Post by Goodsparks on May 7th, 2009, 8:10pm
Quote:
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Yep.... Some of us sad people would.....
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DIY Forum >> Electrical Questions >> Rewireable fuses https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1241475737 Message started by kamog on May 4th, 2009, 11:22pm |
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Title: Rewireable fuses Post by kamog on May 4th, 2009, 11:22pm Do rewireable fuses have to be replaced under latest regs? I have old Wylex consumer unit, still in 'as new' condition. I am told one can get plug in rcds which take the place of the old fuse which would be so easy to do but is there anything I should be aware of in changing fuse to rcd? |
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Title: Re: Rewireable fuses Post by The_Trician on May 5th, 2009, 12:16am You can't get plug-in RCDs - you CAN get plug-in MCBs. You could fit a RCD in a stand-alone enclosure and protect the whole consumer unit with that. Another thing to look out for, is that fitting a RCD can highlight faults that were previously masked by the use of just fuses, especially if any DIY add-ons have been made anywhere in the house. Having proudly fitted your new RCD, you might well find that it won't set, or reset because a rewirable fuse won't pick up an existing earth fault. As far as the regs go, the set-up you describe won't pass the new regs, but if you leave it alone it would most likely have passed earlier regs. Welcome to the money-spinning world of how to make money for the electrical equipment manufacturers by constantly changing the wring regulations. You see, had the IET Wiring Regs Committee - of whom comprises members from the UK Electrical Equipment Manufacturers, left the wiring regs to sensible chaps instead of Euro-Bureaucrats and crooks, we'd all still be safe with BS3036 rewirable fuses, or we may even have had a sensible breather for a while and just added a requirement for MCBs, but then again the kit makers would have most likely gone bust by now. Instead, it has now been decreed that 'It don't Pass unless it's got a RCD. Never mind that we now have to trust people's lives with a piece of kit which is not 100% fail-safe, but hey - they gotta make money! 'Innovation & Constant Tinkering With The Regs' is their Mantra. Rant over TT |
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Title: Re: Rewireable fuses Post by kamog on May 5th, 2009, 6:20am Alas you'll think I am an idiot but I typed 'rcd' when I meant to put 'mcb' I do know the difference in function but initials sometimes confuse me. As it happens there already is a separate rcd serving the consumer unit I enquired about. |
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Title: Re: Rewireable fuses Post by Lectrician on May 5th, 2009, 6:28am wrote on May 5th, 2009, 6:20am:
What rating is this RCD? The new 17th edition requires 30mA protection to the majority, if not all circuits in a residential application. Having a single RCD covering the entire board does not comply - you need to split the installation into two halfs so if an RCD does trip you do not loose all power. The circuits should be split so that if an RCD fails, the lights in one area go out, but the sockets stay on, and vica-versa for the other half. |
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Title: Re: Rewireable fuses Post by Y3 on May 5th, 2009, 4:57pm Lectrician wrote on May 5th, 2009, 6:28am:
Although, this still doesn't fully comply with the 17th edition regs. Though a board full of RCBO's will>>>>> Expensive! |
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Title: Re: Rewireable fuses Post by Y3 on May 5th, 2009, 5:15pm The_Trician wrote on May 5th, 2009, 12:16am:
;D ;D ;D ;D ;D ;D I love it when you go on one, interesting that UK electrical equipment manufacturers are part of the IET, explains everything! |
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Title: Re: Rewireable fuses Post by Lectrician on May 5th, 2009, 5:37pm wrote on May 5th, 2009, 4:57pm:
Why not Carl? Them dual split loaders we are all using not up to scratch? Perhaps someone should let the manufacturers know! |
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Title: Re: Rewireable fuses Post by Y3 on May 5th, 2009, 8:30pm Like TT said, the manufacturers are on the board of the IET ;D |
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Title: Re: Rewireable fuses Post by Lectrician on May 5th, 2009, 8:32pm Yes, but seriously, why do you think that the 17th edition dual splits do not comply? |
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Title: Re: Rewireable fuses Post by plugwash on May 5th, 2009, 9:18pm The new RCD splits seem to me to be similar to the old split loaders. Everyone uses them but IMO they violate at least the spirit and possibly (depending on how you read it) the letter of the discrimination rules. |
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Title: Re: Rewireable fuses Post by Lectrician on May 5th, 2009, 9:23pm Discrimination is based on devices of the same kind......MCB's and MCB's, not MCB's and RCD's for example. |
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Title: Re: Rewireable fuses Post by Y3 on May 5th, 2009, 10:36pm Lectrician wrote on May 5th, 2009, 8:32pm:
