Energy Matters Forums

[Joey]

Sojin_Muneshi ,

I'm sorry in this case you are very wrong regarding the way this system is setup , as Gully suggested you should check your facts before making such blatant claims as to the legalities.
Firstly Yes it is illegal to override anti-islanding protection of a GCI when connected to the grid , It needs to be enabled to comply with AS4777.

If you took the time to understand how the Sunny Backup works and is wired to the grid you would not have needed to waste all your time posting such non factual information.

Ok I have a Grid connected system using a Sunny boy 4000TL and Yes Anti Islanding is switched off , why ? because the 4000TL is not connected to the Grid , it is connected to the SBU5000 which is connected to the grid ,a little bit of research would reveal that the SBU5000 is no ordinary backup inverter , it is an Australian approved grid connect inverter than complies with AS4777 meaning it has Anti-Islanding protection.
The Grid does no see the SunnyBoy's configuration nor does it have too , although not important to this discussion it is totally controlled by the Sunny Backup via Frequency Shift Power Control.

Like I have already mentioned this is no hacked together system like many of have proposed , it is a total backup solution that is grid connected , can still use an ( SMA only ) GCI that will operate when the grid is down and is fully compliant with AS4777 guidelines.

[Sojin_Muneshi]

joey,

I would be very keen to see the website you believe describes and illustrates the design you have just explained? rather than just the component parts, ie the installation schematic?

However the point of my first post in this thread was really only to point out that such a scheme requires to be anti-islanding if connecting to the grid? your first post and subsequent posts by others did not seem to clearly address that?, whereas your answer above to me now seems to support and confirm my position?

I have re-read my first post, and the subsequent one, I dont think I claim any individual piece of equipment is legal or ill-legal? in my first post I state it is 'illegal" to have "a" grid connected inverter that is not 'anti-islanding" - you seem to confirm that in your reply above - I'm glad we agree?

You stated that the SMA system is integrated and the debate and replies then entered into UPS and other devices including manual change over switches and dedicated AC wiring.

I then received a reply advising me I didnt understand the thread related to supplying electricity when the grid is unavailable - (it is titled No more blackouts) and clearly relates to grid connected premises.

That post invited me to look at the Latronics range of devices, which I dont think I claimed as being legal or illegal either?

None of it seems to matter if we are all in furious agreement that an inverter connected to the mains and able to be switched to the grid needs to be anti-islanding?

There is a risk those without a backup unit and reading this forum, may have assumed that the debate in this thread was suggesting isolating the main switch and removing the inverter from the grid at times of blackout doesnt consitute running it in islanding mode? and of course the inverter would need to be no longer anti-islanding to do so would it not?

I note an earlier answer to my first post seems to makes same the assumption? that by simply considering once its disconnected from the grid its not 'islanding'?

I am happy to learn where I am mistaken? and also very interested to better understand the system you are promoting?

regards

Sojin

[Sojin_Muneshi]

Joey,

Ok I have a Grid connected system using a Sunny boy 4000TL and Yes Anti Islanding is switched off , why ? because the 4000TL is not connected to the Grid , it is connected to the SBU5000 which is connected to the grid ,a little bit of research would reveal that the SBU5000 is no ordinary backup inverter , it is an Australian approved grid connect inverter than complies with AS4777 meaning it has Anti-Islanding protection.
The Grid does no see the SunnyBoy's configuration nor does it have too , although not important to this discussion it is totally controlled by the Sunny Backup via Frequency Shift Power Control.

I will review my copy of AS4777 at work tomorrow and discuss it with my collegues, however the issue of anti-islanding, autotransfer and alternate power supplies is governed by more regulations and standards than that specific PV inverter standard.

http://www.energymatters.com.au/images/SMA/sbu5000.pdf

I have read your explanation above, and reviewed the detailed brochure on the SMA SBU5000, it seems to me to be a remote area battery charging/inverter system with autotransfer of the mains supply on a no volts detection of the grid voltage with a 20ms change over, and then operation of the sunnyboy inverter into "islanding" configuration to continue to supply AC loads connected to the house AC mains reticulation?

