I wouldn't go so far as C2.

443.4.1 is interesting. If injury or loss of life, then clearly a non-compliance, so C3. Much the same applies to a safety service because it might lead to injury or loss of life. However, define "significant" in indent (iii). A significant financial loss to you might be loose change to me, or vice versa.

"For all other cases" seems to make non-compliance optional. That said, it would seem prudent to make an observation.

As to Stuart's second question, all I can say is that I have fitted SPD to my new distribution board at home. I didn't really see the need, but I felt that I should. We have been here for almost 26 years and nothing has been damaged yet due to an over voltage.

I completely agree with the above. The requlation does not specify when the spd should be fitted.

I would always note the lack of SPD but it would be a C3 at he absolute most.

I would always fit with a new fuseboard but i have only recently heard a few saying they fit with any new circuit. I cant see any requirement for this in the regulations.

The requlation does not specify when the spd should be fitted.

I agree the regs don't say "when". They do seem to cover "what" should be protected though - i.e. unless the 'owner says they don't want it & accept the risk', that's everything covered by the current version of BS 7671. So that would seem to imply that all additions should be provided with SPD protection (unless the owner opts out) no matter how small or large.

So it feels a bit like when RCD protction for sockets was introduced - even one extra socket on an existing ring would have to be provided with 30mA RCD protection, even if the rest of the ring could remained as it was. Could be done locally (RCD socket or RCD FCU), per-circuit with an additional RCCB in its own enclosure, change the MCB to an RCBO, complete consumer unit change, or up-front RCCB before the consumer unit. The customer pays their money and takes their choice.

    - Andy.

Just to be clear then.

An SPD should be fitted with any new circuit?

Stuart said:

Just to be clear then.

An SPD should be fitted with any new circuit?

You can't make that assumption I'm afraid. No "one size fits all" rule. Fitting SPDs into an existing installation requires some knowledge and decision making that isn't really covered by BS 7671.

For example, if the building has a lightning protection system LPS), but no SPDs. BS 7671 requires BS EN 62305 to be followed. At this point, it's over to a specialist company, if you are not yourself experienced with BS EN 52305 series.

The worst possible case is a building with existing LPS to the now withdrawn BS 6651 - it would perhaps be wrong to simply fit an SPD in this case, as the whole premises would have to be re-evaluated against BS EN 62305 series.

Just to be clear then.

An SPD should be fitted with any new circuit?

I'd suggest that SPDs need to be considered for any addition (be that a new item on existing circuit, new circuit, CU change or new installation) - although the consideration might will finish with 'the customer doesn't think it would be worth the additional cost' (which is maybe quite likely for small, low risk, additions).

i should probably add that there's probably less scope for just plonking an individual SPD at the start of an addition (like we might have been able to do with RCDs) - as there needs to be some co-ordination with other things, including likes of main bonding (the boiler PCB isn't going to be protected much by an SPD at the start of a new spur, as the PCB's "earth" could be dragged back down by main bonding and the gas supply pipe).

   - Andy,

It is worth being clear on the premises.  A dwelling vs a non-dwelling.  Very few dwelling have a lightning protection system LPS but a commercial or industrial building might.

Lets say in a domestic dwelling an average 3 bed semi.

SPD cost might be £30 to £100

Points to Consider

Space in CU/DB

CU/DB type.  Could be an old Wylex Bakelite with rewirable fuses

Space around the CU/DB if SPD will be an external unit

In this day and age I personally feel that every dwelling should have an SPD fitted if it is a new install/build or if wiring alterartion are done.  The average home has a lot more electronics in it than a home from 30 years ago.  There are 3 types of SPD 1, 2, 3.

Type 1 is normally used in LPS

Type 2 is normally put in the CU/DB

Type 3 is normally at the connection to the appliance.

A lot of manufacturers now are doing a combined type 2 & 3 for the CU/DB.  The rule of thumb is that it cascade down from 1 to 3.  1 being able to deal with more punishment than 3.

There had been situations or discussions in the past few years about people needing a mains power smoke alarm and the designer saying it will need an SPD fitted which in turm meant a new CU/DB.  Then cost becomes a major factor.

If an SPD gets fitted then the customer needs to be made aware they are meant to periodically check the flag on the SPD to see if this is still in good order.  Customers will do whatever after that.  In a rental property either private or social an EICR will be performed which will hopefully pick on the state of the SPD.  Woth noting most EICR are done every 5 years as people are currently only paying lip service to the correct way which is

Every 5 years or CHANGE of tanancy.  (Some EICR retest dates are shorter than 5 year on the engineering dicretion of the electrician or the nature of the building or buisiness)

gkenyon said:

You can't make that assumption I'm afraid. No "one size fits all" rule. Fitting SPDs into an existing installation requires some knowledge and decision making that isn't really covered by BS 7671.

It may even not be possible. The CU may be full, and even if it is not, there may be no SPDs available that could go in there. There may be space constraints which do not allow a separate enclosure to be close enough.

Perfect! "I am afraid that you will need a new CU, Madam." ;-)

Thanks guys. These are all excellent responses.

The issue i have is that we work for a large housing association with roughly 25,000 properties.

We EICR all properties every 5 years so roughly 5000 a year. All of our DBs have RCBO's fitted on every circuit but no SPDs. If we are changing the fuseboard we would always fit a new board with an SPD however the issue is with the need for an SPD on a new circuit or addition. We did not think that was required.

You can fit the SPD in an external enclosure next to the CU/DB if required.  Caveat in the length of the cable.  Parts A, B and C of the Total cable length should be ideally 50cm or less. 

Have a look at www.surgedevices.co.ukPDF

The PDF may also help

Hi Stuart

It is also worth checking the smoke alarms, Carbon monoxide alarms and heat alarms when doing an EICR.  Functional test and the expiry date if they have one. 

Aico do some good free CPD on this and also some paid for courses.

Hi Stuart

It is also worth checking the smoke alarms, Carbon monoxide alarms and heat alarms when doing an EICR.  Functional test and the expiry date if they have one. 

Aico do some good free CPD on this and also some paid for courses.