery technology needs to improve.  We need a BS EN to define a battery pack/unit for a dwelling.  They could also be made self extinguishing.  I have seem some with this capability already.

There was a public consultation, which was widely publicised including in this Forum: RE: Public Consultation: PAS 63100 Electrical installations – Protection against fire of battery energy storage systems for use in dwellings – Specification 

Also, on LinkedIn and other platforms: www.linkedin.com/.../ghkenyon_public-consultation-pas-63100-electrical-activity-7081315104314531841-5roQ

Where does this leave previously installed systems. The introduction of this British Standard is clearly going to influence insurers and so existing installtions may have to be updated. Is their guidance on this?

Probably a similar situation to whenever a standard is "improved" over time - e.g. installations with 5s disconnection times on final circuits using BS 3036 fuses, missing 30mA RCD protection to indoor sockets, or even red & black insulation (BS 7671) or having solid metal pins on 13A plugs (BS 1363). The powers that be tend to be pragmatic, especially if the alternative is refusing customer's money (e.g. insurance companies might be more likely to up the premiums a little if an actual problem is perceived rather than refuse cover). Mostly the new version of the standard gets used (after a while) for new installations, but existing ones carry on pretty much as before (if with the occasional C3 on an EICR that gets mostly overlooked).

I do note that a PAS (a Publicly Accessible Specification) isn't quite in the same stable as a true British Standard (like BS 7671) - I suspect it'll more likely be taken notice of by system (and component) manufacturers - and then be used as a selling point. At present at least there's no reference to PAS 63100 in BS 7671 for instance - so it won't directly feed into EICRs (although the conscientious might flag it up - like the lack of a thermal cut-out on immersion heaters).

  - Andy.