You confirm your Sunny boys AC output is connected to the SBU5000 with I understand is a DC battery inverter/charger and AC transfer switch, you confirm your Sunnyboy is operating with its anti-islanding switched off? and is generating its output "through" the SBU5000 and you are relying on the anti-islanding of the SBU5000 to shut down the connection for the SB4000 to the grid, yet as I understand it your system doesnt anti-island at all but uses the SBU5000 AC transfer switch to isolate the home from the Grid, and for the SB4000 to continue to generate into the home loads?

Technically the SB4000's AC output is clearly electrically connected to the grid in parallel with the SBU5000's AC output via the SBU5000's AC Transfer switch, and it is clearly in an islanding configuration? is there something I have missed in that simple analysis?

It doesnt seem to me that the SBU5000 has anti-islanding fitted either as it can continue to supply the home from the stored power in the batteries and inverted back into AC?

The SBU5000's main role in the management of the SB4000 has been to operate as an AC Transfer Switch?

(It seems clear the sunnyboy has "islanded", & so has the entire house - its not connected to the grid yet it is powered?)

This system also allows re-synchronisation to the grid and transfer back after the grid supply is restored, it seems a well designed and capable system.

Largely the system I described in my first post, in basic concept? but still raised concerns over.

I can't comment on the technical quality of the component equipment and to its individual compliance to its own standards but I have no reason to doubt the designers have made it compliant, as I have said my concerns relates to its use in installations and then the legality of those installations to connect and operate if not individually approved?

As such I think you "may" find such installations require specific "per premise" assessment and authorisation of the transfer and protection equipment for it to be installed in most distribution areas as an Alternate Power Supply, without that specific site authorisation I am of the "opinion" this would be considered illegal.

I suspect such a system may well get approval, but I havent seen its actual performance.

This is nothing to do with the quality of the design of the specific equipment - a point I have tried to make from the outset.

As such, "I do not believe" this can be simply be installed as a normal PV, nor "do I believe" simply retrofitted after the initial installation without further approval, the points I have also tried to raise?

Obviously if you are taking the DC from the PV network and using that to supply a DC emergency powersupply and DC reticulation to DC lighting and DC appliances in a true remote area powersupply format it is not governed by local state based Service and Installation rules, but if the AC circuits are normally connected to the grid supply such an arrangement does come under those rules as does the equipment to do so, even during the periods it is not directly connected to the grid - I would be happy to hear the "Inspectors" opinion on this as I suspect this is his bread and butter for his own local state rules in NSW?

Again if you consider my understanding above is incorrect please explain how that is so? I am keen to know how it differs from my view of its operation and status under those regulations?

Of course I may not know anything about such things, and am happy to be corrected?

regards

Sojin

[Joey]

Summary Test Report for Compliance to Australian Standards AS4777
(Grid connection of energy systems via inverters)
Report of Tests Performed For:
SMA Solar Technology AG
TEST ITEM DESCRIPTION
Type: Sunny-Backup, SBU5000”, in grid
feed mode connected to the Grid through
“Automatic Switch Box Unit (Set M)”
Nominal Operating Voltage: 230 V
Nominal Operating Frequency: 50 Hz
Nominal Output Power Rating: 5000 W
Abstract
This summary test report provides the compliance results for the “Sunny-Backup,
SBU5000” + “Automatic Switch Box (Set M)” tested at ResLab during 26th May to 28th
July 2008 for SMA Solar Technology AG for compliance to AS4777. The full test results
are reported in the ResLab REP-RL0804-T-0001 rev 0.doc
ResLab Test Report Number: REP-RL0804-T-0002 Rev A.Doc

Compliance to AS4777:
The EUT complies with the requirements of AS4777.2 and AS4777.3 as per section 3.1
and 3.2 of this report in the following modes:
a. ““Sunny Backup SBU5000 (5000W) in battery grid feed mode “On” through “Automatic
switch box (Set M)” when no energy is fed from the PV-inverter into the grid.”
b. ““Sunny Backup SBU5000 (5000) with battery grid feed mode “OFF” and energy feeding
from the PV-inverter through the ““Automatic switch box (Set M)” into the grid”

As batteries are not used for grid feed, "battery grid feed mode" is always off ( disabled )

You will see from the schematic that the PV is not connected to the grid in parallel with the backup's output , The "PV coupling contactor" is only closed during grid failure , if this was closed during normal operating it will as you say be connected in parallel with the backup output.
The Sunnyboy is only connected to the grid via the the "Automatic Disconnection Device" which is the exact same disconnection device the Sunnyboy has and uses when operating in anti-islanding mode.

