Help! What electrical certificates do I need?

[securespark]

Where?

 

[Risteard]

612.3.1

 

[JohnW2]

612.3.1

That no longer exists. Indeed, none of Chapter 61 exists any more. I suspect that you might me talking about ....

643.3.1 The insulation resistance shall be measured between live conductors and between live conductors and the protective conductor connected to the earthing arrangement.

If so, I would take "the earthing arrangement" to refer to the installation's CPC system, including MET, whether or not that was connected to actual 'earth'.

After all, although I realise that some 'requirements' of the regs are seemingly rather daft (and that some people feel constrained to comply with daft regulations), there is no electrical reason I can think of for requiring anything to be 'earthed' during IR testing - which is probably why I have never really interpreted the above to be imposing such a 'requirement'.

 

[John D v2.0]

Not sure about the confusion, it wouldn't be a proper test if the cpc want connected to the earthing and bonding.
if there was a fault between a live conductor and some metalwork in the house with a path to the main earth as the MCB or RCD would go as soon as the circuit was energised.
Of course one could do all the tests with the cpc not connected and then do separate ones from live conductors to the MET but that would be extra work.

 

[JohnW2]

Not sure about the confusion, it wouldn't be a proper test if the cpc want connected to the earthing and bonding. ... if there was a fault between a live conductor and some metalwork in the house with a path to the main earth as the MCB or RCD would go as soon as the circuit was energised.

Since you mention confusion, I have to say that I'm a bit confused by (uncertain of) what you are saying there (in relation to IR testing). Could you perhaps clarify?

Of course one could do all the tests with the cpc not connected and then do separate ones from live conductors to the MET but that would be extra work.

'Not connected' to what? I don't think there has ever been any suggestion that CPCs (if present) wouldn't be connected to the MET - Risteard's assertion appears to be that having CPCs/MET connected to ('true') earth is a "fundamental requirement" for IR testing.

Kind Regards, John

 

[John D v2.0]

Well if there wasn't a true earth connected to the MET, what would happen if a live conductor was sitting in a puddle under the house.
Unlikely on a new circuit just installed, but true earth is something that should probably be connected for the IR test.

 

[JohnW2]

Well if there wasn't a true earth connected to the MET, what would happen if a live conductor was sitting in a puddle under the house. Unlikely on a new circuit just installed, but true earth is something that should probably be connected for the IR test.

Fair enough. I have to concede that you have identified one type of situation in which an IR test 'to earth' (rather than 'to CPCs') would theoretically be required.

I would, however, say that what you suggest would probably be an incredibly unlikely/uncommon situation - since it would require not only that a live conductor be in a puddle which was in contact with 'the earth', but also that the conductor would have lost some of its insulation and also that an associated CPC was not in any way involved (in the puddle). I suppose that almost nothing is impossible, but I'm having to try pretty hard to think of how such a situation could arise!

Of course, other than in the context of this thread, the question under discussion is most unlikley to ever arise, since one would never normally be even contemplating IR testing in an installations whose CPCs/MET were not connected to some sort of earth.

Kind Regards, John

 

[Risteard]

That no longer exists. Indeed, none of Chapter 61 exists any more. I suspect that you might me talking about ....

If so, I would take "the earthing arrangement" to refer to the installation's CPC system, including MET, whether or not that was connected to actual 'earth'.

After all, although I realise that some 'requirements' of the regs are seemingly rather daft (and that some people feel constrained to comply with daft regulations), there is no electrical reason I can think of for requiring anything to be 'earthed' during IR testing - which is probably why I have never really interpreted the above to be imposing such a 'requirement'.

Yes, sorry it's been renumbered. Earthing arrangement is not open to interpretation. It clearly requires the Earthing conductor to be connected during the test. The reasons are fairly obvious too, and cannot be considered anything other than an eminently sensible requirement.

 

[johnny2007]

I'm not an electrician but in a property I refurbished the spark disappeared and another one came on the scene.
He fixed all the bodge of the previous one, tested the whole lot and issued the landlord with a certificate of compliance (I'm sure that's how it called it).
So shouldn't an electrician be fixing the faults, testing the system and then certify that it's safe despite not being entirely new?

 

[JohnW2]

Yes, sorry it's been renumbered.

Fair enough, but if you are going to post references which consis of just a reference number, without any explanation, one might hope that you would ensure that the number was correct in terms of current regulations.

...It clearly requires the Earthing conductor to be connected during the test. The reasons are fairly obvious too, and cannot be considered anything other than an eminently sensible requirement.

Following John's post, I have have agreed that it would make a difference in an extremely improbable set of circumstances, but I have to say that I have yet to think of a way in which the situation could/would actually arise in the real world. As I've said, it would only happen if (all layers of) the insulation of a live conductor were somehow compromised, if that compromised insulation resulted in an electrical path to 'true earth' (e.g. wet soil - but not a bonded extraneous-c-p) and that no associated CPC, armour, metallic sheathing etc. was also involved in this fault. Even deliberately engineering such a situation would be far from simple.

In any event, as I've said, it's almost a hypothetical discussion since (despite this thread), installations with no earth are very uncommon and, even when they are occasionally encountered, it's very unlikely that anyone would contemplate IR testing before addressing the earthing issue.

 

[JohnW2]

I'm not an electrician but in a property I refurbished the spark disappeared and another one came on the scene. He fixed all the bodge of the previous one, tested the whole lot and issued the landlord with a certificate of compliance (I'm sure that's how it called it).

I think that either he or you have probably got the terminology a bit wrong. As I understand it, only local authorities can issue "Compliance Certificates".

So shouldn't an electrician be fixing the faults, testing the system and then certify that it's safe despite not being entirely new?

An electrician can certify all the work he/she has done (e.g. 'fixing faults'), including relevant testing. An electrician can also undertake an Electrical Installation Condition Report (EICR), which involves inspecting and testing all/most of the installation and issuing a report on the current state of the installation (including recommendations for any remedial work which is either required or 'recommended').

Kind Regards, John

 

[Risteard]

Fair enough, but if you are going to post references which consis of just a reference number, without any explanation, one might hope that you would ensure that the number was correct in terms of current regulations.
Following John's post, I have have agreed that it would make a difference in an extremely improbable set of circumstances, but I have to say that I have yet to think of a way in which the situation could/would actually arise in the real world. As I've said, it would only happen if (all layers of) the insulation of a live conductor were somehow compromised, if that compromised insulation resulted in an electrical path to 'true earth' (e.g. wet soil - but not a bonded extraneous-c-p) and that no associated CPC, armour, metallic sheathing etc. was also involved in this fault. Even deliberately engineering such a situation would be far from simple.

In any event, as I've said, it's almost a hypothetical discussion since (despite this thread), installations with no earth are very uncommon and, even when they are occasionally encountered, it's very unlikely that anyone would contemplate IR testing before addressing the earthing issue.

In fairness I was asked for a Regulation number when I hadn't a copy of the Regs book on me. I don't carry it round with me.

 

[DetlefSchmitz]

In fairness I was asked for a Regulation number when I hadn't a copy of the Regs book on me. I don't carry it round with me.

I thought you said you didn't have one because you couldn't afford it.
I was surprised though, because most of the 'schemes' require you to possess an up-to-date copy.

 

[EFLImpudence]

As I understand it, only local authorities can issue "Compliance Certificates".

Wrong way round:
Schemes - Compliance.
LA - Completion.

 

[JohnW2]

I thought you said you didn't have one because you couldn't afford it.

I think that was in relation to BS 7288 (in another thread).

Kind Regards, John