Increase mcb capacity. Notifiable?

[spynage]

Went to a house yesterday where the customer was complaining of a tripping fuse on the kitchen circuit.

Got there and found the kitchen wired to a 20amp plug in MCB. The kitchen was not on a ring despite 2 wires being present in the board.

I confirmed a break in the circuit but didn't resolve wether it was a disconnected wire or a break somewhere. I was in a hurry I have to admit and made the assumption that someone with some insight deliberately derated the circuit to account for there being an irreconcilable break so I ruled out a loose wire.

I advised that she would require a new fuse board if I was to make good the wiring in the kitchen. Afterwoods however I wondered if perhaps there was a loose connection.

If so and I repaired this could I upgrade the capacity of the MCB to 32amp under current regs?

cheers.

 

[camerabloke]

Why did you say a new consumer unit?

 

[GMES]

As above ^^^

 

[Plonker 3]

As above too.

Also what are they using in the kitchen to trip a 20 amp MCB?

 

[dan86]

^^as above also^^

 

[telectrix]

if OP is making alterations to a socket circuit, then it's advisable to fit RCD protection, as his work has to be to current regs. maybe that's why he's advised a new CU.

 

[spynage]

As above too.

Also what are they using in the kitchen to trip a 20 amp MCB?

They are using all the equipment. There is an oven w/m new kettle toaster fridge micro, nespresso maker etc. It goes after 5 or 10 mins.

i said if new wiring was required to join the ring then it would require a 17th edition board.

 

[camerabloke]

Find the fault first before selling things that may not be needed. Surely that's the way to go

 

[Plonker 3]

You need to prove it was a ring first. If it was you can merely replace the cable same route etc and no RCD would be required. If you are turning 2 radials into a ring then simply put a stand alone RCD at the DB rather than install a whole new board.

 

[spynage]

You need to prove it was a ring first. If it was you can merely replace the cable same route etc and no RCD would be required. If you are turning 2 radials into a ring then simply put a stand alone RCD at the DB rather than install a whole new board.

Theres only like 6 circuits in the whole house. I think a separate RCD unit would be a messy solution when there's a 3036 board that could be updated at the same time for not much extra cost.

Im not selling anything. Just following the regs. New wiring requires RCD in the kitchen. That's why zi want to know if upgrading the current MCB is permissible. Saves the lady some money.

 

[GMES]

This is the problem these days Imo, it seems easier to start from scratch than to take the time to find the problem and rectify, Not a pop at the op, but sometimes with a bit of thought it is not hard to to make good what you already have in front of you.

 

[Plonker 3]

New wring yes, existing wiring no.

If as you suspect it's a broken cable, simply replace it like for like same route etc and no RCD.

By all means explain the advantages of a new DB but it really isn't needed even if you have to install a brand new cable, just a stand alone unit as I have already said.

 

[spynage]

This is the problem these days Imo, it seems easier to start from scratch than to take the time to find the problem and rectify, Not a pop at the op, but sometimes with a bit of thought it is not hard to to make good what you already have in front of you.

With that in mind can I upgrade the MCB or not?

 

[Plonker 3]

Yes if you can prove the cable is capable of carrying the current of the new OCPD.

 

[dan86]

now, forgive me if I am reading this wrong, but I am still on holiday, it's warm, and I've had a few.
but from what I've read it seems the customer has a 20a mcb in their kitchen which is tripping.
in order to rectify this, you want to swap for a 32a?

 

[dan86]

deleted

 

[spynage]

now, forgive me if I am reading this wrong, but I am still on holiday, it's warm, and I've had a few.
but from what I've read it seems the customer has a 20a mcb in their kitchen which is tripping.
in order to rectify this, you want to swap for a 32a?

Correct!

Just want to know if that's notifiable? If it is then notifiable work in a kitchen would mean installing RCD protection would it not?

 

[Plonker 3]

No, electric work in a kitchen doesn't always need RCD protecting.

Are you a electrician?

 

[telectrix]

1. it's not notifiable as it's not a new circuit. 2. it's optional whether or not you fit RCD> personally i would prefer to fit one if the customer was happy to pay.

 

[Andy78]

Correct!

Just want to know if that's notifiable? If it is then notifiable work in a kitchen would mean installing RCD protection would it not?

You seem confused about a great many things. What does it being notifiable or not have to do with the requirements for RCD protection ?

 

[spynage]

1. it's not notifiable as it's not a new circuit. 2. it's optional whether or not you fit RCD> personally i would prefer to fit one if the customer was happy to pay.

Ok. So upgrading the current carrying capacity of a circuit is not notifiable? Really?? Just a MWS then?

 

[dan86]

I'm confused.
kitchen circuit is tripping the 20a mcb, so your solution is to bang in a 32a instead?
have you done any testing at all. if so, what?
as for notifiable- no. as for rcd- your responsibility is to explain to the customer what protection that will offer and let them decide.