The Sunny Backup does have full anti-islanding with all the same parameters as a Sunnyboy , it will disconnect from the grid for all the same reasons a Sunnyboy does , voltage / frequency to high or to low as in accordance with AS4777.
Dropping off from the Grid after 20ms on detecting 0v from the grid is not correct , yes it will disconnect from the grid if it reads 0v just like any GCI does but the 20ms time is the time it take to switch the home to backup mode , not the time it takes to disconnect from the grid under a fault condition.

Section 17 page 135 of the installation manual explains setting up the Sunnyboy for island mode , you will also be happy to notice the warnings ! Never operate your Sunny Boy directly on the grid with these settings!
As soon as you set the Sunny Boy to use stand-alone grid parameters, the device
no longer meets the requirements of the applicable local standard for the
connection of generators to the low-voltage grid (AS4777). In backup systems, this function is assumed by the Automatic Switch Box in combination with the Sunny Backup 5000.

[Joey]

Sojin , I may have seemed a bit harsh or defensive in my initial response so I apologize for this.

You have raised some very important points , also extracting vital information that people should note before even thinking about making their own backup system or trying to do something similar on the cheap.
This is not something that should be experimented with and there are no shortcuts if you want a grid connected backup system , it is imperative that whatever is connected to the grid complies with AS4777 which of course means anti-islanding is not an option it is 100% compulsory!
Note I never once suggested this system as a opportunity for people to come up without their own backyard solutions , although people used this thread as such and turned my information into an invitation for debate.

A couple more answers to some of your questions,

None of it seems to matter if we are all in furious agreement that an inverter connected to the mains and able to be switched to the grid needs to be anti-islanding?

100%

I have read your explanation above, and reviewed the detailed brochure on the SMA SBU5000, it seems to me to be a remote area battery charging/inverter system with autotransfer of the mains supply on a no volts detection of the grid voltage with a 20ms change over, and then operation of the sunnyboy inverter into "islanding" configuration to continue to supply AC loads connected to the house AC mains reticulation?

The Sunny Backup is not a remote area battery charging inverter system , What you are referring to is another SMA product called the Sunny Island , The Sunny Back is a Full Grid interactive back system that cost almost twice as much as the same size remote area system.

It doesnt seem to me that the SBU5000 has anti-islanding fitted either as it can continue to supply the home from the stored power in the batteries and inverted back into AC?

A lot of the assumption you made in your last post should be cleared up now but this one in particular is of interest .
The reason being although the SBU5000 Does have anti-islanding , once the grid is disconnected the PV coupling contactor allows the Sunnyboy to assists the output of the SBU5000 ,not by charging the batteries and converting it to AC , it directly uses the AC from the sunnyboy and the AC from the SBU in parallel ( if needed ) which derives it output from the batteries. , of course this would not be possible if the SunnyBoy had anti islanding enabled.

Just for interest sake because there is very little mention about the Switch Box M which is an integral part of the Sunny Backup , ( it will not operate without it ) here is a picture of this complex bit of control equipment .

[Sojin_Muneshi]

Joey,

Thankyou for that schematic and explanation, it filled in the missing information and confirms the SBU5000 is operating the site as anti-islanding in compliance with AS4777 and the certificate proves it.

The SBU5000 certainly is a complex arrangement and it is its automatic transfer functionality that is doing all the important work as I raised earlier, and that same functionality "might be" available from the Latronics "autotransfer" device highlighted by someone else but I cant determine that from the website brochures.

As Sonyboy points out in their brochure that you quote, such installations must still comply.

Clearly such installations require careful design and compliance with the standard and the regulations, and therefore shouldnt be "constructed" adhoc.

