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DougP

@AlecK Maybe thinking about it this way? 400V phase to phase for primary. 230V phase to phase for secondary 115V phase to neutral secondary Yes, the fault protection needs to be correct. But for the unbalanced secondary load, it will be 115V load which was unbalanced, and having a secondary neutral ...

DougP

If I was wrongly disciplined through an error or misinterpretation of the rules on their part, I would certainly be appealing the decision. I know a couple of people who would probably love to be expert witnesses ;) Also I would hope that all costs would be awarded if successful. Does anyone know of...

DougP

Just looking through the new requirements for "likely to be disturbed" in 3000:2018A2. 3.9.3.3.1 & .2 specify certain locations, but excludes the use of RCDs and points to 3.3.2.6 for mechanical protection. Without a more detailed explanation of areas that are "likely to be disturbed", anywhere in a...

DougP

Worth noting that while in this case such an expert prepared a report; they have not published it. In this case, the expert assisting the investigator was an inspector. And somehow managed to complete a report as a basis for the charges, without visiting the site. The investigator must have taken a...

DougP

Yes, like this. But that doesn't mean that the input side needs to have a neutral connected. As long as any unbalanced loads (single phase loads) on the output have a neutral connected, the output voltage will still be balanced.

DougP

JamieP wrote: ↑
Sat Aug 28, 2021 3:30 pm
Sorry mate, I don't under what you're asking

Maybe he's looking for an instruction book on the processes.

What do we think would be a reasonable charge for such a document?

DougP

That's pretty much what I thought as well.

DougP

Following up with further board decisions. A question came up recently regarding a light fitting having a switch installed in the installation wiring. So for example, if a fitting has a built in switch, is an additional switch required. Similarly, I have done sensor light circuits on rental properti...

DougP

Along the same lines for inspection of mains work - if an installation is using a strip-type earth electrode which in NZ is required to be 7.5m long an buried at 0.5m or more. Is this something that inspectors should be inspecting? With a driven electrode, you can reasonably assume that it is the co...

DougP

If it's going to be plug in, then it's 3001 for the container wiring and the supply to the socket outlet it's connected to. If you hard wire it, then it's not. If it was me, I would weld simple brackets inside to fix conduit onto (or possibly cable tray). The same as is done in steel/aluminium boats.

DougP

But in a simple case of someone running a cable for a socket outlet, they must sight the COC before they connect it.
There is a requirement that the COC is issued before connection right?
So that's the offence.

DougP

Except that ESR73A(1)(c) requires the COC to be issued before the installation or part installation is connected to a supply.
So issuing the COC any time after the work is connected (other than for testing), must be an offence under 73B right?

DougP

3000:2007A2 Figure 6.7 doesn't match fig 6.8, fig 6.9, or the wording of 6.2.2.1 I know AlecK has explained the string method of determining the zones, but that doesn't prevent zone2 still existing on the other side of a 1.8m screen/barrier because zone 2 is 2.25m high. This doesn't seem to have cha...

DougP

So for example, if there was a sub board with 2 FSCs, you're asking if there should be 2 RCDs? Because there might already be one or more RCDs on the MSB... I'm not even sure that the note explains it in a helpful way. If there was 2 FCSs, 1 for socket outlets and 1 for lights, having 2 RCDs isn't g...

DougP

Thanks for your comments AlecK I thought I saw something about a review of 3010. Is that still open for comments? There's quite a few questions in other forums about generator supplies. This 3ph supply and single phase changeover switch question is a common one, and also generator supplies connected...

DougP

Sorry Alec, I think I have to disagree. 7.3.8.1.2 seems very specific. "The changeover device shall open all active conductors of the normal supply when the alternative supply is connected." You usually say to look at the words that aren't written, as well as what is written. And in 3010 2.7.2(b) Ac...

DougP

For example, wiring a single phase generator inlet to a 3 phase installation. --- Can a single phase changeover switch (two pole changeover) installed after the 3ph main switch, be used on only one phase to supply that phase from the generator? I'm saying no, because section 7 of 3000 and 3010 both ...

DougP

Size the mains to suit the load, distance and installation conditions as usual. If the cable needs to be smaller for the meter, then just reduce it in the metering enclosure/switchboard. You would need to check your local network rules or retailer rules to get the exact determination. I'm pretty sur...

DougP

Sounds interesting. AlecK is probably all over this

DougP

Around the 60's and 70's, it was common to wire like that when only two outlets were allowed per circuit on a rewirable fuse. When anyone has added to an (old) existing circuit like this in the past, the rewirable fuse should have replaced with a circuit breaker (to allow more than 2 outlets), but o...

DougP

You need to confirm an earth is connected before you can do a live loop test. Which is why there is a specific order of carrying out tests in section 8.
Do the trailing lead Re test first. Then also an IR test would be useful, but the results might be confusing if you don't know how to interpret them.

DougP

Sorry I missed that it was only one outlet. So that circuit probably doesn't have the earth connected correctly. You need to test the earth at the outlet with a trailing lead and a low-ohm meter (not a multimeter).

DougP

I would be checking if it has a MEN link.

