On the subject of pulling the DNO fuse.

Agreed - they overplay the danger thing to protect their market.. Having worked in an industry where HT switching and pulling 800A fuses was a daily thing, and yanking HRCs out of live 3 phase dist boards, the humble single phase domestic cut out holds no fears for me.

If I find a cast iron cut out, usually accompanied by a separate fused or linked neutral and both with pitch dripping out of them I steer well clear and get the customer to sort it directly with their supplier. THAT isn't worth the risk.

I can't understand why this is still up for discussion. You all know the answer to the question. Only the DNO and it's authorised contractors can pull the DNO's fuse. Full stop. If this isn't you - leave it alone. No if's, no but's. End of.


One reply to three posts...


To Arran Cameron's post - yes, I've seen an arc flash at a service termination and I'm very glad I wasn't kneeling in front of it. Superheated plasma, vaporised and molten metal being violently ejected at face level can cause life-changing injuries.


To Zoomup's post - it makes no difference if the cut-out's on-load or off-load, if there's deterioration inside, it's liable to go up. Bear in mind that deterioration may only come to light when the cut-out does explode in your face.


To whjohnson's post - we certainly don't overplay the danger. It's absolutely not about protecting markets. Safety is the number one priority. Arc flash can, and does, cause damage as well as horrific and life-changing injuries. "The humble single phase domestic cut out" is sealed for a reason, and if something went wrong while you were tampering with it, you'd have some very awkward questions to answer - assuming you'd been lucky enough to have escaped death or injury.


Service terminations present a fairly unique set of circumstances that exacerbate the consequences of something going wrong. They have no local protection. You can't switch it off. They're nearly always in an awkward corner of a confined cupboard, and to work on them you have to be up-close and personal. And you don't know what the history of that cut-out is. That cut out you're about to tamper with may have been submerged, it may have had impact damage from something falling on it, it may have been overloaded, it may even have been the subject of illegal interference. The old PILC service cable may be 70 years old and have no oil left in the papers. You just don't know. You may get away with it, but the consequences of not getting away with it are something you really don't want to contemplate.


I'm not overplaying this. I've been with a DNO all my working life (35 years) and there's not a chance in hell I'd pull a cut-out fuse outside of work - apart from the legal implications and the risk to my employment, I know the danger and it's just not something I'd gamble with.


Summary - You're qualified, you're experienced and you're competent, and that should answer the question (that you already know the answer to) - Don't interfere with the DNO's equipment. It's illegal and it's dangerous.

Howard,


Are you able to tell me how many non DNO electricians have been injured pulling fuses in the last 20 years ?

Are you able to explain why DNO's have operated various schemes throughout the years, including issuing stickers and seals to electricians to enable them to pull fuses, and still do ?

Are you able to explain why DNO's do not routinely fit isolators to their equipment to enable work to be carried out on installations ?

Hello Pat,


I seem to have opened a can of worms!


You've asked some good questions and have raised some good points.


To answer your first question, the answer's no! I can't tell you how many non-DNO staff have been injured pulling the DNO's fuse, I don't have access to that information (and probably never will), but you've raised a good and valid point - plus the tone of your question suggests that you don't think it's very many, and I agree with you - I don't suspect it's very many either.


It's the fact that it's illegal, and the potential consequences of it going wrong, that I'm trying to get across. I know you're all more than capable and more than competent, (and I know you've all done it), but what I'm saying is you'd be on a very sticky wicket if something went wrong. Whilst the odds of it going wrong are admittedly slim, it does happen, and when it happens it can really spoil your day. I've seen a service termination go up like a small bomb (ISCO single phase 60A metalclad on a 2c 04 PILC service), and if it had happened while somebody was working on it, that person would definitely have received burns, and would probably have been blinded. There were pellets of melted copper all over the opposite wall in the cupboard. Plus it took a 315A fuse in the substation a couple of streets away, plunging roughly one third of the customers on that feeder into darkness. So don't risk it please! 


To address your second point, I'm not aware of private electricians being issued with seals by the DNO - in my experience, I've never heard of this being done. Which DNO's do this? And do they operate any assessment or accreditation for it? I can only assume that if a DNO has issued an electrician with a set of sealing equipment, then that electrician has been assessed and recognised by the DNO as competent to work on their equipment, and as such can remove the fuse where necessary.


