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Posted By Topic: Switchboard replacement

Nickg
Feb 27 2019 16:07

Is a MEN switchboard replacement 'low risk', or 'high risk'? Say for example and old asbestos panel switch board replaced with a modern one, with no upgrade to mains, or capacity of supply, and not relocated. Just a straight replacement.

I had advice last year from WorkSafe it would be considered 'low risk'. But others seem to think it 'high risk' (mains work).

Thanks
   

EyesEars
Feb 27 2019 16:27

Definitely low risk. But because you are replacing the entire board and I'm guessing old fuses to new you will be required to add RCD's. AS/NZS 3000 2.6.3.4 covers the replacement of all circuit protection.
   

pluto
Feb 27 2019 16:57

Use RCBOs for a easier changeover of the switcjboard and its fittings. Also remember the neutral bar is now considered a live part and must be screened from touch.
   

Nickg
Feb 27 2019 17:32

Understood, the mains work is replacing like for like, and therefore ‘low risk’.

So do you consider RCD installation an alteration to the original, and therefore this part of the switchboard replacement would be ‘general risk’?

I thought there was an exception regarding the neutral bar being a ‘live part’, under the ‘live part’ definition in 3000? Maybe I’m misunderstanding it though.
   

AlecK
Feb 27 2019 17:44

Yes adding RCDs is "general" PEW; requiring a CoC.

True under clause 1.4.63 of "3000" the main N-bar is not classed as a "live part"; but ESR 4((2) gives priority to definitions in the act & ESRs over those in the standard. Which can affect how rules apply.
Also that bit in 1.4.63 is only a Note, so not part of the definition and not an Exception to it; only an explanation.

In this case not a biggie; since all modern style swbd enclosures keep the N-bar inside and so covered.
   

gregmcc
Feb 27 2019 18:22

Replacing the switchboard would fall in to the high risk mains area.

from the EWRB web site

https://toolbox.ewrb.govt.nz/home/is-this-high-risk-work/

any work on the MEN link (except for testing) makes it mains work, same for disconnecting/reconnecting main earth and main neutral.

Best idea is to get it inspected so you are covering yourself.

   

Someone
Feb 27 2019 18:45

Except that, from your very own link (and more clearly Reg 6A), PEW is only high risk if it is not low risk.

That is, if it meets the criteria to be both low & high risk, low risk wins.

So the question is whether this constitutes "the maintenance or re-
placement of a fitting in an existing installation".
   

Nickg
Feb 27 2019 18:54

Yeah I’m definitely thinking low risk. That article does say ‘replacing fittings on existing mains work…is low risk’. I guess just when replacing the entire switchboard, you’re replacing a collection of them at the same time.
   

Sarmajor
Feb 27 2019 20:05

Main Switchboard replacement as low risk work would appear to be the collective opinion but there have been some rather vaguely worded decisions around this from the board.

I too believe that replacement of an entire main switchboard full of fittings is low risk.

But if the switchboard did not have a separate N & E bar with a link then installation of that part of the main earthing system would be high risk.
Also installation of a new earthing electrode and mec where the old main earth was a water pipe would also be in the high risk category
   

AlecK
Feb 28 2019 08:44

+1 Sarmajor

ESR 6A(2) is quite clear: "mains work" can only be classified as high risk if it is not low risk; and ,as per 6A(1), replacement of fittings is always low risk.

I also agree that some of the Board's decisions have been puzzling- especially the one in latest Electrolink.

But Board errors needs a thread all to itself.
Maybe several.