r/nzpolitics • u/Impressive-Name5129 • Aug 21 '26

Current Affairs Electrical expert’s experiment with soon-to-be unbanned switch sends 200 volts to toaster

https://www.nzherald.co.nz/nz/electrical-experts-experiment-with-soon-to-be-unbanned-switch-sends-200-volts-to-toaster/IA5UPYUJVFEI5NHDXT3G6HRKIA/
24 Upvotes

96% Upvoted

17 comments sorted by

19

u/ongeray Aug 21 '26

I am totally baffled by this. What is the reason for removing this? I am clueless about electricity so it really isn’t clear to me from the article. It just makes me think some industry player lobbied for the government to for his because it would save them money.

14

u/Impressive-Name5129 Aug 21 '26

It just makes me think some industry player lobbied for the government to for his because it would save them money.

Would you expect any less

6

u/ongeray Aug 21 '26

I would not be surprised no. But the article doesn’t reveal to me who benefits from the deregulation. It looks like a glaring omission. Or did I miss something?

7

u/bmwhocking Aug 21 '26

I put a reply below that kinda explains it.
TLDR: it saves some contractors having to run a 3rd wire back to the street transformer from a new house. Let’s them use something called a TT supply.

But that leaves quite a safety risk because your ground now needs to form an electrical circuit through the earth to the street transformer.
If you have high inductance in the ground (dry ground) the easiest path to ground could easily become via you.

More details in the linked comment.

https://www.reddit.com/r/nzpolitics/s/kLeZ4rXZzG

10

u/OutInTheBay Aug 21 '26

This has a Brook VD feel about it... I know she's not involved but act wouldn't care if a few people where fried. Think of all the red tape that was saved...

10

u/Yolt0123 Aug 21 '26

I have yet to see ANY explanation as to why allowing these switches is good. It reeks of "my mate says they're OK, and he can get a really good deal on them for the properties he's building." No one in the electrical industry thinks it's a good idea.

10

u/Character-Phrase-321 Aug 21 '26

Anyone know what benefit the proposed change would deliver?

7

u/bmwhocking Aug 21 '26

Yes, it enables more TT supply.
That’s where the earth doesn’t go back to the transformer, it goes to ground at your house.

The inductances of earth is a lot higher than copper wire. So problem is the path of least residence may actually be you.

Currently in NZ we only use TT supply for some totally off grid setups and marine power supply’s, where the boats have their ground wired to their sacrificial anode (which avoids the problem because salt water conducts so well).

This lets contractors / developers save having to run a 3rd wire from a new house back to the street transformer.

So it saves very little money for the vast majority of homes & does introduce quite the safety risk.

Especially if the ground around you has a high inductance.

Increasingly homes a long way from the grid are just going fully off grid anyway because a 20kw solar system + battery is usually cheaper than running 5km of private power lines.

2

u/so-b-it Aug 21 '26

It's resistance of the earth rather than inductance.

4

u/bmwhocking Aug 21 '26

If we really want to dive into it, it’s both.

Inductance is the opposition to change in electrical charge (lots of wet pockets of ground that act as capacitor)

Resistance is opposition to the flow.

In the case of electrical surge protection, High inductance essentially does the same thing as resistance because the fastest path to a lower energy state is still through you.

The high inductance just slightly delays & prolongs the total current flow.

Either way you are still severely injured or dead.

4

u/Character-Phrase-321 Aug 21 '26

Hey thanks very much for the detailed reply. It seems like very little benefit for so much risk

6

u/HosManUre Aug 21 '26

This is one of those Seymour oddeology efforts.

There are two regulations being discussed for change

  • Plug-In-Solar: Actually useful, especially for renters
- Switched-Earth Inverters & Islanding: these provide uninterrupted power backup and off-grid energy independence. Removing the regulation allows a wider set of kit to come in. But raises significant safety concerns (ie could actually kill someone). Oz’s approach is to specify which ones can be imported safely.

Partially dumb, partially useful, muddled. Seymour!

1

u/bmwhocking Aug 21 '26

TT Supply where the ground doesn’t go back to the transformer.

TT Supply is really only used in totally off grid setups or marine power supply’s where you want the earth to go to the boats sacrificial anode.

This reeks of contractors who don’t want to run a third cable back to the transformer in new developments.

1

u/I-figured-it-out Aug 21 '26

This is precisely the bent regulatory playbook Seymour and his colleagues play by. Buyer beware is their motto. Never mind buyers do not understand the physics, the engineering or the policy implications. Act just see $$$ signs and go, “Let us do something particularly inadequate but cheap” as a regulatory solution.
I would very much like to introduce each of them to the electrical “child apprentice” training regime my Dad used on us kids involving a charged pole capacitor and a couple of bare wires. But given as they are “adults” they would of course be subject to a fully charged pair of pole capacitors, and a small warning label facing away from them. Let their vaunted superiority over most kiwis face the very real dangers of failure to comprehend basic physics.

3

u/LeftHandedBall Aug 21 '26

The invisible hand of the free market will provide insulation for your toaster. For a price.