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Posted By Topic: 110v Sockets

Nov 08 2018 16:16

WE have a client that has a couple of pieces of 110V equipment that he would like to use in his house.
Can we install a 230-110v stepdown transformer in his garage and use that to supply a couple of 110v Sockets in his house.
I believe we are not allowed but have been unable to find the relevant references in the regulations and AS/NZS3000



Nov 08 2018 16:45

you would a require a 110V socket that has attained a NZ SDoC, I believe Legrand have one in their Arteor range that has this. As it is a different outlet style it should be legal, but it would pay to label them some how 110V 60Hz etc.

Nov 08 2018 16:53

I don’t believe that there will be a prohibition on doing this but there are several things that you have to get around.
The first thing is that domestic installations have to be done to comply with AS/NZS3000:2007 Part 2.

This means that the socket outlets will have to be RCD protected. Hard to achieve after an isolating transformer.

Most 110 volt equipment comes from the USA and is designed to operate at 60hz. Motors will run slower and draw more current. Cooling fans will possibly not move as much air as required.

Appliances that do not comply with one of the standards cited in Schedule 4 of the Electical (Safety) Regulations 2010 are by definition unsafe. ESR23. It is unlikely that 110V appliances will comply with any of the cited standards.

So despite there being no rule specifically saying No the things you have to get sorted are many.

Nov 08 2018 17:44

The other thing most small transformers can\'t do is supply sufficient fault current to operate fault protection by automatic disconnection. Could use an RCD on the output, but won\'t find one that\'s been Approved as a DHRA and operates on 110 V.

There are new additional rules specifically for non-standard socket types in the 2018 edition of \"3000\" []. Basically only allowed in international airports & hotels; and if at 110 V have to be supplied at \"reduced low voltage\". True the new edition has yet to be cited, but you\'d be brave / foolish to ignore what it\'s telling you.


Nov 09 2018 15:16

> There are new additional rules specifically for non-standard
> socket types in the 2018 edition

That\'s just mean.

Of course, the right answer is to use sockets according to IEC 60309 a/k/a ceeform.

Conversion from ceeform to USA is left as an exercise for the homeowner.


Nov 15 2018 11:48

maybe mean, maybe not.
Whichever, the NZ-only bits of this new clause are direct from Energy Safety so better get used to them.

Dec 10 2018 15:34

So even though gives allowance for's pointless as:

A) you can not install US type sockets as no one can sell them. An SDoC issue

B) if on a step down transformer (which it most likely will be) you can't find and RCD/RCBO cleared for sale in those bounds here either.

US single phase is 120V anyway, so reduced low voltage is not required. Not that that is any great result to this problem.

I'd just like to know why is even a thing if it's not possible to install sockets from these countries. As finding one with an SDoC is impossible. Is there an international standard recognised as a suitable reference in substitute the need of a SDoC? Doubt it.

Dec 10 2018 15:54

typo:last line was supposed to be

Dec 10 2018 16:17

FPG01 your point a) is not true as stated above Legrand have one with a NZ SDoC. Along with a few others.

Dec 10 2018 16:18

IEC 60309-2 has 110 volt socket outlets which complies and will be made of Yellow plastic.

You have to remember motor operated equipment the motor will run slower and likely to burnout after a short period of operation due to low cooling of the motor.

Use a Reduced low voltsge supply (55 volts to earth).

Actually a secondary is a 110 volt winding with a centre tap earth AND must be an isolated from the primarly (230 volts) and only earthed by the centre tap. No need for a RCD at all.

Look in ESR 2010 regulation 89 (2) (d) for the conditions of use for 55 volts of earth.

Dec 10 2018 16:32

Point B not entirely true either; there's nothing to stop a supplier from getting an Approval and issuing an SDoC (mcbs & RCDs being DHRAs asw ell as DMRAs) if there was enough demand to make it worth their while.

The reason the clause exists is to
a) provide clarity that up to now has been missing; and
b) impose enough restrictions to ensure safe operation; and
c)the extra NZ bits prevent people from doing what the OP's customer wanted.
Remembering it's a joint Standard so the first half of the clause applies on Oz as well as NZ.

What ES really DON'T want is people using travel adaptors.

Item a) of the new clause may be a bit late; there are already multi-fit sockets that have been installed (illegally?) in hotels in NZ.

Dec 10 2018 16:55

I am not strictly saying that these points are in stone and insurmountable but I know from looking into a very similar scenario that currently you are not able to get this done. My points I suppose are just relevant to this point in time.

I would have to look at the Arteor model but I can not tell you how many suppliers turned me down for sale similar products. Same with MCBs and RCDs. These obviously exist outside of NZ and yes could easily pass all requirements to get an SDoC....if there was the high demand. But that is the issue. There is no such high demand. I asked that question too. No one wanted any part of it.

As US voltage is actually 120v not 110V. Having the center tapped 110V transformer is not appropriate. Though it may depend on the strictness of your client's requirements (which mine was). Many of the yellow sockets are also just rated for 110V.