2 Phase power delivery to homes in NZ. 120-degree or 180-degree phase rotation?

Forums › Home Workshop DIY › 2 Phase power delivery to homes in NZ. 120-degree or 180-degree phase rotation?

billgates

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#302040 24-Oct-2022 16:29

Hi folks,

I am trying to find out the answer for a new Solar PV setup that the Solar inverter company has asked me. Does anyone know if your home has 2-Phase setup in NZ, is it 120-degree or 180-degree phase rotation? The monitoring gear they have works with 120-degree phase rotation but not 180-degree phase rotation.

Do whatever you want to do man.

Mehrts

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#2987353 24-Oct-2022 16:36

Each phase is 120 degrees from each other due to being generated and transmitted in three phases.

Doesn't matter if you have two or three phases that are in use, they'll be 120 degrees apart from each other unless you have something specific on your property that would change that, but you'd already know if that was the case.

Happy to be corrected, but I haven't seen 180 degree phase relationships in NZ before.

richms

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#2987355 24-Oct-2022 16:37

I have not seen 180 used here. Thats just a center tap like they use in the US.

I know it was once used AU where they called it bush power where they only had a single wire feed to whop whop places.

Richard rich.ms

billgates

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#2987356 24-Oct-2022 16:43

Thanks a lot for prompt reply @Mehrts and @richms

Looks like I can proceed with the solar inverter brand and their monitoring hardware then!

Do whatever you want to do man.

Daynger

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#2987449 24-Oct-2022 20:46

billgates:

Hi folks,

I am trying to find out the answer for a new Solar PV setup that the Solar inverter company has asked me. Does anyone know if your home has 2-Phase setup in NZ, is it 120-degree or 180-degree phase rotation? The monitoring gear they have works with 120-degree phase rotation but not 180-degree phase rotation.

You must be buying from offshore?

Surely anyone supplying locally would know how our electricity supply system works, if they didnt i would be very wary about buying stuff off them.

gregmcc

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#2987450 24-Oct-2022 20:52

billgates:

Hi folks,

I am trying to find out the answer for a new Solar PV setup that the Solar inverter company has asked me. Does anyone know if your home has 2-Phase setup in NZ, is it 120-degree or 180-degree phase rotation? The monitoring gear they have works with 120-degree phase rotation but not 180-degree phase rotation.

Generally 2 phase should be 120deg, there is also in NZ 180deg 2 phase that would be 460V phase to phase, but very uncommon.

I can't say I've seen a 2 phase supply, usually either 1 phase or 3 phase, no real reason to supply 2 phase.

You may want to investigate a bit further your actual requirements, maybe some pictures of your meter board and distribution board should throw light on exactly what you have.....

gregmcc

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#2987454 24-Oct-2022 21:05

keep in mind that while solar extra low voltage isn't prescribed electrical work, as soon as an inverter is in the system above extra low voltage (>50VAC or >100VDC) it becomes prescribed electrical work, and the whole solar install becomes high risk that needs inspection. (this includes the extra low voltage solar panels).

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billgates

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#2987464 24-Oct-2022 21:32

Daynger:

You must be buying from offshore?

Surely anyone supplying locally would know how our electricity supply system works, if they didnt i would be very wary about buying stuff off them.

No buying locally but the manufacturer for the product is based out Germany. The support documents only show supporting either single phase or three phase. We have 2 phase at home hence the query to their support team since I am looking at installing an inverter on each phase and whether the single monitoring hardware can manage both inverters coming off two different phases. There is no such thing as as 2 phase in EU. UK is prob the closest country they have for 2 phase and even then, it's exceedingly rare. The support is mixing the 180-degree phase rotation with US which is why they raised a concern about compatibility.

Do whatever you want to do man.

billgates

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#2987466 24-Oct-2022 21:37

gregmcc:

Generally 2 phase should be 120deg, there is also in NZ 180deg 2 phase that would be 460V phase to phase, but very uncommon.

I can't say I've seen a 2 phase supply, usually either 1 phase or 3 phase, no real reason to supply 2 phase.

You may want to investigate a bit further your actual requirements, maybe some pictures of your meter board and distribution board should throw light on exactly what you have.....

gregmcc:

keep in mind that while solar extra low voltage isn't prescribed electrical work, as soon as an inverter is in the system above extra low voltage (>50VAC or >100VDC) it becomes prescribed electrical work, and the whole solar install becomes high risk that needs inspection. (this includes the extra low voltage solar panels).

I will not be doing any electrical work. The Solar PV installer who is an electrician will be doing the work. The setup of the monitoring device is way above an electrician's expertise as it's more IT professional focused but needs to be connected to the mains power.

We do have 2 phase at home. There are quite a few homes in NZ that have 2 phase. Our meter is 3 phase but the number of core's run into the meter are 2 phase. I have counted them myself and the sparky that did the wiring for home build 2 years also confirmed and so did their quote for work. 2 phase current only has the 11kW induction hob connected to it which is why it was run. I did wanted 3 phase but I was talked out of it. I wish I had not listened to the sparky and just asked him to run 3 phase.

Do whatever you want to do man.

Daynger

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#2987980 25-Oct-2022 18:28

gregmcc:

billgates:

Hi folks,

I am trying to find out the answer for a new Solar PV setup that the Solar inverter company has asked me. Does anyone know if your home has 2-Phase setup in NZ, is it 120-degree or 180-degree phase rotation? The monitoring gear they have works with 120-degree phase rotation but not 180-degree phase rotation.

Generally 2 phase should be 120deg, there is also in NZ 180deg 2 phase that would be 460V phase to phase, but very uncommon.

I can't say I've seen a 2 phase supply, usually either 1 phase or 3 phase, no real reason to supply 2 phase.

You may want to investigate a bit further your actual requirements, maybe some pictures of your meter board and distribution board should throw light on exactly what you have.....

Its quite common in larger houses.

Not big enough for 3phase but need more than 1phase.

Scott3

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#2988115 25-Oct-2022 23:09

gregmcc:

...

I can't say I've seen a 2 phase supply, usually either 1 phase or 3 phase, no real reason to supply 2 phase.

...

It's fairly common in some area's.

A family member's house in Tauranga has 2 phase. When I was young, even now and then there would be a power outage that impacted one phase only.

My understanding was that if you house was two big for 60A single phase, you got 60A two phase. (I would guess that 100A single phase wasn't offered by that lines company at the time). We wanted to get three phase (or even just have the wire for it run up under the driveway), but some financial aspect made that unworkable.

The house is still fed by two phases, but the sparkies moved all the loads to one phase when a solar + powerwall (they are single phase) setup was installed.

allio

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#2988164 26-Oct-2022 09:15

In our new build we asked for it to be specced for induction (actually have a gas hob, but may convert in the future) with some headroom. They offered and installed 2 phase.