Yikes, blown the suppy company neutral fuse ...

There I was tonight in this super newly installed electric shower (oh, and gas - but that's for another tale) and using it for the first time.

10.5kW, 44Amps or thereabouts. Wired via an RCD and spliced into the existing meter tails to the existing consumer unit. My thoughts are on how great this mains pressure shower actually is.

Then the lights went out. Silence.

Great :(

Call for SWMBO. Nothing. She'd left the house to potter in the garden shed. I'm wet, covered in soap suds, can't see a thing, where is the blinkin torch...

Ah, the meter ain't displaying. We've blown the supplier main fuse. All other fuses, trips and RCDs fine.

The guy from the emergency electrical service sorts it out, and we are back on again. However, our supplier fuses are old - probably 50 or 60 years - and from his comments look to be wired with 30 amp fuse wire. That said, the shower overload has taken out both the live and neutral fuse wires. He whistles though his teeth, sez "neutral, that is weird" and trundles off with a promise to be back tomorrow to uprate the fuses to a more consumer friendly 100 amps.

I can't see anything strange in the neutral fuse expiring, it has been on duty for ages - and the overload of our new shower has shown it the cards. So why is this guy whistling through his teeth?

Is tomorrow going to be a likely sales opportunity for his company?

Reply to
Adrian C
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Is it because neutrals are not fused now - in case a neutral only blows it could leave the circuits live.

Reply to
John

There shouldn't be a neutral fuse by the standards of the past decades, which is why he was surprised.

If it that ancient, they might well replace the cutout completely now or real soon. At the very least, it's almost certain he'll replace the neutral fuse with a solid link at least for now and replace the live fuse.

Another issue is what the cutout is actually rated at - you can't bung a

100A fuse in any ancient old crap. But a 60A supply fuse should cope OK with a shower plus reasonable other loads unless you spend an hour in the shower while running the leccy cooker and fan heaters flat out. As a very general rule of thumb, a typical fuse in this class (and there are a few classes of cutout fuse) will take around 30 mins to blow at double it's rated load, ie 120A for a 60A fuse so you can get away with a bit.
Reply to
Tim Watts

I suspect that is what will happen.

And no sales talk at all

Reply to
ARWadsworth

I find the distribution people (the ones who actually install and maintain the supply rather than the ones to whom you pay your bill) (Mine's CE, formerly NEDL (nee NEEB)) are usually down-to-earth (no pun intended) engineers rather than sales-orientated types.

Normally the neutral "fuse" nowadays is bypassed with a solid bar to avoid the whole system becoming live if a neutral fuse should rupture rather than the line one.

Reply to
Frank Erskine

I've not met a neutral "board" fuse, but I remember my Grandmother had a metal-clad fuse-box with a fuse in the live and neutral of each circuit.

I think its installation had a lot to do with equipment shortages during the war. Incidentally all the sockets were those Wylex ones with in-line pins.

Reply to
Graham.

The fact that there is a neutral fuse in there at all I would guess! It ideally wants to not be there at all, or at least be linked out with a substantial bit of copper.

Reply to
John Rumm

When I did something similar (worked on a socket while live to avoid disturbing SWMBO while she was watching Tarnation Street) I didn't get billed because the fuse was 60A in a 4 bed house.

Derek

Reply to
Derek Geldard

There was aprogramme within the Supply Industry to remove all rewireable fuses back in the 1970's - 80's from memory. Needless to say not all were replaced, although managers were declaring in returns that they were. The replacement will be at their expense.

Reply to
The Wanderer

Friend of mine moved house last year. Their 1920s house (in an area that was one of the last DC supply areas in the country) still had two fuses, and electrics to match. This wasn't even picked up on the survey.

I have a neutral fuse here, although it's on a supply that was removed in 2000. Some other equipment adjacent to it is '80s dated though, and no-one thought to remove the neutral fuse at the time. I think it was installed on a 1950s AC overhead supply.

If a neutral fuse fails, you're well rid of it.