 

[dan86]

Ok. So upgrading the current carrying capacity of a circuit is not notifiable? Really?? Just a MWS then?

what?
now I definitely know you are confused!

 

[spynage]

No, electric work in a kitchen doesn't always need RCD protecting.

Are you a electrician?

I want know if increasing the capacity of a circuit from 20 amp to 32 amp is notifiable. As far as RCD protection goes then if I'm putting new wiring in a special location with no additional protection then I would expect to put in place An RCD.

 

[Andy78]

Ok. So upgrading the current carrying capacity of a circuit is not notifiable? Really?? Just a MWS then?

But by replacing a 20A for a 32A you wouldn't be "upgrading the current carrying capacity of a circuit" would you ? As said a few times already..... is the cable suitable for the new size MCB you plan to fit ?

 

[telectrix]

since when is a kitchen a special location? if you can reinstate the RFC then do so, then uprate to 32A. if not, leave well alone.

 

[dan86]

I want know if increasing the capacity of a circuit from 20 amp to 32 amp is notifiable. As far as RCD protection goes then if I'm putting new wiring in a special location with no additional protection then I would expect to put in place An RCD.

you would not be increasing the current capacity of a circuit by swapping the 20a with a 32a. you would merely be changing the OCPD.
the only way to alter the CCC of a circuit is to install a new circuit with the relevant size cable and OCPD.

 

[tony mc]

Have you found the fault ? If there is one ?

Maybe this will help as you should have a copy or a good working knowledge of it if you are working in peoples homes!!

New Approved Document P: Electrical safety - Dwellings

 

[spynage]

you would not be increasing the current capacity of a circuit by swapping the 20a with a 32a. you would merely be changing the OCPD.
the only way to alter the CCC of a circuit is to install a new circuit with the relevant size cable and OCPD.

Thanks.

So if I reinstate the ring then I can upgrade the MCB to 32amp and just issue a MWS. If the circuit requires new wiring which can't fulfil all the conditions of 522.6.101 then Ill insist it requires some form of RCD protection.

 

[tony mc]

What do you mean new wiring ?

 

[camerabloke]

Hazard a guess between the break. Although it could just be a loose connection if he puts some time into testing

 

[telectrix]

be more concerned with 411.3.3, although 522.6.101 is relevant. have you determined whether it's a damaged RFC or 2 separate radials? whatever the case, the most important measure is to comply with Ib<In<Iz

 

[Plonker 3]

Thanks.

So if I reinstate the ring then I can upgrade the MCB to 32amp and just issue a MWS. If the circuit requires new wiring which can't fulfil all the conditions of 522.6.101 then Ill insist it requires some form of RCD protection.

The CCC of the cable must be able to carry the current of the OCPD, only testing and calculations can tell you this.

 

[spynage]

Hazard a guess between the break. Although it could just be a loose connection if he puts some time into testing

I did say that. The circumstances were I was rushing, I didn't charge her anything and made a suggestion on the spot that should upgrade the 6 way 3036 board for a 17th edition if new wiring was required in the kitchen.
As it had been purposely de-rated to 20amp I assumed someone in the past couldn't reconcile the ring by making a simple re-connection.
I haven't quoted her yet. Worst case scenario is still a new board IMO. I'll quote her for reconnecting the circuit and upgrading the MCB if it's permissible. I would of thought that would require more than a MWS?

I know I need to test the circuit if I'm adding a larger OCPD

 

[Octopus]

FFS test the circuit THOROUGHLY and once you've done that only YOU will know what is feasible. You need to test the circuit to find the fault!

Do you have test equipment?

 

[camerabloke]

What he said ^^^^

 

[Plonker 3]

..........

 

[Meggerman]

Went to a house yesterday where the customer was complaining of a tripping fuse on the kitchen circuit.

Got there and found the kitchen wired to a 20amp plug in MCB. The kitchen was not on a ring despite 2 wires being present in the board.

I confirmed a break in the circuit but didn't resolve wether it was a disconnected wire or a break somewhere. I was in a hurry I have to admit and made the assumption that someone with some insight deliberately derated the circuit to account for there being an irreconcilable break so I ruled out a loose wire.

I advised that she would require a new fuse board if I was to make good the wiring in the kitchen. Afterwoods however I wondered if perhaps there was a loose connection.

If so and I repaired this could I upgrade the capacity of the MCB to 32amp under current regs?

cheers.

Were all r1, rn and r2 all broken? Maybe it would be suitable to separate into two 20A radials to increase capacity depending where loading is. It is always a good idea to add RCD protection to socket outlets when opportunity arises. I agree RCD add ons is untidy. Do it right with a new CU. I talk them round and upgrade 3036 / 1361 boards whenever I see them in houses.

