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Anyone seen this before
- Thread starter jelliottelectrical
- Start date
Provide your own fuse!
Two immediate possibilities come to mind:
1.... Maybe suggest that they go away and learn some Physics? They really ought to understand that if one installed an additional fuse (of credible/practical rating) it would be impossible to guarantee that it would NOT be THEIR fuse which operated first (hence "protecting ONE'S cables") in the event of excessive current flowing in ONE'S cable - so that if they really wanted to be sure that a fuse of theirs would never find itself protecting one's cables, they would need to replace it with a very fat nail
.2... Tell them that what they say is fine - since you do not wish your cables to have any such 'protection'.
As I said, I've fitted 80A fuses not far from 'right next' to their 60A ones
I wonder what they would say about that, given that my 80A fuses are fine for protecting my cables, yet it's quite possible that their 60A ones would blow first? 
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1. Yes, one could do that. And they could either change their rules after such a challenge, or they could say "Do you want to connect to our network or not?".Two immediate possibilities come to mind:
1.... Maybe suggest that they go away and learn some Physics? They really ought to understand that if one installed an additional fuse (of credible/practical rating) it would be impossible to guarantee that it would NOT be THEIR fuse which operated first (hence "protecting ONE'S cables") in the event of excessive current flowing in ONE'S cable - so that if they really wanted to be sure that a fuse of theirs would never find itself protecting one's cables, they would need to replace it with a very fat nail
2... Tell them that what they say is fine - since you do not wish your cables to have any such 'protection'.
2. Yes - there are probably all sorts of ways in which one could contravene the regulations if one didn't like what they said. Would that one be a C1, C2, or C3?
They could - but I'm far from convinced that, in practice, they would.
I presume you're talking about an EICR? If so, why would it be 'coded' at all? If one's meter tails were adequately protected by a fuse (which happened to be the DNO's fuse), would that not be fine as far as an EICR was concerned, regardless of any silly statement from the DNO that their fuse 'could not be used' for that purpose (when it was actually doing just that)?
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Who knows what they would in practice do. I take issue (great issue) with all those who flatly refuse to accept that they are entitled to insist on a fuse or that such an insistence is laughably unjustifiable and can therefore be completely ignored.
From LV Customer Supplies Up To 100A Document Number: EDS 08-2101 (with a bit of highlighting)
5.6 Customer Cables (Meter Tails)
The following cables shall be provided by the customer for connection to the meter by the
supplier appointed meter operator:
• BS 7671 25mm2 copper PVC/PVC insulated conductors from the meter to the cut-out.
• BS 7671 25mm2 copper PVC/PVC insulated conductors from the meter to the customer
ownership boundary.
If the distance between the cut-out and the consumer unit is greater than 3 metres an
additional point of overcurrent protection (e.g. switch fuse etc.) shall be installed to ensure
adequate protection of the meter tails is afforded². However, it is recommended that an
additional point of isolation is always provided to allow independent operation of the customer
installation without recourse to UK Power Networks
² BS 7671 (regulation 434.3) states that a device for protection against fault current may be omitted if the DNO
agrees that the protection at the origin of the installation (cut-out fuse) affords protection up to the main distribution
point and that the wiring between the origin and main distribution point is carried out in such way as to reduce the
risk of a fault to a minimum. As per BS 7671 (regulation 434.2.1), UK Power Networks considers a distance not
exceeding 3m (between the cut-out and main distribution board) sufficient to minimise the risk of a fault or damage
occurring.
It seems pretty clear from what UKPN say that the regulations require their agreement for their fuse to be used.
From https://niceic.com/newsletter/omission-of-overload-protection/ :
In general, a device for overload protection is required at the point where a reduction occurs in the current carrying capacity of the conductors of the installation. However, except where a location presents a risk of fire or explosion, overload protection need not be provided:
- Where the Distributor agrees that their overload device(s) provide(s) overload protection between the origin and the main distribution point of the installation (so long as overload protection is provided at that point) (433.3.1).
It seems pretty clear from what NICEIC say that the regulations require the distributors agreement for their fuse to be used.
So an electrician encountering a contravention of the regulations has a choice:
C1/C2/C3 or taking the view that the DNO are being very silly indeed and he's just going to ignore what they say and pretend that the contravention isn't happening.
Which would you suggest he does, given that he is a professional and being paid to produce a professional report on the condition of the installation wrt its compliance with the the regulations?
That surely makes no sense? An upstream fuse of appropriate rating to provide adequate protection against overcurrent for a cable of a given CSA (and installation method) provides that protection regardless of its length. Hence, if the DNO fuse is adequate to protect a cable (of given CSA and installation method) which is less than 3m in length, it's surely adequate to protect that cable if it is longer than 3m, isn't it?
Yes, it does say that but, as above, why on earth would (should) a DNO not agree that that their fuse provides adequate fault protection IF their (upstream) fuse is of an appropriate rating to provide adequate protection for the cable concerned?
It does, indeed, also say that but, again, it makes no real sense to me. The whole point of having a protective device is in case, despite attempts to minimise the risk (which, hopefully one does in any situation), a fault does occur? One could surely say that any cable should be installed "such as to reduce the risk of a fault to a minimum" (and, in no other context would one suggest that an upstream protective device only provided protection for a short length of cable).