Regulation 314.1 |
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Title: Re: Rewireable fuses Post by Lectrician on May 6th, 2009, 6:28am Don't turn into chubbs Carl - Regs are better as words, not numbers! Is this the reg that goes on about splitting up circuits as required to avoid hazards and inconvenience? If it is, then the 17th edition boards will satisfy this reg in the majority of houses. Some larger houses may need other consideration. For example, a larger house we did recently had two dual slit loaders. The boards where developed to give us a way to conform to these regs, and the design agreed not just by manufacturers! If you install one of these boards correctly you comply. |
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Title: Re: Rewireable fuses Post by ChubbyPhaseWire on May 6th, 2009, 10:16am wrote on May 4th, 2009, 11:22pm:
No Take a look at 533.1.1.2 ;) |
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Title: Re: Rewireable fuses Post by Y3 on May 6th, 2009, 9:35pm Lectrician wrote on May 6th, 2009, 6:28am:
Couldnt be bothered to type the whole lot out lec, sorry Lectrician wrote on May 6th, 2009, 6:28am:
Yes Lectrician wrote on May 6th, 2009, 6:28am:
Upstairs sockets with downstairs lights etc... on one RCD, and opposite way around on another RCD would cause inconvenience when a fault occurs. If a fault on one circuit is causing the loss of another circuit then this is an inconvenience. An all RCBO installation would fully comply, dual RCD split loads are only partially compliant, not fully. |
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Title: Re: Rewireable fuses Post by Lectrician on May 6th, 2009, 9:51pm A single circuit tripping is also an inconvenience. At the end of the day these boards where designed to comply with the regs, and will fly through an inspection if done correctly. A board full of RCBO's is excellent, but not going to happen in the majority of cases. |
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Title: Re: Rewireable fuses Post by Y3 on May 6th, 2009, 10:56pm Lectrician wrote on May 6th, 2009, 9:51pm:
To itself, not other circuits. The regulation doesnt mention a circuit causing an inconvenience to itself, but it does, to other circuits. All im saying is, they are not fully compliant, according to the reg |
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Title: Re: Rewireable fuses Post by LS on May 7th, 2009, 1:15am I think you're missing the point, the regulation stipulates minimizing inconvenience, not removing it completely. And the main objective after minimizing inconvenience is to reduce possible danger, which is why most contractors are adopting the sockets down with lights up approach. |
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Title: Re: Rewireable fuses Post by Lectrician on May 7th, 2009, 6:33am wrote on May 6th, 2009, 10:56pm:
Thats why I am arguing - because they DO comply. I'm sorry but I am going to disagree complety. Alot of consultation went on before these consumer units where put into production, the manufacturers didn't just take it upon themselves to design. There are best practice guides from the NIC which shows how to use the boards in regards correctly splitting circuits. |
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Title: Re: Rewireable fuses Post by Y3 on May 7th, 2009, 6:54am LSpark wrote on May 7th, 2009, 1:15am:
Im just thinking a fault on an upstairs ring that knocks out the downstairs lights is inconvenient, especially if its night time and the CU is downstairs somewhere. Some people have lights plugged in etc... to the downstairs ring, but not everybody (OAP's). Same goes if a fault on a downstairs ring knocks out the upstairs lights, people go toilet at night, no lights means a higher risk of tripping and falling down the stairs. BTW, the username LS is much better than the Krap one you had before ;D |
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Title: Re: Rewireable fuses Post by LS on May 7th, 2009, 8:32am wrote on May 7th, 2009, 6:54am:
Agreed..it just didn't work out well in reverse.. such a shame. ::) |
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Title: Re: Rewireable fuses Post by squirrel on May 7th, 2009, 8:56am Quote:
I think a bit of common sense should be applied to each installation. Most people, if they get up in the dark, will switch the bed side light on first. If socket cct has tripped they'll try the lights. As an aside to this if the CU is in a cupboard I fit a sperate feed from the non RCD for a cupboard light |
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Title: Re: Rewireable fuses Post by Lectrician on May 7th, 2009, 9:01am In my old house I actually have a maintained EM light fitting under the stairs where the consumer unit was. I had a door switch on the hinge side of the door which brought the light on in 'mains mode' so you could see under the cupboard for your shoes, and if the power failed the EM light would come on so you could find that dreaded B6 that had tripped! |
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Title: Re: Rewireable fuses Post by Y3 on May 7th, 2009, 6:28pm Lectrician wrote on May 7th, 2009, 9:01am:
Thats good thinking of you, not a lot of people would think to do that in their own home!! |
