Replacing Fuse wire with MCBs

[dave-lew99]

As far as i can tell, i never saw it before the work was done - they've moved the room the kitchen was in and added a load of new double sockets in the kitchen, utility room and second utility room.

Each pair of double sockets has it's own 13A fused switch, the cooker and extractor fan have individual 13A fused switches.

The light in the very back room has it's own 13A fuse. Lights are all fed off main house lighting circuit (Fused at 5A) and the sockets including oven seem to be fed off 30A fused marked 'spare'

There is also a fused switch with no fuse in it which does not seem to affect anything.

From memory thats all i can remember, i'm going over tomorrow afternoon so i'll make some notes, if i remember to i'll check cable thickness etc - some of it is exposed in cuboards and the like.

Oh, the other one is that it's a maisonette flat and some of the wiring for the shop next door runs through one of my cupboards and in the shared hall is the 3 meters for their three phase supply.

It's an...interesting...property to say the least.

Oh some, (bad, none electrical specific) pictures, here

www.lewty.org.uk/house

 

[Jaymack]

This would be similar to changing the DB, it would be notifiable, if it were allowed to the 17th edition of the wiring regulations - All the wiring would require RCD protection unless the cable was buried in the walls >50mm or run on the surface.

Regards

 

[ban-all-sheds]

You do not have to add RCD protection to circuits if you replace fuses with MCBs.

The way some people exaggerate the scope of their work in order to claim that further upgrades are necessary is staggering, to the extent that I'd not be surprised to see claims that electricians aren't even allowed to enter someone's house unless the earthing and bonding is upgraded.

 

[AndyPRK]

I thought all rented places had to have MCB's or the fuses locked/screwed away.

Personally I wouldn't bother changing them.

 

[dave-lew99]

Personally I wouldn't bother changing them.

Normally i wouldn't either but i have been known to trip power now and then when something has gone faulty - i get through a lot of second hand IT kit.

 

[Jaymack]

You do not have to add RCD protection to circuits if you replace fuses with MCBs.
The way some people exaggerate the scope of their work in order to claim that further upgrades are necessary is staggering, to the extent that I'd not be surprised to see claims that electricians aren't even allowed to enter someone's house unless the earthing and bonding is upgraded.

You would be altering the circuit characteristics, so requiring an EIC, RCD protection would also be required to the 17th edition. If you are with a scheme provider, confirm it with them!

Regards

 

[ban-all-sheds]

You would be altering the circuit characteristics, so requiring an EIC

Yes - to cover the work that you do.

You aren't installing anything which requires RCD protection.

RCD protection would also be required to the 17th edition.

Which regulation requires MCBs to be RCD protected?

If you are with a scheme provider, confirm it with them!

They're also populated by people who can't read.

 

[kevindgas]

quite frankly on this I would consult your Landlord see that he is happy with it being done. change like for like and who's gonna give a toss!!

at the end of the day the Mcb is more likely to trip than the wire is to blow
and nobody will be any the wiser.

but if you have any doubt on the electrics in the property don't proceed.

 

[Jaymack]

If you are with a scheme provider, confirm it with them!

They're also populated by people who can't read.

NAPIT and the NICEIC will be pleased to hear of that criticism, this is a DIY forum, care should be exercised in giving advice which is contrary to the regulations.
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. Anyone with a stock of these plugin MCB's have a white elephant. 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.
It's easier to replace the fuseboard, it is no longer possible to use plug-in MCB's to replace fuses, although one could be used for 'like for like' replacement.

Regards

 

[ban-all-sheds]

NAPIT and the NICEIC will be pleased to hear of that criticism,

How many examples of them getting it wrong do you need?

this is a DIY forum, care should be exercised in giving advice which is contrary to the regulations.

I am not giving such advice.

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,

You are not required to bring every aspect of existing installations up to current standards.

An EIC is required to confirm each circuit Zs is within limits, the circuitry is healthy and all main bonding is correct.

Yes, but the EIC does not have to state that the entire circuit complies with every single relevant 17th regulation.

If you think that it does have to, and that is why you have to add an RCD so that you can issue an EIC, what do you do about 522.6.6 and 522.6.8?