DougP

Oh, and yes, the polarity layout is backwards on US outlets (earth, neutral and "hot" - clockwise), but they consider 240V outlets are two "hot" connections (being usually part of a split phase 180deg domestic connection), so they don't really have a polarity AFAIK. Usually I find it easier not to t...

DougP

The Nema L6 series is for 230/240V
They aren't interchangeable with L5

https://diy.stackexchange.com/questions ... connect-to

DougP

The editable PDFs are what I use. The only issue is that if you send that PDF to a client, it is still editable - so any details could be changed. The way I am getting around that, is to print it to another PDF document, which then isn't editable. Maybe there's a way to lock or password protect the ...

DougP

This is what I picked as the important parts that make it a main switchboard, rather than just a meter box. (NOTE: these clause numbers are from 3000:2018 because I made the list for an Australian group - but the same requirements are in 3000:2007) -------------------- Firstly, it must actually be a...

DougP

the first paragraph in 5.6.2.6.4 isn't written clearly. ".. for the bonding connection to be made to the conductive parts of the pool structure" Sounds like the connection point should be on the conductive parts of the pool structure. I don't think that was the intention. The rewritten clause in 300...

DougP

3000:2018 has a 30deg angle zone under an overhang, where no IP rating is required. Cleaning/waterblasting isn't taken into consideration.
3000:2018A1 4.1.3 & Fig 4.1

DougP

It can just be an enclosure with an earth bar. Mounting it near the pool equipment power point(s). There is a dedicated enclosure available (in Aust at least). But because the connection to the reinforcing doesn't need to be accessible, I wouldn't bother using anything like this. https://www.conduct...

DougP

The current ratings for conductors in switchboards is unenclosed in air. Normal PVC cable ratings are 3008 table 4.
So the rating of 6mm² would be 58A @ 75deg.

Almost all conductors these days are V90, so exceeding the 75deg rating is possible, and that would take the rating up to 67A.

DougP

Everyone knows how to terminate a junction box don't they?

DougP

Have a look at 5.6.3.2(b) exception. The bonding conductor can just be the earth in the supply cable to the pump or other equipment.

DougP

3.12.1 specifies the allowable types of conductors. They don't have to be hard drawn. The first item on table 3.9 is annealed copper conductors.

DougP

There seems to be some confusion between aerials and catenary?

DougP

I was under the impression that cable manufacturers recommended that their cables were protected from UV. But on re-reading their information, I see that they mean the insulation of the single cores, and that the sheath provides the UV protection. I've noticed that lines companies are also sleeving ...

DougP

send it to covs@trustpower.co.nz

DougP

You should be able to find 6mm2 twin NS cable? I have used it before, although it might have been the underground variety. The other option is to use TPS in a conduit on a catenary (4.13), or build a solid structure between the buildings if they are close. If you build a structure, then the minimum ...

DougP

JamieP wrote: ↑
Fri Jan 29, 2021 10:13 am
Or attempt calculation 5.3.3.1.3 and see what happens haha

ain't nobody got time for that

DougP

IMO, according to the wording of "the largest active conductor of the consumers mains", you should go for the earth rated for the size of the 120mm² Al. The 50mm² Cu, only has a suitable CCC for that service because it's rated as spaced within a switchboard. It's not big enough for the whole mains r...

DougP

Starting current or overload current (locked rotor, over pressure etc) , isn't usually allowed for in installation wiring. Such as the note in 3.6.2 for example. But also the wiring and protective devices have to work in the real world. So for example (without getting into the technicalities of soft...

DougP

An appliance that isn't faulty being plugged in shouldn't give you a failed reading, because you only test from each of A & N to earth. So presumably you were checking between A & N? That isn't a required test. It's probably debatable how much testing should be done when replacing a switchboard, but...

DougP

That's my thoughts as well.
But some in the trade think that everything in the MIs override 3000.

DougP

Under 3000:2018, which presumably NZ will eventually cite, sections 2, 3 & 4 of the book has a new paragraph at the beginning. --- Installed in accordance with the requirements of this Section, and the additional requirements as specified in the manufacturer’s instructions. --- If an induction hob h...

DougP

Merry Christmas everyone!

Here's a brain teaser for you...

PEN submain to a switchboard in a pool shed?
Yes or No?

DougP

How do you plan on inspecting the installation of the mains? Do you have a spade in the truck?

DougP

If the actives of the supply to the second enclosure, comes directly from line side actives in the first enclosure, then the supply to the second enclosure is not a submain. 1.4.89 - submains. (in part) .... "...at the load terminals of the circuit protective devices provided within or on a switchbo...

DougP

3.3.2.6 in the 2018 version is the same as the 2007 version apart from the title of the clause.
The asterix is because the name of the clause changed from "impact" to "mechanical damage.
Appendix H was already in the 2017 version.

DougP

No. Why do you ask?

DougP

for double insulated conductors no, but for good practice yes, the photo is a good example That's not going to help the guy on the forklift if he gets off it when the forklift is live though. The cables were only damaged on the forklift side, not the back. And any electrical worker getting up there...

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