can I replace mcb myself ?

EFLImpudence said:

I realise that you are on a losing battle as they are not going to back down, but perhaps they will have learned something and will be better in the future.

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I won't be holding my breath!

I understand that the new PRS legislation requires that C1s/C2s be remedied within 28 days. However, I wonder what the situation would be if one commissioned (and, unfortunately, had to pay for) a second EICR by someone else (after having carefully interrogated the 'someone else' to ascertain his views about the 'contentious' issues) and that second EICR indicated that the installation was 'satisfactory' (i.e. without the 'incorrect' C2s) - if one waved that new EICR at the PTB, would they perhaps have to accept it (particularly given that it would be 'more recent')??

As far as the OP is concerned, a second EICR could well cost as much as the unnecessary remedial work, so this approach may well not be cost-effective, even if it might work! I suppose a sympathetic electrician might be prepared to undertake (for relatively little cost) a very limited-scope EICR which just looked at the things which had been given C2s in the first one.

Kind Regards, John

Thanks for that, Ill have a think what to do next.

We have been concentrating on the shower circuit, but even more worrying is the C2 for the single socket circuit with 32A MCB and 2.5mm² cable and the stated non-compliance with the same regulations even though it is protected against overload by the 13A plug fuse.

This is such a common occurrence, albeit more usual that the circuit shares the MCB with a ring circuit, that it does show that the 'inspector' is not really up to the job.

EFLImpudence said:

We have been concentrating on the shower circuit, but even more worrying is the C2 for the single socket circuit with 32A MCB and 2.5mm² cable and the stated non-compliance with the same regulations even though it is protected against overload by the 13A plug fuse. .... This is such a common occurrence, albeit more usual that the circuit shares the MCB with a ring circuit, that it does show that the 'inspector' is not really up to the job.

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I agree. Given what they have said about the shower circuit, I guess they'd probably try to invoke the argument that someone might come along in the future and (incorrectly) add more sockets. However, as I've said, I don't personally think that an EICR should attempt to anticipate possible future stupidity (and, if it did, as you imply, every unfused spur from a ring final would presumably get a C2 !).

Kind Regards, John

Yes, and as for your 'silly extremes', it could be that all socket circuits warrant a C2 because someone might fit a higher rated MCB - or connect a shower to it.

hi, why does a shower not need overload protection please ?

...because their elements cannot draw more amps than their resistance allows.
The resistance is the only constant. It cannot decrease.

Their rating - 9.5kW is determined by the voltage divided by their resistance

So, in whole numbers - 240 Volts / 6 ohms = 40 Amps,

then Amps times Volts - 40 x 240 = 9600 Watts.

It is true that should the voltage rise the current will rise but this is allowed for in the given cable ratings.

EFLImpudence said:

Yes, and as for your 'silly extremes', it could be that all socket circuits warrant a C2 because someone might fit a higher rated MCB - or connect a shower to it.

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Exactly.

... and there's no end to such potential silliness. Even though the cable would not be at risk (provided the MCB were appropriate), it would nevertheless be non-compliant if someone connected a shower to a lighting or immersion circuit (or an immersion to a lighting circuit).

Even an MOT test does not attempt to anticipate alterations to the vehicle which might be made after the test!

Kind Regards, John

EFLImpudence said:

It is true that should the voltage rise the current will rise but this is allowed for in the given cable ratings.

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Indeed, and even then the current would not rise as much as one might expect - because, at higher voltage, it would get hotter, hence the resistance would increase, which in term would reduce the increase in current.

Before some clever Joe jumps in, one can hypothesis certain, incredibly improbable/rare, situations in which a shower (or suchlike) might conceivably cause an overload, but the regulation which allows omission of overload protection only requires that the load is unlikely to result in an overload - and that's certainly the case with a shower or any other load which consists primarily of an essentially resistive heating element (e.g. ovens etc.).

