3 Phase 50 Hz Inverters required

System

Greetings all.

I live in sunny Jamaica, in the West Indies. Lots of sun and just right for solar almost all year round. On average I think about 5 1/2 full sun hours per day. I originally put my system together back in November 2005, starting with 8 Kyocera 157W panels on a Zomeworks tracker with a single Trace/Xantrex 4500w inverter. Over 5 years later, those 8 panels still produce outstanding output but have been joined by 40 more and I have been using 9Kw inverter capacity since the first year.

But to get to the point where I am now, I have had to work through some complications. Jamaica is one of the few countries in the world (I believe Lebanon is another) that uses 115V 50Hz residential power delivered normally as split phase 230V. At the time, I could find no commercial inverter which would provide that power so I ended up buying Trace/Xantrex 4548E (export) models. These are 230V 50 Hz, single phase two wire inverters. The catch was that of course my service is delivered as 230V split phase and the house is wired to handle two hot lines and a neutral from the grid as 115-0-115. My solution was to have a giant 12.5 KVA isolation transformer built locally which accepts 230V and outputs the same 230V, except with a center tap to create the same voltage condition the grid delivers. This worked for some years until I got fed up with the Xantrex inverters' inability to turn off the charger, thereby forcing me to use very expensive grid power to charge batteries at night no matter how the system was programmed. I even experimented with a kludge by placing 60A power diodes on the battery lines in a transfer switch which I would engage at night to prevent the batteries being always float charged from the grid. Of course that was self-defeating from the start, having to remember to switch to the diodes at night and back again in the morning was worse than the cost of the grid charging.

Eventually I got fed up with this and other problems of the SW inverters. For instance, the SW multiple units never communicated well and would often lose synch with each other. The expansion limit was 2 inverters. I will say however that the physical construction of those inverters cannot be bettered. They were rock solid and although they are now boat anchors (and they are just as heavy!), they never once required service, handling heavy house loads, air cond., lots of electronics, etc., and I never had the problems some have experienced caused by the stepped sine wave approximation. I retired them in working condition a year and a half ago and purchased 230V 50Hz XW4048's. Of course my current configuration demands that I remain with the 230V models even though Xantrex has now provided a split phase 50 Hz solution by way of firmware upgrade.

Which brings me to the current problem. I am now ready to configure a small commercial building I have acquired. The grid supply is 3 phase wye with a high leg. The voltages are A,C 110v line to neutral and B 190v line to neutral, and 220v phase to phase. I just about jumped for joy when I discovered that Xantrex had released new firmware which allowed selecting 50Hz on their XW models. All set now to start planning the system, I made a call to Xantrex and was curtly informed that when 3 phase is selected, the frequency cannot be changed! Frankly, this has been the story with Trace/Xantrex from ever since as far as I am concerned (I think I have earned the right to complain after buying 4 high end inverters), they never really provide a full range of options and their export models are always limited in some respect.

Anyway does anyone know of a grid tie battery based inverter at least say 3KW which can provide 110V 50Hz capable of operating in 3 phase. Or does anyone know if the Xantrex engineers are simply wrong (wouldn't be the first time ) and you really can select 3 phase 50 Hz with the upgraded firmware? The inverters must be stackable on each phase so I can grow the system as my building usage expands, probably to something in the region of 30KW. Not absolutely required but a unit which could handle a/c coupling and a generator would be better. Btw, Outback says they can provide a model which will allow this configuration for one inverter in each phase. This will not work because 9KW is simply way too small a limit.

I have to pose the question. Why should Xantrex/Schneider refuse to allow 50 Hz 3 phase if they allow 50Hz split phase? For that matter, why do most inverter manufacturers seem to treat non North American systems as country cousins? Is 50 Hz math or wiring, harder than 60 Hz?

Sorry to have bent everyone's ear with this long tale of woe, but I look forward to your responses.

Dapdan

Re: 3 Phase 50 Hz Inverters required

Yo Boo,

You would be incorrect. Barbados is also center tap on a transformer 115-0-115 and we operate at 50Hz. So you dont have to go as far a Lebenon to see a power grid operating under the same characteristics.

I am also looking for a 3phase supply for two potential clients. I am looking at th SMA island coupled with an SMA sunny boy as a stand alone setup or grid interactive or generator interactive. The SMA island is a pretty smart and impressive inverter. You can get it in the European or US model (50 or 60Hz). The largest model is the 5048 and can be stacked to give up to 300kw output(at least according to their website) I have just started my research into this product and I have not even given the clients a quotation on supply and install. The SMA solution seems to the the way to go. I think this machine will solve all of your current problems.

Cheers...
Damani

blackswan555

Re: 3 Phase 50 Hz Inverters required

What do you need 3 phase for ? well pump or other motor`s ? If so you may want to have a look at VFD`s http://en.wikipedia.org/wiki/Variable_Frequency_Drive,
Great bit of kit for running motors, runs of however many phases you have > 3 ph, soft start, variable speed & can save a lot of energy,

Have a good one
Tim

Quick suggestion, use Outback "E" spec inverters (230/50hz) you could stack them up to 30 kw 1 ph 230/50, use a step down transformer to get your 115/50, use a VFD to get your 3 ph 415/50hz

System2

Re: 3 Phase 50 Hz Inverters required

Damani,

Thanks for the heads-up. I actually looked at a website listing all the various power configs in the world and saw B'dos as 110-0-110 but at 60Hz. They got it wrong.

Question about the SI. Can you get the 50Hz model in 110v? I looked at their specs but it didn't seem to indicate this. 230V won't work because that would be 460v phase to phase. If it does come in 110v models then that's my solution. I think the SMA models only have one port for grid or generator, so I would have to add an external transfer switch for the generator but that is definately doable.

Incidentally I lived in Barbados for three years a long time ago. But I wouldn't at that time have even thought about the power configuration.

Paul.

Dapdan wrote: »

Yo Boo,

You would be incorrect. Barbados is also center tap on a transformer 115-0-115 and we operate at 50Hz. ...

I am also looking for a 3phase supply for two potential clients. I am looking at th SMA island coupled with an SMA sunny boy as a stand alone setup or grid interactive or generator interactive. The SMA island is a pretty smart and impressive inverter. You can get it in the European or US model (50 or 60Hz). The largest model is the 5048 and can be stacked to give up to 300kw output(at least according to their website) I have just started my research into this product and I have not even given the clients a quotation on supply and install. The SMA solution seems to the the way to go. I think this machine will solve all of your current problems.

Cheers...
Damani

System2

Re: 3 Phase 50 Hz Inverters required

Tim,

The grid supply is 3 phase, that is how it is for most commercial buildings here. 230v will not work because that would result in 460v phase to phase and a transformer as you say would be required. That would complicate the installation and create a huge expenses. Remember I already went through the transformer thing at my home. I don't want to do it again. And I don't want to rewire a functioning electricity installation.

Plus I can't even figure out how the grid tie would work with that setup. I know that E model Outbacks do not sell anyway with the exception of a newly developed version of their J (Jamaica) model. The problem with that is that it cannot stack past 9KW which is unacceptably small.

Paul.

blackswan555 wrote: »

What do you need 3 phase for ? well pump or other motor`s ? If so you may want to have a look at VFD`s http://en.wikipedia.org/wiki/Variable_Frequency_Drive,
Great bit of kit for running motors, runs of however many phases you have > 3 ph, soft start, variable speed & can save a lot of energy,

Have a good one
Tim

Quick suggestion, use Outback "E" spec inverters (230/50hz) you could stack them up to 30 kw 1 ph 230/50, use a step down transformer to get your 115/50, use a VFD to get your 3 ph 415/50hz