What about medical ? Emergency lighting, Alarms ?.
I can see that there is an argument for SPD on say, mains powered linked smoke alarms (and medical, alarms etc). But you are far more likely to have a power failure which renders smoke alarm system inoperable than you are a surge. So for the SPD requirement to make sense, a UPS needs to be mandated. Mission critical systems always have a UPS and just putting an SPD on is a waste. That of course will come in later iterations of the regs....but for now it ain't there !
 
I can see that there is an argument for SPD on say, mains powered linked smoke alarms (and medical, alarms etc). But you are far more likely to have a power failure which renders smoke alarm system inoperable than you are a surge. So for the SPD requirement to make sense, a UPS needs to be mandated. Mission critical systems always have a UPS and just putting an SPD on is a waste. That of course will come in later iterations of the regs....but for now it ain't there !

If you don't mind my asking - what edition of BS7671 are you referencing?

The problem for electricians is that, while many domestic installations may not benefit much from the addition of surge protection, its omission is no longer a matter that can be settled by a customer simply declining the option and now requires a risk assessment. A comprehensive risk assessment takes a significant amount of time, for which the designer will receive no compensation, whereas inclusion of surge protection adds minimal cost to an installation. If you were designing installations, would you take the time to write up a risk assessment for every individual, in many cases finding yourself unable to remove the requirement of surge protection, or would you include it as part of the specification and save yourself considerable hours of unpaid work?
 
If you don't mind my asking - what edition of BS7671 are you referencing?

The problem for electricians is that, while many domestic installations may not benefit much from the addition of surge protection, its omission is no longer a matter that can be settled by a customer simply declining the option and now requires a risk assessment. A comprehensive risk assessment takes a significant amount of time, for which the designer will receive no compensation, whereas inclusion of surge protection adds minimal cost to an installation. If you were designing installations, would you take the time to write up a risk assessment for every individual, in many cases finding yourself unable to remove the requirement of surge protection, or would you include it as part of the specification and save yourself considerable hours of unpaid work?
Such a risk assessment is super easy and super quick.
 
Such a risk assessment is super easy and super quick.

I can provide a risk assessment for anything within minutes, but producing one tailored to a particular installation that meets regulatory requirements and would stand up to legal scrutiny is another proposition entirely.

You didn't mention which edition of BS7671 you have referenced in previous comments.
 
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443.4.1 suggests options still exist, although limited.

It would be easy to take certain regulatory statements at face value and conclude that opinion of homeowner absolves designer of any responsibility, but 534.1 would also need to be considered and homeowner's thoughts on that are of no relevance.

GN1 also provides advice on this matter, but I don't have a current copy of it

I asked specifically what @slartybartfast was using as basis for their opinions as I suspect it is (now superseded) blue book.

I commissioned a board this evening in a newly rewired property and the homeowner expressed no opinion on fitment of SPD as I didn't ask for their thoughts on the matter. Difference in price between a main switch board and this main switch board with SPD (+ additional MCB) was £25+vat. If those few pounds had been a deal breaker, I suspect there were many other aspects of my quote that would have been more of a problem.
 
If, as should be done, a Hazard Analysis is carried out first and concludes that the Hazard does not exist or is of a very low consequence then a Risk Assessment does not have to be carried out.
 
I can see that there is an argument for SPD on say, mains powered linked smoke alarms (and medical, alarms etc). But you are far more likely to have a power failure which renders smoke alarm system inoperable than you are a surge. So for the SPD requirement to make sense, a UPS needs to be mandated. Mission critical systems always have a UPS and just putting an SPD on is a waste. That of course will come in later iterations of the regs....but for now it ain't there !
Placing a surge suppressor in front of the UPS isolates it and its connected equipment from major surge events. The IEEE Standard Section 9.11 states that networked SPD protection is needed and describes protecting a UPS with SPDs
 
If, as should be done, a Hazard Analysis is carried out first and concludes that the Hazard does not exist or is of a very low consequence then a Risk Assessment does not have to be carried out.
What's the difference between a Hazard analysis and a risk assessment when dealing with this scenario.
 
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I can see that there is an argument for SPD on say, mains powered linked smoke alarms (and medical, alarms etc). But you are far more likely to have a power failure which renders smoke alarm system inoperable than you are a surge. So for the SPD requirement to make sense, a UPS needs to be mandated. Mission critical systems always have a UPS and just putting an SPD on is a waste. That of course will come in later iterations of the regs....but for now it ain't there !
There is no argument it's a requirement.