Kind Regards, John

To prevent this grief every year (of when you get a new tenant, whatever)

Put the 6mm on a 40A MCB
and the 2.5mm cable socket on a 20A MCB (or 16 or 25 if easier to source)

It is a good compromise between functionality and safety

Yeah change them yourself

The question is does the MCB protect cable or appliance? this is repeated many times, we are told 16 amp max for lighting and since many ceiling roses rated 6 amp in the main we say 6 amp max. However typical house 8 rooms at 100 watt so can't exceed 4 amp even with LED bulbs, but if it had a 20 amp MCB it would be a fail, OK in the main because when a bulb blows you can get ionisation so yes can hit the 30 amp required to trip a B6 in 0.01 seconds, and a faulty shower element can also draw well over it's rated valve, we hope the RCD will protect, but I can see the point, there is no fuse inside the shower so yes potentially dangerous.

But to change a MCB is so easy and cheap, it is not worth arguing about, just change it.

JohnW2 said:

I understand that the new PRS legislation requires that C1s/C2s be remedied within 28 days. However, I wonder what the situation would be if one commissioned (and, unfortunately, had to pay for) a second EICR by someone else (after having carefully interrogated the 'someone else' to ascertain his views about the 'contentious' issues) and that second EICR indicated that the installation was 'satisfactory' (i.e. without the 'incorrect' C2s) - if one waved that new EICR at the PTB, would they perhaps have to accept it (particularly given that it would be 'more recent')??

As far as the OP is concerned, a second EICR could well cost as much as the unnecessary remedial work, so this approach may well not be cost-effective, even if it might work! I suppose a sympathetic electrician might be prepared to undertake (for relatively little cost) a very limited-scope EICR which just looked at the things which had been given C2s in the first one.

Kind Regards, John

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As far as I was aware a C1 should be corrected before the inspector leaves, even if simply locking off the circuit, 28 days is for C2 or F1.

There has always been a problem where inspectors have got it wrong, I have been to a property where a C2 has been awarded with only info being down stairs sockets, and you have to inspect every last socket and every place they could possibly see cable, and simply can't find a fault, and you don't simply think oh he got it wrong, you thing what has he seen, and one has to be super careful not to miss anything, at least with this one you know what he has seen.

I agree it seems daft doing unnessary work, but the question is not is the work requested daft, it is can the landlord DIY the work? I would say answer has to be yes, but that raises the next question, what paperwork is required?

So a receipt for new MCB to a minor works certificate, what would the county council accept as proof the work has been done without causing any other faults? And I will be frank I don't know.

ericmark said:

The question is does the MCB protect cable or appliance? ...

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If that is the question, then the answer is very simple - since there appears to be no doubt that, as far as BS7671 is concerned, it is there simply to protect the cable. As you are aware, the only requirement is ...

BS7671:2018 said:

433.1.1 The operating characteristics of a device protecting a conductor against overload shall satisfy the
following conditions:
(i) The rated current or current setting of the protective device (In) is not less than the design current (Ib) of the
circuit, and
(ii) the rated current or current setting of the protective device (In) does not exceed the lowest of the current carrying
capacities (Iz) of any of the conductors of the circuit, and ...

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In other words, as usually expressed, the requirement is "Iz ≥ In ≥ Ib", without any qualification anywhere. Hence, say, a dedicated circuit consisting of 6mm² cable protected by a 40A MCB supplying a hard-wired load of 0.1A would be totally compliant with BS7671 (even if silly).

BS7671 says nothing about OPDs protecting connected equipment and, if you think about it, it couldn't. For a start, as often discussed here, if a piece of equipment needs over-current protection, that should be provided within the equipment. Even if that is not done, there is no way that BS7671 could know what level of protection (rating of OPD) was required by any particular piece of equipment, so t could not specify any requirements,

ericmark said:

As far as I was aware a C1 should be corrected before the inspector leaves, even if simply locking off the circuit, 28 days is for C2 or F1.

