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Split phase and two phase solar installation question

PostPosted: Wed Apr 11, 2018 9:51 pm
by jmo
Hi guys,

I'm new to the forums, i hope to learn and contribute myself.

someone said I may have split phase at my house and to check whether I do. how would I know whether i have two phase or split phase? there are two distribution fuses in my board, does that mean i have 2 phase or not ?

I got a pre approval from the distributor but it just shows that I can install 3.5kw for 1 phase and 3.5kw if i have a second phase.

It specifies nothing about split phase. Do I assume a split phase means I can install 7kw over two phases or can I only install 3.5kw cause it is a single phase split?

Also if i do have two phase can I use a three phase inverter or do I have to use two single phase inverter ?

Thanks for the input guys.

Re: Split phase and two phase solar installation question

PostPosted: Thu Apr 12, 2018 8:40 pm
by jaahn
Hi jmo :)
Interesting question. Perhaps an experienced electrician in this area will answer you. But to help understand your supply here are a couple of questions !
Do you live in a remote area.
Are you supplied by a single wire to a pole transformer which has two wires or three wires to your house ?
Is it a SWER system in the area.
Jaahn
Hmm, What country are you in ?

Re: Split phase and two phase solar installation question

PostPosted: Fri Apr 13, 2018 12:18 am
by jmo
hi jaahn,

thanks for the response. it is a rural area, i haven't checked the pole with the amount of phases coming in. if it is only one i assume it is single phase split which I would assume means only one phase can be used for solar kw max.

It is a SWER system.

yeah i should get an electrician out to answer the questions, just thought some people may have some answers here.

Appreciate the reply.

Re: Split phase and two phase solar installation question

PostPosted: Fri Apr 13, 2018 11:31 am
by jaahn
Hi JMO :D
Hmmm that remote SWER system is not in my experience for sure. It seems a bit problematical normally so only people with direct experience would know much about it. ;) Feeding power back into the system might do ??? :twisted:
See what replies you get here ?
Jaahn

Re: Split phase and two phase solar installation question

PostPosted: Fri Apr 13, 2018 12:39 pm
by Gordon-Loomberah
If it is SWER, then I think you'll most likely be limited to 3.5kW, and even then voltage rise may be an issue.

Re: Split phase and two phase solar installation question

PostPosted: Fri Apr 13, 2018 12:50 pm
by jmo
Thanks for the replies guys.

I already know it’s SWER. The question is whether it is single phase split or two phase

Re: Split phase and two phase solar installation question

PostPosted: Fri Apr 13, 2018 1:06 pm
by Gordon-Loomberah
The SW in SWER stands for Single Wire, which means it is single phase... 2 phases wont go down one wire ;)

Re: Split phase and two phase solar installation question

PostPosted: Fri Apr 13, 2018 1:43 pm
by jmo
Thanks for your response Gordon.

Are you a qualified electrician?

You can have two phases that are SWER. They just both return through earth so they don't have to bring a neutral in.

And if that is the case, Im just curious as to why I would have two fuses in the switchboard?

Thanks

Re: Split phase and two phase solar installation question

PostPosted: Fri Apr 13, 2018 2:10 pm
by Gordon-Loomberah
You could have 2phases on 2 SWER wires, but you only mentioned one, so I think it must be one phase.

If you have a ~460V SWER service, then that can be split into 2 X 230V phases, 180degrees apart. If that is the case, then I don''t think it will work with a normal 3phase inverter, which operates on phases that are 120degrees apart.

No I'm not an electrician, but worked with my father quite often, and he was.

Re: Split phase and two phase solar installation question

PostPosted: Fri Apr 13, 2018 7:15 pm
by jaahn
jmo wrote:Thanks for the replies guys.

I already know it’s SWER. The question is whether it is single phase split or two phase

Hi :D
I did a bit of googling and found this which I edited a bit;
Single Wire Earth Return Distribution System
Because of Australia’s unique position of having a vast terrain to serve with very low population densities, the cost of universal 3 phase distribution has been prohibitive. Hence much of rural Australia is supported by a Single Wire Earth Return (SWER) system to deliver 240V single phase power, or by the ‘Two-phase 480V’ variation, where the primary of the transformer has only one wire and on the secondary side there are 3 wires: +240,0,-240 Volt two-phase wires; and one neutral wire. This system uses one supply wire with the return path through the ground.
There are over 190,000 km of SWER lines in Australia. SWER lines, do suffer from limitations due to over/ under voltage and power outages. This system is single phase, so it cannot be used for three phase loads

So from your description it sounds like you have the second type with ‘Two-phase 480V’ as you have two fuses. You would have to ask your supplier in writing to get it correctly defined before you start. IMHO
Jaahn