And even if the owner declares that surge protection isn't required, then the equipment still has to comply with the rated impulse voltage.
And would need to check that the data, signal, and telecom lines require protection to preserve lighting protection Zones LPZ concept 443.1.1, 534.1
 
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What's the difference between a Hazard analysis and a risk assessment when dealing with this scenario.
They are two entirely different things in the scheme of Health and Safety, a Hazard analysis is always done first and then a risk assessment if necessary, it not always the case that the hazard has to be managed, the difference between the two are often miss-understood.
 
They are two entirely different things in the scheme of Health and Safety, a Hazard analysis is always done first and then a risk assessment if necessary, it not always the case that the hazard has to be managed, the difference between the two are often miss-understood.
An electrical hazard analysis identifies dangers that are present in an electrical system.

Mike Johnson said:
If, as should be done, a Hazard Analysis is carried out first and concludes that the Hazard does not exist or is of a very low consequence, then a Risk Assessment does not have to be carried out.


Are you saying that if there are no electrical hazards, then a risk assessment for fitting an SPD is not required ?
 
The first order of business in any H&S protocol is to eliminate the Hazard, If there is no hazards then a risk assessment is not required.
 
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The first order of business in any H&S protocol is to eliminate the Hazard, If there is no hazards then a risk assessment is not required.

But you can't eliminate the chance of voltage surges, so a risk assessment is the thing to do.
 
There is no allowance for a risk assessment for the installation of SPDs anymore.

True, but I think most of this discussion has been around the previous guidelines/regs.
 
There is no allowance for a risk assessment for the installation of SPDs anymore.
The AQ criteria (conditions of external influence for lightning) for determining if protection against transient overvoltages is needed are no longer included in BS 7671. Instead, protection against transient overvoltages has to be provided where the consequence caused by overvoltage (see Regulation 443.4)

(a) results in serious injury to, or loss of, human life, or
(b) results in interruption of public services/or damage to and cultural heritage, or
(c) results in interruption of commercial or industrial activity, or
(d) affects a large number of co-located individuals.

For all other cases, a risk assessment has to be performed in order to determine if protection against transient overvoltage is required.
 
The AQ criteria (conditions of external influence for lightning) for determining if protection against transient overvoltages is needed are no longer included in BS 7671. Instead, protection against transient overvoltages has to be provided where the consequence caused by overvoltage (see Regulation 443.4)

(a) results in serious injury to, or loss of, human life, or
(b) results in interruption of public services/or damage to and cultural heritage, or
(c) results in interruption of commercial or industrial activity, or
(d) affects a large number of co-located individuals.

For all other cases, a risk assessment has to be performed in order to determine if protection against transient overvoltage is required.
You appear to be quoting the previous version of BS7671 here.

This is an extract from Amendment 2:

443.4 Overvoltage control

443.4.1 Transient overvoitages due to the effects of indirect lightning strokes


Protection against transient overvoltages shall be provided where the consequence
caused by the overvoltage could result in:

(i) serious injury to, or loss of, human life
(ii) failure of a safety service, as defined in Part 2
(iii) significant financial or data loss.

For all other cases, protection against transient overvoltages shall be provided unless the owner of the installation declares it is not required due to any loss or damage being tolerable and they accept the risk of damage to equipment and any consequential loss.
 
You appear to be quoting the previous version of BS7671 here.

This is an extract from Amendment 2:

443.4 Overvoltage control

443.4.1 Transient overvoitages due to the effects of indirect lightning strokes


Protection against transient overvoltages shall be provided where the consequence
caused by the overvoltage could result in:

(i) serious injury to, or loss of, human life
(ii) failure of a safety service, as defined in Part 2
(iii) significant financial or data loss.

For all other cases, protection against transient overvoltages shall be provided unless the owner of the installation declares it is not required due to any loss or damage being tolerable and they accept the risk of damage to equipment and any consequential loss.
Try chapter 44 Protection against voltage disturbances and electromagnetic disturbances.
 
True, but I think most of this discussion has been around the previous guidelines/regs.
I just skimmed the whole thread again, and you're correct, it dates back to before Amendment 2.
However, in the context of whether an SPD should have been fitted to an EV charge point, the previous version states that if a risk assessment is not carried out (and documented), then an SPD shall be fitted.

So the installer had no real reason not to fit one, unless they produced a documented risk assessment.
 

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