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As has been said many times before, if an inspector has been engaged to just 'inspect' (and test), that is all that he/she can do. Desirable though it might be for a C1 to be rectified immediately, if someone engaged only to inspect undertook work on the installation (let alone 'locking off a circuit', or the whole installation) without appropriate authorisation from the owner of the installation (and, worst of all, if the owner of the installation 'forbade' such interference), then I think that person would be on the wrong side of the law.

Even the "28 days" (for C1, C2 and F3) only exists in relation to the recent 'PRS' legislation. In general, there is no obligation on a person who commissions an EICR to take any action with regard anything 'coded' on an EICR, ever.

ericmark said:

There has always been a problem where inspectors have got it wrong, ...

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Indeed, and I think the situation is much worse now - since, in some contexts, complying with the 'requirements' of an EICR (as you say, within 28 days) has become required by law. Prior to this new legislation (and still, other than for 'PRS' properties), if one did not like or agree with the findings in an EICR, one was always free to simply ignore it.

As I said recently, given that those undertaking inspections for the purpose of this new legislation now have the 'power' to require (enforceable by law) that certain works be done, I think what we need is a situation in which people undertaking inspections for that purpose have to be 'licensed ' so to do, for there to be an effective appeals/grievance procedure in place, and for those who are shown to have incorrectly 'required' that unnecessary 'remedial' work should be done should have their licences revoked, for life.

Kind Regards, John

There is an allowance for a cable reasonable protected from damage to be protected at destination as long as not branches and under 3 meters long. Many feel that does not apply to a ring final, however this is up to the inspector.

Yes you can't turn or lock off a dangerous supply without authorisation however you can't test without turning off, and clearly if faulty you can't turn it back on. Under the HSE rules and electrician can over ride the orders of a managing director to prevent danger in fact he is required to do so, which is in real terms daft as he would be sacked, but not sure if he can lock off, as he may not be the one to do repairs, but dropping tails would likely be permitted, and clearly he can't turn it back on.

British law says if you break the law to stop a greater crime the that is not considered as a crime, so with a dangerous electricial item dropping tails would be permitted.

Clearly tails can be reconnected, but it would need a tool or key, so can't see simply switching off would be permitted under HSE rules. One needs to disconnect in a way a tool is required to reconnect.

Any electrician who awards a code C1 without making safe is crazy, and asking to be taken to court should anyone get injured.

ericmark said:

There is an allowance for a cable reasonable protected from damage to be protected at destination as long as not branches and under 3 meters long. Many feel that does not apply to a ring final, however this is up to the inspector.

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Please don't keep bringing up this. You are misreading the regulations.

The three metres limit only applies where there is no fault protection, in which case it must also have fire protection.

ericmark said:

There is an allowance for a cable reasonable protected from damage to be protected at destination as long as not branches and under 3 meters long. Many feel that does not apply to a ring final, however this is up to the inspector.

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As EFLI has said, that is not correct.

In any event, you are talking about situations in which it is allowed for (required) overload protection to be provided downstream of the cable being protected. What we have been talking about is a different regulation, in relation to situations in which overload protection is not required at all.

ericmark said:

Yes you can't turn or lock off a dangerous supply without authorisation however you can't test without turning off, and clearly if faulty you can't turn it back on.

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Were it just a question of turning back on a Main Switch or other isolator, that would obviously be trivial, since I could deal with the situation myself. However, if, without my authorisation, an inspector 'locked off' my electricity supply in a manner which required me to pay another electrician to restore my supply, I could pursue that inspector through the civil court in an attempt to recover the loss he had caused me to suffer.

ericmark said:

British law says if you break the law to stop a greater crime the that is not considered as a crime, so with a dangerous electricial item dropping tails would be permitted.

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I'm no lawyer, so I don't know if that is true - but, as above, I was thinking about civil remedies, not criminal prosecutions.

ericmark said:

Any electrician who awards a code C1 without making safe is crazy, and asking to be taken to court should anyone get injured.

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I would personally say that "Any electrician who awards a code C1 without offering to do the making safe is crazy...".

Kind Regards, John