UK Is an SPD required for a loft conversion?

[ionionascu]

Hi. We live in an older house and we are doing a loft conversion. We do not have an SPD on the connection to the grid and the builder's electricians insist that we must have one, otherwise he can't sign the certificate, but he doesn't want to give me a reason. We have a few consumer units under the stairs, next to the meter and I do not think there is enough space for him to do any changes now. I want to have an SPD installed, but not right now as we plan to do some other changes in the house soon and I do not think it is worth paying for something now just to have it changed in a few months. Can someone please tell me whether there is a legal requirement to install an SPD when doing a loft conversion? (the house is a semi-detached with a looped connection and the electrician didn't even have to connect a new loop to the consumer unit as this had alreay been done a few years ago when we had some other electrical work done in the house). Thank you

 

[pc1966]

I've seen one with red flags on 2 of 3 phases. Who knows how long it had been like that? Mad that I've also seen them in new industrial installations with no link to BMS.

Indeed, most of the better quality SPD have the switch for an indicator but rarely used. We did, using the wonders of diodes and the diode-action of the LED indicators, to have 3 'fail' lights and one 'good' light that was logical AND of the status:

The SPD on the left is the 'DB' one, there are others at the incoming points for mains and for backup generator.

 

[Mike Johnson]

The three phase surge protector I had on my board in France had separate plug in modules for each phase after replacing them for I think the third time at a not inconsiderable cost, I removed them and just remembered to switch everything off when a storm approached, once had the living room lit up by a lightning ball travelling through the house most interesting.

 

[pc1966]

The three phase surge protector I had on my board in France had separate plug in modules for each phase after replacing them for I think the third time at a not inconsiderable cost, I removed them and just remembered to switch everything off when a storm approached, once had the living room lit up by a lightning ball travelling through the house most interesting.

Clearly not rated for the job!

Fit Type 1 SPD if you have a rural site / overhead line / high lightning incidence situation.

 

[Mike Johnson]

Probably right, when I installed the SPD about ten years ago, I knew nothing about them, not much has changed since then.

 

[nicebutdim]

Indeed, most of the better quality SPD have the switch for an indicator but rarely used. We did, using the wonders of diodes and the diode-action of the LED indicators, to have 3 'fail' lights and one 'good' light that was logical AND of the status:
View attachment 109777

The SPD on the left is the 'DB' one, there are others at the incoming points for mains and for backup generator.

I'm guessing someone pokes their head in that room on a regular basis. Imagine high value processes being protected by an SPD which remains locked away in a switch room where no one might check its status for weeks on end. Power won't ever be interrupted, but SPD could be taken out today and equipment by a later surge and no one would understand what went wrong. Everything in buildings monitored to within an inch of its existence, yet this fairly critical piece of kit gets overlooked. The odds of two surges are probably remote, but linking surge protection back to BMS would be a relatively trivial cost.

 

[mainline]

Clearly not rated for the job!

Fit Type 1 SPD if you have a rural site / overhead line / high lightning incidence situation.

If you are in a rural environment it’s most likely to be TT earthing so more than likely neither would a type 1 spd.

 

[mainline]

I'm playing devils advocate, what I was trying to say is, if you don't have a surge protector then your TV will break, possibly because of a surge (unlikely but possible) but probably because its made of crap. If you do have an SPD fitted your TV will still break because its made of crap, no surge protector will stop that, but you are down £250.

Surely the most sensible thing to do with £250 is buy some sort of insurance policy that protects electronic stuff against damage.

And how come this wasn't a problem a few years ago, metal oxide varistors have been around since adam was a lad, there was never any need to fit them 10 years ago to anything. Are TV sales going to fall off a cliff now we are getting surge protectors, if that was true the tory mates that own big electronic business would never allow them.

A high percentage of fails in modern stuff is usually down to the use of smps power supplies.
A decent spd can only help to iron out the incoming supply and increase the chances of its survival.

 

[mainline]

Doesn't most of the electronic stuff have surge protection built in anyway, a lot of the stuff Big Clive takes to bits has those blue MOV inside already. and of course stuff has a built in expiry time, even the original humble light bulb

Bird rental video recorders had a time fuse in

If you don’t want to fit spd,s then don’t fit them.

 

[davesparks]

And how come this wasn't a problem a few years ago, metal oxide varistors have been around since adam was a lad, there was never any need to fit them 10 years ago to anything.

There was a real-world need for them 10 years ago, and even longer ago than that. The need for them has been increasing as the amount of sensitive electronics in the world increases.

 

[MJPD29]

I've seen one with red flags on 2 of 3 phases. Who knows how long it had been like that? Mad that I've also seen them in new industrial installations with no link to BMS.

I’ve never seen one activated. After some sites I’ve seen recently that have suffered from lighting strikes I’m starting to wonder how useful some of them are.

 

[davesparks]

I’ve never seen one activated. After some sites I’ve seen recently that have suffered from lighting strikes I’m starting to wonder how useful some of them are.

Very useful if, like most things, the correct devices are installed properly. They are far less useful if not.

SPDs dont protect against direct lightning strikes, but should be installed as part of a properly designed lightning protection system.

 

[nicebutdim]

I’ve never seen one activated. After some sites I’ve seen recently that have suffered from lighting strikes I’m starting to wonder how useful some of them are.

Only happened to notice in passing and figured I should bring it to the attention of someone from the company. For the life of me I can't remember where this was as it wasn't somewhere I work regularly. I do remember thinking it had probably been like that for some time and remember it mostly as only two phases had taken the hit.

 

[oscar21]

There was a real-world need for them 10 years ago, and even longer ago than that. The need for them has been increasing as the amount of sensitive electronics in the world increases.

But we did have them though, I remember sockets even in the 90's that had big removeable cartridges that needed changing when they showed red. I occasionally saw them where things like cash registers were plugged in in shops.

I always thought they were a snake oil product sold by the shop fitting firm frightening the owners into thinking they would loose all their money if the till broke, despite it being full of notes.

 

[Mike Johnson]

The only thing the lightning strike took out was the Orange Router, replaced by Orange free, so far cheaper than replacing the SPD cartridges.

 

[Risteard]

Doesn't most of the electronic stuff have surge protection built in anyway, a lot of the stuff Big Clive takes to bits has those blue MOV inside already. and of course stuff has a built in expiry time, even the original humble light bulb

Surge protection needs to be cascaded to be effective. Simply having a Type 3 surge arrester in the equipment may not provide any real-world protection as the magnitude of the surge may simply be too great for it.