And 522.6.5?

And 521.10.1?

And 526.3?

And 522.8.10?

And.... ?

And.... ?

And.... ?

Are you finding it hard to get work because you want to hack at all the walls, lift floors, drop ceilings and dig up gardens so that you can sign an EIC certifying that the circuit(s) you've worked on comply with all aspects of the 17th?

It would also be notifiable to the LBA.

I'm not convinced about that.

It's easier to replace the fuseboard, it is no longer possible to use plug-in MCB's to replace fuses, although one could be used for 'like for like' replacement.

Fine - you tell that to your customers who you want to hoodwink into paying for extra work, but please don't try it on here.

 

[Jaymack]

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,

You are not required to bring every aspect of existing installations up to current standards.

You conveniently ignore the crux - that the RCD protection is required because the cables are installed in walls <50mm for an existing installation!

[Yes, but the EIC does not have to state that the entire circuit complies with every single relevant 17th regulation.

It's an installation carried out to previous regulations - acceptable at that time, however, all work carried out since the introduction of the 17th edition, requires to conform with that edition, i.e. in this case - installation of an RCD for most circuits including lighting and power!

An irresponsible DIY person can replace fuse carriers with MCB carriers, since he is not being paid for his efforts and is probably, blissfully unaware of the new regulation requirements for RCD's; and the need to verify that Zs, IR and the main bonding etc., is correct. An electrician worthy of his salt shouldn't do it.

Regards

 

[Spark123]

Bit of an awkward one - I know that the NICEIC etc like to push to bring things up to current standards within reason. You cannot sign to say things are installed to the standard if you did not install them as without destruction you will never know.

However if you read the first part of 131.8 - "No alteration or addition, temporary or permanent, shall be made to an existing installation, unless it has be ascertained that the rating and condition of any existing equipment, including that of the distributor, will be adequate for the altered circumstances."

So to alter the circuit parameters you firstly need to ensure that it will disconnect correctly but you then have to ask if the circuit is now adequate for the altered circumstances, does it need to have RCD protection for the altered circumstances?
I have a feeling most sparks will like to put it on RCD as it is a reasonable step towards it, I for one am not going to preach that in doing this that it is wrong.

 

[ban-all-sheds]

You conveniently ignore the crux - that the RCD protection is required because the cables are installed in walls <50mm for an existing installation!

Yes, but you didn't install them when the 17th was in force, so there's no requirement for you to make them comply with the 17th.

It's an installation carried out to previous regulations - acceptable at that time, however, all work carried out since the introduction of the 17th edition, requires to conform with that edition, i.e. in this case - installation of an RCD for most circuits including light and power!

Yes - all work carried out.

As the work you are carrying out is not the installation of cables concealed in walls or partitions then the regulations that pertain to cables concealed in walls or partitions do not apply to your work.

A irresponsible DIY person can replace fuse carriers with MCB carrier's, since he is not being paid for his efforts and is probably, blissfully unaware of the new regulation requirements for RCD's; and the need to verify that Zs, IR and the main bonding etc., is correct. An electrician worthy of his salt shouldn't do it.

Regards

And an irresponsible electrician being paid for his efforts will misrepresent the regulations in order to get more money?

I'll repeat my question from earlier, since you obviously missed it.

If you think that replacing a fuse with an MCB requires you to do additional work to ensure that existing parts of the installation which you are not touching comply with 522.6.7, what do you do to ensure that they comply with 522.6.5, 522.6.8, 522.6.5, 521.10.1, 526.3, 522.8.10 etc etc etc?

 

[Spark123]

I can imagine a few angry faces if one week I replaced a consumer unit, then the following week they wanted something added which I say I cannot do without RCD protecting the circuit at the consumer unit

 

[Jaymack]

I'll repeat my question from earlier, since you obviously missed it.
If you think that replacing a fuse with an MCB requires you to do additional work to ensure that existing parts of the installation which you are not touching comply with 522.6.7, what do you do to ensure that they comply with 522.6.5, 522.6.8, 522.6.5, 521.10.1, 526.3, 522.8.10 etc etc etc?

Fit an RCD.