Reply to
Andy Dingley

Amen to that! Western Power Distribution in my case.

I have a billing problem at present. "Good Energy" are trying to bill me =A31500, for =A3120 of electricity I've already paid for, through a supply that has been disconnected for 10 years, when I'm not even a Good Energy customer. The only people who've been at all helpful in resolving this have been WPD, even though billing is the one part of it that isn't even their problem.

Reply to
Andy Dingley

Interestingly, in large parts of continental Europe, it is standard to have both live and neutral fuses, and there is no discrimination at the sockets between live and neutral, together with random variation from socket to socket as to whether it offers an earth. From my trips to Norway, I have looked at their standard domestic electrical setup and shuddered. Cartridge fuses in both live and neutral at the consumer unit, unshuttered sockets with mixed live and neutral - and two pin plugs that can be inserted either way round. And they wonder why they have so many electrically-caused house fires.

Oh, and ring circuits are unheard of.

Sid

Reply to
Sidney Endon-Lee

If you've already taken the route of two-pin connections and relying on insulation more than an earthed case, then there's less need to avoid the fused neutral. You have however lost the benefits of metal cases being earthed, for protection against internal shorts to that case.

Reply to
Andy Dingley

Thinking back to my pole mounted transformer, which I think had a neutral fuse, its actually not really clear which is live and which is neutral.

You CREATED a neutral by driving a stake into the ground, and connecting one side of the supply to it. I am not sure which side of the fuse that was.

I can envisage a situation where someone shorts the live side to earth upstream of the fuse..then maybe a neutral side fuse makes sense.

Anyway, glad its all gone now.

Reply to
The Natural Philosopher

That sounds like my setup here in the US... two modern breaker panels, load control relays, four ancient fuse boxes (mixture of barrel and screw- in fuses), a big knife switch for the well pump, a plethora of wall socket types (some grounded, some not), and a mixture of modern wire and old cloth-covered stuff. Most of it's 110V, some of it's 220.

cheers

Jules

Reply to
Jules Richardson

Oh, I'm afraid there have, and still are. They should have gone long since, but there are still lots around.

I used to work for the

So did I.

Someone would have removed equipment like that

You'd think so.

Reply to
The Wanderer

Nope, never.

Depends whether it's a two wire, split phase, or three phase transformer.

Rubbish. Consumer earth rods have nothing to do with earthing the incoming supply neutral.

The supply company *always* earthed their system to create a neutral. That went back as far as the 1922 Electricity Supply Regulations, now superceded by the Electricity Safety, Quality and Continuity Regulations 2002. Oh, and that goes for hv and ehv systems as well.

Unfortunately what you envisage makes no sense, given that the neutral must always remain intact since the introduction of PME. Neutral Inversion, OTOH, can be a problem, particularly in rural areas, but that requires two or three things to have gone wrong, both with a customer's installation and the supply network.

Please don't try spouting on matters about which you have not the first idea.

Reply to
The Wanderer

Maybe it's the same reason so many fires are blamed on "electrical faults" here...

I have read that Norway uses 230v three-phase supplies, with no neutral, so single-phase appliances are connected between two phases, therefore both wires are live.

Ring circuits and fused plugs were introduced in the UK to save copper etc. in the post-WW2 rebuilding programme, they have a number of disadvantages.

Reply to
alexander.keys1

This is 'Class 0' protection, which has not been permitted in the UK for many years, and is now on the way out on the Continent, it relies on there being no extraneous conductive parts and an insulating floor to limit shock current, even there it was prohibited in conductive locations such as concrete floors, kitchens, bathrooms, cellars etc.

Reply to
alexander.keys1

Probably the biggest disadvantage of early ring circuits was that a lot of leccies didn't really understand them, and took each end of the ring to a separate fuse. If one fuse blew for any reason the whole (non) ring was then fed from one fuse, albeit probably only 15A (unless they'd doubled the 15A fuse wire in the carrier).

Reply to
Frank Erskine

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