Replacing Fuse wire with MCBs

[JonoPashley]

I wouldn't say better at all - a MCB is a mechanical device and can fail.
A fuse is a piece of wire and providing it is not abused i.e. by replacing it with a larger piece of wire then it has got to be more reliable than an MCB.
I have had an MCB fail to operate before, also had some which had siezed up inside through getting damp.

Maybe not better in that respect but they are a huge increase in convenience.

 

[RF Lighting]

SCHEME PROVIDERS DO NOT WRITE THE REGS.. and as such their interpretation of them is exactly that, their interpretation.

I take it you're not with one then. They interpret the regulations correctly, sometimes with minor differences, I can compare, being with NAPIT and the NICEIC.

I worked for two NICEIC registered companies for over ten years and now work for an ECA registered company.

In all that time I can not cite one example of either scheme provider insisting that work complies with any other standard apart from BS7671

They do make some recommendations as to their preferred way of doing things, but as long as your work complies with BS7671 they is NOTHING they can do.

Can you imagine if they threw you out of their organisation for not complying with their standards (that you seem to have imagined), and you took them to court.

Judge : Did the work comply with the current British Standard?

You : Yes your honour

Judge : [to them] So, was this work unsafe?

Them : Erm, no.

Judge : So, what seems to be the problem?

 

[ban-all-sheds]

Well here I will spring to the defence of NICEIC/NAPIT/ECA/UTCAA

Regarding the generic point of having professional standards which exceed the "legally" required minima.

There is nothing wrong with that. Membership of any of these bodies is not compulsory, so if someone chooses to join one then it should be taken that they are choosing to work to their standards. Just like a car designer taking a job at <insert prestige manufacturer of choice> - in dong so he is choosing to work to their brand standards for safety/noise/economy/whatever, which could well be higher than the legislative minima.

I'm not convinced that if someone voluntarily signs up to work to a particular trade association standard which is in their Ts'n'Cs, freely agreed to, and which exceeds the requirements of BS 7671 that they would have a legal leg to stand on if they then failed to work to those standards. Just like if you worked for Lexus and you refused to make a car as quiet as they said you should on the grounds that the law didn't require it to be that quiet.

 

[ColJack]

the problem with your analogy BAS is that in working for a car manufacturing company, they are paying YOU and therefore have the right to insist that to get paid you must work to their standard..
being a memeber of the schemes mean YOU pay THEM..

 

[ban-all-sheds]

Yes, but you have full sight of their Ts'n'Cs before you sign up.

 

[ColJack]

Yes, but you have full sight of their Ts'n'Cs before you sign up.

do you get a FREE copy of their codes of practice and guide to electrical installation before you sign up? so that you can see to what you're agreeing to work to?

 

[ban-all-sheds]

IHNI.

I do know though that no terms or conditions can be enforced if they are not made available before you sign up to them.

 

[Jaymack]

You're on the correct forum for your views.

Last word - Word!

Regards

 

[THRIPSTER]

Try reading this ..............it may help.



http://www.theiet.org/publishing/wiring-regulations/mag/index.cfm



The article you need is entitled 'Additions and alterations'.


Regards

 

[THRIPSTER]

Shame that the people that write this do not understand that, in most cases, people will not be willing to fork out for a periodic and then for the remedial work - probably pertinent to domestic situations. They should separate commercial and domestic regulations and make sure that the latter is workable (and still safe) within the constraints placed by what happens in practice. Unless rigorously enforced, what they are recommending is just not going to happen.

Regards

 

[ban-all-sheds]

That article has been discussed here before.

It's utter madness, to the extent that Mark Coles cannot possibly be right.

"The installer
does not simply take
responsibility for the newly
installed or reconfigured
element of the installation but
all parts of the circuit(s)
worked on"

Unless you remove every single accessory, and hack away at all of the walls, lift all of the floors and/or drop all of the ceilings, and if applicable dig up gardens, driveways, patios etc so that every single mm of every single cable is fully exposed for inspection and verification of compliance with every single regulation which applies then you cannot take responsibility for all parts of the circuit(s) worked on.

 

[dave-lew99]

Aaannnnddd to bring us back to the topic...

I had some time today (finally) to do some looking about properly and i've found what runs of what fuse so here goes:

32A / Labelled as Ring Main

3x Double Socket (Living Room)
1x Single Socket (Upstairs Landing)
2x Double Socket (Bedroom)
2x Double Socket (Office)
1x Fused hard-wired spur for combi boiler (Airing cupboard)

32A / Labelled as Spare

1x Single Socket (Downstairs landing)
2x Double Socket (Kitchen)
Electric Oven (Kitchen) (with 13A fused switch)
Hob Ignition (Kitchen) (with oven)
Extractor Fan - plugged into double socket on 13A fused switch
1x Double Socket (Utility Room)
2x Double Socket (Utility Room - each with own 13A fused switch)
1x Double Socket (Utility 2)
Utility 2 Ceiling light
(Last two fed from single 13A fcu)

5A / Labelled as 'Lights/Downstairs/Back of flats'

Strip light (looks to be 6') (Kitchen)

5A / Labelled as 'Lights'

Hallway light
Landing/Stairs lights (2 wired together)
Bedroom Light
Toilet Light
Bathroom Light
Office Light
Living Room light

Now here's where it gets interesting, the lights in both the utility room and it's nearby cupboard don't work - no idea where they could be wired into. There is also a fused switch in the kitchen, which when i put a fuse into it, did absolutely nothing!

And the potentially dangerous one - there is a double socket in my hallway which is not fed from my CU. Since the shop next door has 3-phase which has it's distros and meters in my front hall, these sockets are potentially on a different phase. So should something fault there's a potential for 415v across something.

I took some photos, sorry not all of them came out - they looked ok on my phone though!

http://gallery.lewty.org.uk/main.php?g2_itemId=3354

 

[IJWS15]

Plug-in MCB's are no longer a cheap fix for a professional electrician, you would be installing MCB's when RCD protection is also now required to the 17th, unless the cable runs don't merit it - improbable though. An EIC is required to confirm each circuit Zs is within limits, the circuitry is healthy and all main bonding is correct. It would also be notifiable to the LBA.

Questions from an amateur -

1. Is a High Zs or a low Zs better
2. Does an MCB require a higher or lower Zs measurement than a re-wireable fuse.
3. If the ZS is out of tolerance for an MCB WOULD it also be out of tolerance for a re-wireable fuse?

I did this switch in our last house about 12 years ago - never had an issue and meant that the wife did not have to worry about re-wiring fuses when I was abroad on business - just pressed the button back in.

 

[ban-all-sheds]

1. Lower.
2. Require is the wrong word - it can tolerate a higher Zs. Or to put it another way, a rewirable fuse requires a lower Zs.
3. Definitely.

There's an explanation here.

 

[IJWS15]

1. Lower.
2. Require is the wrong word - it can tolerate a higher Zs. Or to put it another way, a rewirable fuse requires a lower Zs.
3. Definitely.

There's an explanation here.

So on that basis is it not correct to say that if testing shows that a circuit cannot support an MCB it also cannot support a re-wireable fuse and whilst the regs say it should be tested the circuit will be SAFER with the re-wirable fuse swopped for an MCB.

Surely a case of rules gone mad.