That seems to be an 'abuse' of 434.2.1 - which says that 'downstream' fault protection is acceptable under certain circumstances if the protective device is no more than 3m from the origin of the cable (or point at which CSA reduces). We are talking about a DNO fuse which is upstream of the entire length of the tails concerned.
NICEIC have views about all sorts of things, but not necessarily views with which everyone agrees. They have no 'authority', except, in some senses, over their members.
An EICR is surely not required to consider compliance (or otherwise) with DNO conditions/statements, is it? If an EICR inspector is satisfied that there is an upstream fuse providing adequate overcurrent protection to the meter tails (per Physics, electrical principles and BS 7671 general requirements for overcurrent protection), is that not 'satisfactory'.
It would seem (at least to me) rather bizarre to suggest that, say, 25mm tails protected by an 80A or 100A fuse was "potentially dangerous, requiring urgent remedial action"! Even (to my mind) "Improvement recommended" would be stretching things!
See above.
Interesting meter tail stuff. i've been having a look at some documents. My DNO is SSEN. The supply agreement has no mention of any length restriction. But some other documents do. eg the Service alterations guide
mentions it twice
and (very interesting)
Note, this specifies an isolator SWITCH, no mention of a fuse!
mentions it twice
and (very interesting)
Note, this specifies an isolator SWITCH, no mention of a fuse!
I am sorry you do not seem to understand the situation.
Perhaps I am being petulant (why is it only me who is petulant?) because you will not answer the question.
How do you prevent it doing so?
Of course. Eureka!
I would remove the DNO fuse and insert another.
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Good grief - you really have jumped onto EFLImpudences hands-over-the-eyes, fingers-in-the-ears, can't-see-or-hear-anything-I-don't-want-to bandwagon, haven't you.
But in the meantime, back in the real world, if they do not agree then, as you say, the wiring regulations are clear that their fuse may not be the one categorised as protecting the cables, and therefore not providing one which can be is a contravention.
And it doesn't matter one iota if you, EFLImpudence, or any electrician doing an inspection don't see why they should have to, or don't see any possible justification for them ever not doing so. Unless you think we should be in the situation where people can legitimately just ignore regulations which they think are silly, the fact remains that the wiring regulations say what they say.
Physics, electrical principles and BS 7671 general requirements for overcurrent protection are irrelevant if the owner of the fuse does not give his agreement for it to be used in a particular context and the wiring regulations explicitly mandate that he must if it is to be used in a particular context.
That doesn't matter if the DNO don't give permission to use their fuse, and the wiring regulations say you must have it.
It doesn't matter why they would not agree, except in the context of lobbying them to change their rules.
But in the meantime, back in the real world, if they do not agree then, as you say, the wiring regulations are clear that their fuse may not be the one categorised as protecting the cables, and therefore not providing one which can be is a contravention.
That doesn't matter in the context of whether you have the authority to disregard DNO rules and wiring regulations.
I'd not be surprised if that was a general requirement.
So nowhere else in the regulations is there a relationship between cable length and the type of protective device? OK.
Who is abusing any regulation by quoting it if it explicitly says that DNO agreement is required?
That's the whole point. The cables are more than 3m long AND THE FUSE IS NOT THE PROPERTY OF THE OWNER OF THE ELECTRICAL INSTALLATION AND THEREFORE HE MAY NOT USE IT HOWEVER HE CHOOSES JUST LIKE HE MAY NOT CHANGE IT TO A DIFFERENT VALUE.
If you have a copy of the regulations please scan and upload the regulation in question to show that NICEIC have misquoted it. Same for the quote that UKPN gave.
No, but unless UKPN and NICIEC have falsified quotes it is an actual wiring regulation which states that the DNO have to agree for their fuse to be used.
And it doesn't matter one iota if you, EFLImpudence, or any electrician doing an inspection don't see why they should have to, or don't see any possible justification for them ever not doing so. Unless you think we should be in the situation where people can legitimately just ignore regulations which they think are silly, the fact remains that the wiring regulations say what they say.
It seems I need to remind you that, unless the quotes are falsified, there is an explicit requirement for DNO agreement in the regulations.
Physics, electrical principles and BS 7671 general requirements for overcurrent protection are irrelevant if the owner of the fuse does not give his agreement for it to be used in a particular context and the wiring regulations explicitly mandate that he must if it is to be used in a particular context.
It would seem to me that unless those regulation quotes have been falsified there is no alternative to saying that if the owner of the fuse denies you the right to use it then you have no fuse at all from a regulatory compliance POV.
I don't believe you, but I haven't got time to respond to your 'sentence-by-sentence' responses to what I wrote at the moment. I'll try to find time to respond a bit more later.
You repeatedly write that/it "doesn't matter". However, I was saying nothing about whether or not things 'mattered' but, rather, was indicating the things that appeared (to me) to make no real sense, in terms of physics/electrical principles. It is for others to decide' whether it 'matters' if DNOs create rules which make little/no sense.
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