Surge Protection Devices for domestic - what do you think?

[a-z electrics]

Evening all,
Just attended elex exeter and see there's a big push on these SPDs coming as standard now in domestic consumer units. Hager, Lewden and Contactum to name just 3.
I have had at least 2 clients in the last few months whose appliances have been damaged by apparently surges on the supply when power has been lost/switched back on, one was an ASHP and the other an Aga oven controller.
Disregarding what it says in the Green book, the additional cost of these when fitting/changing a board is not that great and they appear easy to fit retrospectively if there's a spare way for one. or even in a separate enclosure so I personally think there's a case for recommending them to customers..
What do people think, anyone else had any experiences?

 

[buzzlightyear]

Just attended elex exeter and see there's a big push on these SPDs coming as standard now in domestic consumer units. Hager, Lewden and Contactum to name just 3.
I have had at least 2 clients in the last few months whose appliances have been damaged by apparently surges on the supply when power has been lost/switched back on, one was an ASHP and the other an Aga oven controller.
Disregarding what it says in the Green book, the additional cost of these when fitting/changing a board is not that great and they appear easy to fit retrospectively if there's a spare way for one. or even in a separate enclosure so I personally think there's a case for recommending them to customers..
What do people think, anyone else had any experiences?

Disregarding what it says in the Green book, blue now read what it says .

 

[suffolkspark]

How do we fit these in boards on TT.... they need to be installed upstream of RCDs as far as i can make out.... Which makes sense... But on a TT if using dual rcd boards there will be a 100ma typeS right upfront....

 

[Ian1981]

How do we fit these in boards on TT.... they need to be installed upstream of RCDs as far as i can make out.... Which makes sense... But on a TT if using dual rcd boards there will be a 100ma typeS right upfront....

They can be installed downstream of an rcd for TT installations as long as the upstream rcd is an S type with an immunity to surge currents of at least 3 Ka

 

[a-z electrics]

Disregarding what it says in the Green book, blue now read what it says .

Yes blue book too.. but I was asking for experiences if any. Do you have any?

 

[rolyberkin]

The last one I fitted was in a SBS board and cost the customer £30, bit of a no brainer really, fit it and forget it. IMHO if they don't want to pay the £30 then they have to raise it as an issue and sign a disclaimer, I know that most domestic properties do not need them but when the cost is so low why not.

 

[Wilko]

Hi - Control boards do fail, but I think its most likely due to the board design and components. I'm careful to follow a power down process for boilers, for example. I can only hope SPD will increase their survival rate in general use. My last 2 CU changes have included SPD at Customer request after I explained possible benefits. These were Wylex flex boards and it added a lot more than £30 to the material cost.

 

[a-z electrics]

The last one I fitted was in a SBS board and cost the customer £30, bit of a no brainer really, fit it and forget it. IMHO if they don't want to pay the £30 then they have to raise it as an issue and sign a disclaimer, I know that most domestic properties do not need them but when the cost is so low why not.

SBS board? never heard of them, where do you get those from?

 

[Deleted member 9648]

We just discuss with the client at the quote stage, if they decline surge protection then it is stated on the EIC that the client declined, nobody has to sign a disclaimer.

 

[Carl S]

SBS Trade Sales - the home of bespoke distribution boards - Order - https://www.sbstradesales.co.uk/order/

 

[buzzlightyear]

I use those boards company known has live ,if I can not use CED gear .

 

[Old Tiler 19727]

The last one I fitted was in a SBS board and cost the customer £30, bit of a no brainer really, fit it and forget it. IMHO if they don't want to pay the £30 then they have to raise it as an issue and sign a disclaimer, I know that most domestic properties do not need them but when the cost is so low why not.

What about TT fed with overhead lines? We're meant to fit a type 1 and those don't cost £30. I do a a fair few TT installs and I've only had one customer agree to the additional £££££ for the type 1.

TT, in my opinion, isn't well served by the main manufacturers, especially in regard to DP RCBOs. It's pointless having an up-front 100mA S-type protecting the distribution board/cable if an uncleared N-E fault downstream is going to take out the whole installation. CP Fusebox seem to be about the only manufacturer doing reasonably priced DP RCBOs, but they still lack a reasonably priced type 1 SPD as far as I can tell.

 

[loz2754]

Why a type 1?
I was taught this is only required if there is a lightning protection system installed.
(3 year old thread btw)

 

[nicebutdim]

I think type I is recommended for TT systems fed by overhead lines.

 

[pc1966]

CP Fusebox seem to be about the only manufacturer doing reasonably priced DP RCBOs, but they still lack a reasonably priced type 1 SPD as far as I can tell.

The Wylex/Crabtree compact RCBO are also neutral-switching and not too expensive. They do (or did...) a type 1+2 SPD as well.

As above, it is not the 'TT' aspect that merits a type 1 SPD but those systems on long overhead lines which are likely to pick up a lot more energy in the event a pole is hit, etc. They are often TT, but might also be TN-C-S depending on how the DNO thinks about the supply earth arrangements.

 

[pc1966]

As a general point, type 1 (or 1+2 which are more useful) SPD are always going to be far more expensive than type 2 due to the larger devices needed to absorb the energy. Typically the energy of the "standard" direct strike waveform (10us/350us) is an order of magnitude larger than the standard induced strike (8us/20us) waveform for a given peak current. Also within type 1 SPD you get different protection levels based on energy, and of course a cost for the beefier ones.

But there are 3rd party SPD manufacturers you can use as they typically are cabled in and not busbar mounted. For example:

SY12325KA2P - Type 1+2+3, 25ka, single phase, with window indication - Surge Devices

Lightning protection Level 3, 25kA 10/350μs. Fully compliant to BSEN62305, BS61643-11 & BS7671. Combined arrester Type 1+2+3 can handle direct lightning strikes and protect sensitive electronic equipment. Suitable for all installation types (TT, TNC-S & TN-S). Low let through voltage <1.3kV...

www.surgedevices.co.uk

Not cheap, but less eye-watering than most!

As a final point you will see some SPD describes as suitable for TT or for TN, that is kind of determined by the arrangement of protective devices with the usual TT configuration having a MOV from L-N, and a GDT from N-E. Realistically they are fine for most TN systems as well (as above example is described).