Additions/Alterations

[TPower]

I was having a discussion with another electrician regarding alterations/additions to existing installations, and what exactly are the responsibilities or obligations should you encounter work that doesn't meet current standards?

My attention was drawn to ESR59(3). If for example, you were to replace a fitting on an existing circuit (low-risk work), and you discovered the circuit protection was inadequate for the cable size (perhaps it complied under previous regulations). Is there now a requirement for the circuit protection to be upgraded to meet current standards? Or do we say the part installation is being maintained in it's original condition, as per ESR59(3)(c) and there is no requirement to alter the circuit protection?

If you go a step further, and were not simply replacing a fitting, but extending an existing circuit (general work). Should we now refer to ESR59(3)(a), and the part installation must comply with 3000? Is the part installation the entire circuit, or just the piece you add on? Can you connect a larger cable downstream of a smaller one, and say your piece of work complies, you don't need to upgrade the existing part of the circuit?

My thoughts are that the examples mentioned would still be considered 'electrically safe'. ESR20(1) Electrically unsafe Works/Installations, mentions circuit protection in terms of fault conditions, but not overload.

I'm sure this would've been discussed a lot on the old Electrical Forum, but can't access that anymore unfortunately. Any thoughts, much appreciated!

[Sarmajor]

If you extend a compliant circuit then the whole circuit must comply with the new rules.
Your second to last paragraph pretty much answers your question. It is not acceptable for the finished work to comply with some but not all requirements. Sometimes it is easier to run a new circuit and leave the old (compliant??) work undisturbed.

[JamieP]

I disagree, I feel if you extend a circuit then provided the original section still complies with it's original installation rules it doesn't need to be altered

I believe the part installation is the section you have installed and only said section must be to current rules and regulations the existing section, if unaltered is allowed to remain in service as long as it still complies with the rules it was installed too and as long as it hasn't become electrically unsafe

[PeteRig]

I agree with Jamie, my thoughts are the extended part of the installation must comply with the current rules, for example if you extend a power outlet circuit wired in the 60's, the earth conductors of the time were uninsulated. So if you extend this circuit I dont think you would sleeve the earth conductors of the existing power outlets (only at the outlet you are looping off from), as this cable was compliant at the time but in the 60's for example in a domestic situation the circuit was probably on a porcelain fuse (rule of the time 2 power outlets per fuse) so if you were adding a third outlet to this circuit without upgrading the fuse I believe then it is non compliant. As covered in other posts you can extend an existing power outlet circuit and only required to RCD the new section. Also Loop testing of the new install needs to comply etc.

I suppose this is why 8.4 exists in AS/NZS 3000 so others know when the initial energization of the installation took place, gives sparkies going forward an idea of the rules that should have applied at the time but for alterations/additions after this date if there is no paperwork left on site then there will be no way of telling what rules applied at the time of install, apart from trying to identify the era of the fittings installed possibly but then somebody could have hoarded for example a box of 200 series PDL power outlets and only just installed them now, that would make it confusing.

My thoughts only guys

[DougP]

I agree with Jamie and Pete.
The basic principal applies to the existing part - that if it complied at the time it was installed, it doesn't have to comply with the current rules - unless your additions or alterations are making it no longer compliant or unsafe.

There are various clauses in 3000 that go along with that basic principal - like the RCD requirement only needing to be applied to the additional work, and another new exception in 3000:2018A1 where the allowance in CCC for thermal insulation, even when there is no insulation present, doesn't apply to any existing part of a circuit when extending or altering that circuit.

Of course we should always try to upgrade everything to the current standard whenever possible, otherwise this "complied when installed" will go on ad infinitum and the exceptions will just keep piling up.

[AlecK]

The "part installation" is whatever you describe on your CoC and / or ESC.
Generally that's limited to the bit you've worked on; the fitting(s) you replaced and/or the new fitting(s) you added.
So be careful how you fill in your CoC!

ESR 59(3) applies only to maintenance (including replacement); ie low risk PEW.
So it can't apply when extending an existing circuit.

There's no general requirement to upgrade existing stuff, and ESR 113 covers the principles for "remaining in service".
Similarly only the work you do must comply with current rules under ESR s 59 & 60;
but there's also ESR 13; requiring not only that work done is electrically safe; but also it mustn't make any other part of the installation less safe.
Eg by adding too much extra load to an existing circuit.
For extending a circuit, the ban in using SERFs only applies to the new work; and the existing SERF can continue in service protecting the existing part(s) of the circuit.
But generally it's not practical to apply it this way; the only practical way for the new work to comply is to replace the existing SERF.
And when doing that, we are required to ensure suitability for both existing & new parts of the circuit.

similarly we must consider BTI for the wiring CCC of the new part even if it's not there yet.
For the existing part(s), we need to consider whether it can remain in service as per ESR 113.
Did it comply when installed ? (generally can assume "yes")
Does it still comply with original requirements? (if BTU has been added, maybe not)
Is it electrically unsafe ?
And after that; we must consider the effects of the new work done on the existing parts of the installation
( will the added load take the actual load above the CCC,or create excessive volt drop, etc?).

[TPower]

Thank you for the feed back. Yes, I see I was misreading ESR59. What do the acronyms BTI and BTU mean? I got a bit lost there. Thanks again.

[JamieP]

I think they are both meant to be BTI

And he's referring to building thermal insulation eg batts

[TPower]

Ah yep. That makes sense. Cheers!

[AlecK]

yes both should have been "BTI", as in bulk thermal insulation
(not BTU as in British thermal units)

[Satobsat]

Did a pre-sale assessment on a property, and found new looking lights, switch and 1.0mm² 2C+E tps cable connected to the old 60 series socket circuit, all under the house. Circuit is on a SERF.
Although we are allowed to extend an existing lighting circuit without RCD protection, I think that there should have been an RCD installed protecting this circuit.
As per AS/NZS 3000:2007 2.6.3.4 Alterations, Additions and Repairs Exceptions: The Requirements of Clauses 2.6.3.1 and 2.6.3.2 need not apply to the following: 2 Extensions to final subcircuits supplying lighting points only, provided that the existing final subcircuit is not RCD-protected.

Then there is the fact that it is prohibited to extend a circuit and protect the extension with a SERF nor will the RCD manufacturer allow you to use a SERF to supply an RCD even if one was installed.

Then there is also the fact that the new cables are clipped to Air-Cell foil insulation. It's not like the standard foil it is more like bubble wrap.
Anyone come across this before?
A search shows Kingspan but a different product sold today.

[AlecK]

Agree no adds / alts can be protected by SERF.
Also that all sockets added must gave RCD protection (not necessarily at origin of circuit)
I'm not familiar with that kind of foil; but clearly whoever did this wasn't familiar with the CoP for installing foil near wiring & wiring bear foil.
And with a socket on 1.0 mm2, I suspect wasn't licensed either.

Overall; this needs to be in the report, 'cos who knows what else has been played with.