wise words Chris. just employing murphy`s law

But is the risk increasing?

I would say yes the risk is increasing because we are using more and more appliances that are susceptible.

Not many years ago most stuff was just simple current drawing items, telephone lines were the only things we had much local surge protection for. 

I am highly dubious about the merits of SPDs rated for 'domestic use'. Indeed, I haven't bothered with one for my own installation. Can't say I have ever experienced anything untoward as a consequence.

That is pretty much my attitude, but it could be different if I lived on the top of a hill with an aerial supply.

However, if you are going to install a new CU (either for yourself or in trade) is there any good reason for not including an SPD?

I live at the top of a hill but my supply is underground.

To answer your question - Yes I would, and have fitted them as a swap-out of an existing 3036 job, but I would never recommend a separate retro-fit to an existing installation.

In-CU or Out-CU I don't believe they are effective in either case, but Fusebox do em cheap enough to be a no brainer, and the best of all is that if they 'turn red' nobody will bother replacing them, nor will the customer notice any change in the characteristics of their supply!

whjohnson said:

best of all is that if they 'turn red' nobody will bother replacing them, nor will the customer notice any change in the characteristics of their supply!

That's very uncharitable! People will check them when they press their test buttons twice a year.

Oh of course they will - silly me!

I think that unless you have mission-critical kit, such as a server farm for a merchant bank, and can afford 'proper' SPD protection, then you are tiddling into the wind when it comes to domestic, especially when the things are constructed with dime store jelly bean priced components marked up 100s of percent. Still, it ticks another regs form box, and that seems to be all they are interested in these days.

I ask you - how many instances have there been whereby a house fire has been blamed on the electrics and the insurance company has refused to pay out on account of the cu being an old BS3036 rewirable with no RCD, no SPD and no AFDD present?

Personally, I've never heard of such an instance, and I don't believe there will ever be one. If the insurers went down that route, then no one other than mortgage holders would ever bother with house insurance again.

whjohnson said:

no one other than mortgage holders would ever bother with house insurance

Quite a few folk do not bother with insurance  as it is article in actuarial post suggests ~ 1/4 UK homes no content insurance and more like half for tenants though it is not clear from the articles I suspect the un-insured are those at the poorer end of the market, so les likely to have the all new fuseboard anyway.
Mike

More susceptible appliances or more appliances that generate voltage surges?