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DougP

Does it need to be earthed?

DougP

Your reference to single insulation is correct. But the neutral bar in a MEN switchboard is not a live part. 1.4.63

DougP

It's not unusual to get UG mains inspected before the trench is filled.
Or if you're trusted by the inspector, photos proving the depth and protection/marker strip are installed would be acceptable.

DougP

Isn't that referring to the solar supply main switch? So it's just a CB rated appropriately for the inverter?

DougP

Is there a 3012 requirement to have RCD protection though?

DougP

Distributed gas - is piped cooking/heating gas - eg. LPG etc. So not A/C systems.
Same with water. Only applies to distributed water supplies. Not sewerage or stormwater.

For those other services, 3.9.8.4(a) would apply. And 3.11.5 for underground.

DougP

Agreed. I'm not sure why there seemed to be so many hearing decisions released at once, or why the change to link the full document. Maybe it was always there, and I never looked. And yes, if someone had time to analyse every investigation and decision, I'm sure that there would be many shortcomings...

DougP

Does 4.8.2.3 apply to a spa pool because it is an appliance producing hot water or steam?

DougP

Thanks for the reply Alec, This is the link to the case. https://www.ewrb.govt.nz/assets/documents/complaints/walters-2020-ce22193-final-decision.pdf My point with not requiring the sign is exactly the same as amended in 3000:2018A1, they have removed the requirement for the sign where the lights ar...

DougP

I see that further down in the decision: "The Board found that the Respondent had not committed a disciplinary offence with regard to installing a socket outlet using wiring of a cross sectional area less than 2.5mm2 as it noted there was appropriate protection and, as such, the socket was compliant...

DougP

So the person was charged with replacing a shaver outlet on a 1mm2 cable (10A MCB) with an RCD outlet. Not compliant with 3.5.1 and table 3.3. Of course there is no mention of the exception to that clause? They also mention that the 1mm2 was "completely covered in thermal insulation". Firstly, that ...

DougP

1. The earth to the power point is not a bonding conductor, so the 4mm2 minimum doesn't apply. The bonding conductor can connect to the circuit earth, in order to be connected to the installation earthing system. The 4mm2 minimum is more about mechanical strength, than CCC or resistance. The clauses...

DougP

Yes, bonding the starter bar should be fine. You can test the resistance to other parts of the reinforcing with your low-ohm meter to make sure it's working. Maybe you need to connect to a couple of points. The connection to the bar does not need to be accessible. You should obviously try and make i...

DougP

But if the MEC is obvious at the MSB, then disconnecting it a doing a loop test to it will prove that it does go somewhere. I would expect somewhere between about 20-60ohms on average. Sometime less, sometimes more - up to about 150ohms possibly. If you get less than 5 ohms, I would suspect it's con...

DougP

A compressor is not a medium or high risk product so an SDoC isn't required. And even if it was, the SDoC is only required if the product is going to be sold. Is the client intending on selling the compressor? As for certifying the work on the appliance, COCs or ESCs only apply to work on installati...

DougP

The 2000 version of 3000 was the first time that there was a note regarding reaching across the open surface to operate the switch. Being a note, it is only advice. The clause is basically the same in the current 2007A2 version. 3000:2018 is the first time there is now a restricted location of the s...

DougP

Looks like maybe the last 3-4 days of posts are gone?

DougP

---- (3) An RCD used to protect against electric shock, and that is either installed as part of an installation or is a portable RCD, is deemed to be electrically unsafe if it has a rated residual current exceeding 30 milliamperes and— (a) it does not interrupt the current in all live conductors wit...

DougP

Thanks. Yes I thought it was probably fine. Similar to a transportable switchboard with only one RCBO.
Good to get a second opinion though

DougP

Hypothetical.. If there was a main switchboard on a pole near the property boundary (configured correctly as a MSB), and the only outgoing circuit was a submain to a house, can the submain protective device also be the main switch? In other words, there is only one 63A circuit breaker on the switchb...

DougP

If it's just behind an appliance cover, like a rangehood cowl, then it's not really inaccessible, you just have to remove a cover to get to it. So it is possible to "access" it, as per ESR20(2)(i).

DougP

Don't forget to calculate voltage drop. You haven't mentioned distances in your post, but for 20 units, there must be a reasonable length on some of them.

DougP

I have one o these Mastech ones. Cheap, but it has got me out of trouble a few times.

DougP

Nathan, Circuit breakers are suitable for isolation as they will all comply with AS/NZS60898.1 (AKA IEC 60898-1).
They should also be marked with the symbol in the clause that Pluto indicated, which confirms they are suitable for isolation.

DougP

B(i) includes "Permanently connected electrical equipment not exceeding 10 A and not included in other load groups"

How is the strip heater not included in group D?

And would B(i) also apply to an airconditioner less than 10A?

DougP

Maybe check this topic.

https://electricalforum.nz/viewtopic.php?f=5&p=696#p696

DougP

I'm pretty sure that every appliance must have a label stating the rated voltage and power consumption at minimum. It should also have markings for any other rating that are applicable, like double insulation, or IP rating.

DougP

As Jamie said, the 2.5mm² earth is fine for that submain.