 

[davek]

Just too fuel the fire but also trying to help my fathers old house has a problem blowing Fuses now I went round check it out. My father said it blows after 5-10 min with nothing running. On investigation it was the cable under the floor wher it entered up the wall was being crushed by the chipboard flooring as his washer was leaking at the back causing it to swell plus damp further more a jb inder the floor had melted (which went first). Taking that it will be an old wylex box may be something similar. so a kind cowboy riding through though down rate it

 

[Plonker 3]

The thing is, the OP is more interested in fitting a new DB rather finding either the fault or clamping the circuit and seeing what it is actually pulling.

 

[GMES]

The thing is, the OP is more interested in fitting a new DB rather finding either the fault or clamping the circuit and seeing what it is actually pulling.

No offence meant to the op here but if he did a short course, then he probably doesn't even know what a clamp is, they don't show them.
Not saying he is a short course guy.

 

[topquark]

BS951 clamp? :54:

 

[spynage]

Were all r1, rn and r2 all broken? Maybe it would be suitable to separate into two 20A radials to increase capacity depending where loading is. It is always a good idea to add RCD protection to socket outlets when opportunity arises. I agree RCD add ons is untidy. Do it right with a new CU. I talk them round and upgrade 3036 / 1361 boards whenever I see them in houses.

Thanks. That's my thinking exactly, particuarly as the customer indicated that the rest of the electrics were in disaray. Just R1 actually
I said I was in a hurry and didnt have time to fully test the circuit.

It was the precence of the 20amp MCB that made me assume it hsf been fitted as a last resort. There was 2 wires in the fuse clamp.

I still dont know wether changing the type of circuit arrangment and increasing the circuit breaker cspacity is notifiable? Is there a reg that could help me in this respect? How much of a circuit amendment does it constitute?

 

[spynage]

The thing is, the OP is more interested in fitting a new DB rather finding either the fault or clamping the circuit and seeing what it is actually pulling.

Can I just point out your willfully ignoring the point of my post. I only want to know if increasing the MCB capacity is notifiable and only because I want to do the best by my customer for her to spend as little money as possible to rectify the problem. If I only wantef to change CU's day in day out I wouldn't come on here seeking enlightenment.

 

[trev]

So you have a "potential RFC" with only the r1 broken? and you're asking what the way forward is?

It needs to be sorted mate before you think about uprating a breaker. You have continuity on the other cables. That's a massive clue.

 

[davesparks]

It is a ring circuit with a fault, regardless of the size of the MCB.
Find the fault and fix it first, then discuss potential upgrades and improvements with the customer.

 

[Meggerman]

Thanks. That's my thinking exactly, particuarly as the customer indicated that the rest of the electrics were in disaray. Just R1 actually
I said I was in a hurry and didnt have time to fully test the circuit.

It was the precence of the 20amp MCB that made me assume it hsf been fitted as a last resort. There was 2 wires in the fuse clamp.

I still dont know wether changing the type of circuit arrangment and increasing the circuit breaker cspacity is notifiable? Is there a reg that could help me in this respect? How much of a circuit amendment does it constitute?

No, it is not notifiable under Part P, you can download Part P regulations for free if you don't want to buy guide. it is a repair to an existing circuit. It was a ring final in the first place which has been derated, you are carrying out a repair.

 

[davesparks]

How do you know it was a 32A ring to start with?
It is not all that uncommon to find 20A rings in instsllations, but don't ask me why people have installed them as I've yet to find one where it could be justified for volt drop reasons etc.

IMO altering the circuit from a 20A cct to a 32A cct is equivalent to creating a new cct as you would be starting from scratch with doing all design calcs before carrying out the work.

 

[Meggerman]

How do you know it was a 32A ring to start with?
It is not all that uncommon to find 20A rings in instsllations, but don't ask me why people have installed them as I've yet to find one where it could be justified for volt drop reasons etc.

IMO altering the circuit from a 20A cct to a 32A cct is equivalent to creating a new cct as you would be starting from scratch with doing all design calcs before carrying out the work.

In the time you had sat talking about design calcs on a STANDARD CIRCUIT, I would have found the break, rectified it, and on the the next one.... Bloody hell.....

 

[spynage]

No, it is not notifiable under Part P, you can download Part P regulations for free if you don't want to buy guide. it is a repair to an existing circuit. It was a ring final in the first place which has been derated, you are carrying out a repair.

Ok. It seems obvious it was a ring that was derated. I just wasn't sure if putting it right constituted something notifiable ad Im uprating the MCB.

For various reasons I didn't undertake a full investigation. I wasnt 100% about the customer and I didnt want to poke about reconnecting wires and pointing out what the problems were. I thought better to tske stock and quote her for the potential outcomes of the work. She is aware of the problem(s) and she now has a quote for both msking good the defective circuit and for any other potential work that may or may not include new wiring or perhaps a new CU