Re isolators being fitted (or not) - Prior to the late 80's, early 90's, the only isolation between the cut out and the customer's wiring was the main switch in the consumer unit. This had been standard practice since the year dot, rightly or wrongly. DNO's began installing isolators around the early 90's as standard on new supplies and service alterations, the top side (from the meter) being sealed with a wire seal, and a plastic seal on the customer side with a disclaimer notice attached. Then there was a period when meters were supplied with an integral isolator, being either of the traditional switch design or a rotary switch operated by a screwdriver. These meters had a split terminal cover, with the incoming supply side being wire-sealed. My personal opinion is that an isolator should be fitted as standard on all new supplies, and retrospectively at periodic meter changes. Would solve all kinds of problems and put these arguments to bed once and for all.


I do stand by my position on the legality and risk of interfering with DNO equipment, however for what it's worth - I think it's an insult to the intelligence of any registered electrician to have to call the DNO simply to pull a fuse, but that's the way the law stands, and whether you agree with it or not, that's what you're required to do. Bear in mind that I'm posting to this forum in my capacity as a DNO's SAP - and as such I have to uphold the regulations and safety rules. That doesn't mean I can't see your viewpoint - I can. Many years ago, as a 20-year old having just completed his apprenticeship, I felt a complete fraud having to pull a cut-out fuse for an electrician who'd been in the trade for over three times as long as I'd been alive. So I do see your points, and you have a perfectly valid argument, but I'm sorry, legally you can't do it!


That said, I'd reiterate the point I made in a previous post - I'm not aware of anybody having been pulled up or reprimanded for having removed the DNO's fuse in order to work safely. 


   

SSE policy on issueing temporary seals to agreed 3rd parties may be worth a read.

As an approach it seems very sensible and proportionate. Some key sections other DNOs could emulate, formalising what is and is not acceptable, and who is responsible.

Any qualified electrician will be permitted to remove a Company cutout fuse in the event of an emergency. Such an emergency would be deemed to be an overheating consumer unit.

3.2 Our Customer Service Centre (CSC) shall be contacted as soon as possible following disconnection and the reason for removing the cutout fuse stated. The appropriate depot will arrange to reseal the cutout within 7 days.

and also

Members of the following trade associations only are permitted to remove

security seals for routine work. The term Trade Association is used in the

remainder of this document and will apply to the following list of associations.

The National Inspection Council for Electrical Installation Contracting

(NICEIC)

The Electrical Contractors' Association (ECA)

 The Electrical Contractors' Association of Scotland (SELECT)

 National Association of Professional Inspectors and Testers (NAPIT).

 ELECSA (An ECA subsidiary)

In summary,  they will only issue named individuals with numbered temporary seals, in small numbers, on condition they are kept up to date of where they are being used. The individuals are only permitted to do this for single phase cut outs in good condition, and it is made clear that in all other than totally straightforward cases, the DNO should be called in.

 

Regarding isolators, I'd much rather have a good switch-disconnector than what amounts to a main switch from a domestic CU. I would also wish to be 100% sure that when I have locked it off, it stays locked off.


Regarding SSE's policy, I don't quite understand why a registered sparks can pull a fuse from a single phase head, but not a three phase one which is made up of three identical items. Perhaps it is because three phase ones may have a greater capacity than your ordinary 100 amp domestic ones. However, it's their equipment and their rules.

Not quite, 

the big sick bird - illegal,  means clearly prohibited by the law - a very clear example being  murder.
unlawful is "not authorized by law" , so you have no guaranteed right or permission to do this activity  enshirined in law.

An unlawful act may or may not also be illegal. An example is using someone else's land (that is not an official footpath) as an access, you have no legal right, but it is up to the land owner to decide if you have permission to cross it, or if they say trespassers will be prosecuted. Without permission, the action is not on its own criminal, but they may still sue in the civil courts. And if you also do something that is criminal while you are there, like commit theft  or criminal damage, then it does become illegal and a matter for the criminal justice system.

Opening someone else's fusebox is probably unlawful, but not illegal without other actions. Damage to the seals might be seen as criminal.


In general if something is illegal, there is always a law to point to that makes it so .

If it is unlawful there may not be anything in the statutes.