But why not just run a 32A circuit and connect both?
Or just run two 2.5mm² circuits? Depending on the length to check the voltage drop.

DougP

This one is about a metre high. There's basically nothing available off the shelf in NZ, so custom made is probably the only option. This one is in a high wind zone, and the mains go up to the pole which is about 10m height difference, so it has a stainless backstay wire and fixed stay as well. Cust...

DougP

And just one other point to consider. As Alec said, the main switch in the outdoor "main switchboard" must be readily accessible. But also, there can't be any primary insulation in the enclosure that is accessible without the use of a tool (to be "readily accessible").

DougP

Elliot said that he fed the circuit breaker for his circuit from the load side of the fuse. I would just assume that he's not an idiot, and that fuse is after the meter, not before it, so that might make it a protective device for a submain. (Normally though, his circuit breaker should have be conne...

DougP

That's probably right.
Where it is now, doesn't comply with the current rules either, but it will be allowed to remain (as long as it complied with the rules when it was built - which it probably did).

But if you change anything, it will have to comply with the current rules.

DougP

If the MEN is at the "meter board", and there's a main switch there as well, and there is a neutral bar and an earth connection, and the main earth conductor is connected to that earth connection, and there is outgoing circuit protective devices (you said 63A fuse for the other switchboard) - then t...

DougP

There is no hazardous area around a califont. So as long as you don't go into the other areas you mentioned, the socket outlet or other equipment can basically go anywhere around it.

DougP

You can have both sharing the same electrode.
There's no requirement for an electrode to be exclusive, only the main earthing conductor and connection to the electrode that needs to be exclusive.

DougP

Hi, Be careful, if the fitting isn't labelled that it can handle a voltage, how can you assume that it can? In New Zealand RCDs are required to be labelled with the voltage they are designed for. If the RCD doesn't say 400, or 230 for that matter, it means you can only assume that the labeling is c...

DougP

Ok, yes that makes sense.

So is there a clarification somewhere else that the conductive enclosure doesn't need to be earthed if the cables are sheathed?

DougP

3.10.3.3 Continuity Mechanical and electrical continuity of conductive enclosures shall be maintained. Exception: Continuity of conductive enclosures need not be maintained where, in accordance with this Standard, the enclosure is not required to be earthed, e.g. the enclosure contains insulated and...

DougP

"for the line side feed to RCDs or RCBOs, the clause doesn't apply." I don't think that's true. I can see nothing that exempts these connections from being required to be identified. This question came up again recently in another forum, regarding a combined A & N busbar being used on the line side...

DougP

If you use them for a 3ph load, then with one or two turned off, it could have up to 400V across it. And I guess technically, if one circuit breaker out of 3 on a 3phase circuit trips, it is breaking to an open circuit voltage of up to 400V. But yes, mostly they are used on single phase circuits, ev...

DougP

May-July Page 18, third column "Cheap 230V MCBs are often used on three phase installations but some electricians don't realise that they could end up with 400V across them" Yes, some "domestic" MCBs are marked as "230V", and some have a little picture of a house on them, but the specifications tell...

DougP

There was only the two sizes used in NZ AFAIK.
7/.036 which was equivalent to 4mm2.
And 7/.044 which was closer to 6.5mm2

If you've looked at the ratings in appendix I, then you'll have a pretty good idea.

DougP

Wiring in a switchboard is rated as unenclosed in air. So you would use the rating from 3008 table 4. The rating of 10mm² is 79A in table 4 column 2 - (or 76A if you follow the guidance in table 3(1) and use the table 4 column 5 rating). So it's not really accurate to say that it's just because it's...

DougP

Yes, if it is plugged in, and comes under 3001, then all final subcircuits must be RCD protected.
Along with the current limiting required to match the supply lead rating, the "switchboard" can be as simple as just one 16A RCBO to protect all FSCs in the transportable.

DougP

I hope the question is helpful in re-fashioning some additional clarity into the clause.. because in my view, 8.3.5.2 (a) and (b) are quite clearly only talking about the PEC. The first sentence "The resistance of protective earthing conductors shall be:" says to me, that the result must be only the...

DougP

Thanks for the detailed reply as always Alec

DougP

Yes I understand and agree with all those points. The argument quite simply, was about whether Re needed to be determined in its own right, or getting the correct Rphe reading was sufficient. My point was, that because of the mixture of cable sizes, it would be impossible to calculate Re from the Rp...

DougP

@Alec - yes the situation in question was non-residential and didn't have RCDs. So a loop test was required for socket outlets, at the appropriate stage in the testing. Similarly, in the other thread, people were referring to the EFLI testing, and A-E loop, and concentrating their responses to socke...

DougP

This is a (part) post from someone on another forum. -------------- Remove the active and the earth from their respective terminals and link with a wago. At each point of connection measure the resistance of active and earth with my 1825 mtf with the plug adapter. I should get a gradually increasing...

DougP

Part of the outcome of this test, is to: "ensure that the earthing system has been installed in a manner that will cause circuit protective devices to operate if there is a fault between live parts, other than the neutral, and the mass of earth" Can this be satisfied by measuring Rphe and confirming...

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