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Title: Re: Rewireable fuses Post by Goodsparks on May 7th, 2009, 8:10pm Quote:
Yep.... Some of us sad people would..... |
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Title: Re: Rewireable fuses Post by Y3 on May 7th, 2009, 8:26pm Thats really tidy. Whats the copex in the trunking for? What make consumer units are they? (they look really spacious) What's the top one for, I can see a timer there? Thanx for the pics on this one!! |
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Title: Re: Rewireable fuses Post by Goodsparks on May 7th, 2009, 8:59pm Kopex is for the alarm keypad on the other side of the wall. Boards are memshield, top one's for most of the switched lighting (bath / hall / outside) 24v contactors mean the lights will come on/off when the alarm is set (when I get around to finishing it all off). Seemed like a good idea at the time.......... |
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Title: Re: Rewireable fuses Post by LS on May 8th, 2009, 10:37am wrote on May 7th, 2009, 8:10pm:
Your an electrician so you don't count, ordinary persons usualy wouldn't know much about emergency lighting, or wouldn't consider it. And by the way, like your wiring, but it's a bit over-kill for domestic surely, still I guess we have a A-Type MEM SPN db too so can't really say too much ::) |
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Title: Re: Rewireable fuses Post by Lectrician on May 8th, 2009, 12:35pm I like the A boards from MEM - built to last. Must remember to order an incomer each time though - I seem to always forget when I use them! |
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Title: Re: Rewireable fuses Post by The_Trician on May 8th, 2009, 1:58pm I've only ever seen these A boards employed in installations where home automation is used. They must be bloody expensive. Not much change out of a couple of hundred for a 10 way without incomer & CPDs? Is the busbar all-insulated? I had to feed some bottom entry cables up behind the mcbs in one set-up, and was bricking it about an exposed unseen live busbar lurking behind the MCBs! TT |
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Title: Re: Rewireable fuses Post by Lectrician on May 8th, 2009, 2:30pm The busbar is enclosed in white plastic. Imagine their type B TP boards, shurnk and turned 90 degrees, with one side of the busbar not present.....if that makes sense! The A board is really just a single phase B board. They do expansion cabs which are the A board with no guts, just dinrail. These can be bolted to the top of the A or B boards and through wired. The A boards are not that much more expensive than their box standard metal clad range of single phase consumer units, but they do need the incomer which puts it up a tad. We use them fairly often in commercial applications and don't find the price too much of an issue. |
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Title: Re: Rewireable fuses Post by Twobarrows on May 8th, 2009, 2:35pm Nice one fatty, you consistenty add absolutely no value to this forum! wrote on May 6th, 2009, 10:16am:
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Title: Re: Rewireable fuses Post by Goodsparks on May 8th, 2009, 2:41pm 13 way board and the 15 way enclosure (top pic) that lec mentioned were about 80 quid the lot. MCBs and RCBOs were a mix of leftovers really. Really like the memshield 2 stuff, chunky and well made. (Gland plates take a bit of drilling with the 2" starret though as they are pretty thick) Got a dual rail 20 way merlin boad off ebay for the shed, that will be overkill :-) |
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Title: Re: Rewireable fuses Post by ChubbyPhaseWire on May 8th, 2009, 7:30pm wrote on May 8th, 2009, 2:35pm:
;) |
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Title: Re: Rewireable fuses Post by Y3 on May 8th, 2009, 8:05pm Lectrician wrote on May 8th, 2009, 12:35pm:
What do you mean by incomer? |
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Title: Re: Rewireable fuses Post by LS on May 8th, 2009, 8:30pm Main switch or RCD, double pole for single phase supplies. |
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Title: Re: Rewireable fuses Post by Y3 on May 8th, 2009, 8:44pm Cheers LS, I went on the eaton site and looked at all the distribution boards and came across the incomer part. |
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Title: Re: Rewireable fuses Post by howlingdog on Aug 23rd, 2009, 8:57pm Any installation wired before the 17th will most prob not comply. However, they have no need to provided that they complied with the regs in place at the time of installation. You can recommend that they be up-dated (Code2 - an un-just coade 2 as there would be nothing wrong with it) but it should be a code 4. Re '2 rcd split boards'. I'll just say that for me, they do not comply with the 17th. A fault on circuit 1 should not cause circuit 2 to fail! To me it would be the same as putting a rcd to control a 2-way board? 3036 fuses will comply provided the circuit has been designed with them in mind. (If I'm incorrect I shall stand in the rain for five days singing a Dylan song of your choice) Rob |
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