I still think it "may be" a requirement of installers of this arrangement to bring its "auto transfer" and "islanding" operation to the attention of the local Network operator and get a specific approval of its installation, which I suspect would not be declined for an intergrated and certified unit such as the SBU5000.

In Victoria such requirements are regulated under the Victorian Service and Installation Rules, and in particular section 6.8.2 and 6.8.3 which I think such a system might fall under, in addition to the existing requirement to comply with section 6.8.4. There are similar Network requirements in other states.

http://www.victoriansir.org.au/pdf/section6.pdf

Such transfer and protection systems have always been expensive, and the $12k price tag of the SBU5000 reflects the functionality it contains, doing such tasks on the cheap or adhoc might seem to deliver the same outcome from the users point of view, but certainly wont neccessarily be viewed as complying with the regulations, ie hence it would be considered illegal.

Thankyou for your further information and clarification

regards

Sojin

[gully]

This is not something that should be experimented with and there are no shortcuts if you want a grid connected backup system , it is imperative that whatever is connected to the grid complies with AS4777 which of course means anti-islanding is not an option it is 100% compulsory!

My theory was that a SunnyBoy can be run (legally, with anti-islanding enabled) by using a UPS as the synch source and charging the UPS, while the UPS powered AC circuitry once it was disconnected from the meter/mains, never to disabling anti-islanding.

The reason being although the SBU5000 Does have anti-islanding , once the grid is disconnected the PV coupling contactor allows the Sunnyboy to assists the output of the SBU5000 ,not by charging the batteries and converting it to AC , it directly uses the AC from the sunnyboy and the AC from the SBU in parallel ( if needed ) which derives it output from the batteries. , of course this would not be possible if the SunnyBoy had anti islanding enabled.

Wow - so to recap basically the two inverters balance the load to the house automatically with PV and battery power? That is very impressive (and efficient), although how does the SBU work to maintain the battery float-level 24/7? It must be charging them periodically?

I'm interested in the 'Automatic Switch Box' you refer to (not the latronics one) - can you offer some more info?

Joey - sorry if i've thrown this off-topic, you're right they aren't a direct comparison but look at how much we've learned about your SBU! I'm wondering why they don't make a SBU a standalone device (ie. SBU+SB in one box) - it would cut down on the amount of circuitry needed and make it slighly more efficient.

[Sojin_Muneshi]

My theory was that a SunnyBoy can be run (legally, with anti-islanding enabled) by using a UPS as the synch source and charging the UPS, while the UPS powered AC circuitry once it was disconnected from the meter/mains, never to disabling anti-islanding.

Supplying the synch source from anything but the grid effectively undermines the design's anti-islanding, and then the design's compliance with AS4777, the requirements of the wiring regulations AS3000, and the local Service and Installation Rules - My "opinion" is, that is clearly illegal.

It is clearly operating as an "alternate source of supply" and exposed to all of those additional regulations and compliance.

The unit is no longer switching off with loss of the grid supply, that is what is meant by "anti-islanding" not the "simple tick on a box" on a brochure, by-passing its sensing "adhoc" is not in compliance with the design, or manufacturers recommendations or wider regulations, and this is type of issue I have been pointing out in all of my posts in this thread.

Of course I am happy to be shown how its not?


regards

Sojin

[gully]

Supplying the synch source from anything but the grid effectively undermines the design's anti-islanding, and then the design's compliance with AS4777, the requirements of the wiring regulations AS3000, and the local Service and Installation Rules - My "opinion" is, that is clearly illegal.

Well joey has already pointed out that this is not true, as is the case with his SB+SBU, going as far to disable anti-islanding. Joey states that since the SBU is the primary device connected to the grid, and it itself has anti-islanding functionality that this is maintained. All the standards are there to do is enforce safety and ensure no feedback to the grid during blackouts - nothing more! I'll concede that UPS doesn't have it's own anti-islanding device on it however you can set up the circuitry so it only powers the UPS circuit not the mains circuit (to the meter).

The unit is no longer switching off with loss of the grid supply, that is what is meant by "anti-islanding" not the "simple tick on a box" on a brochure.

Yes yes we are all by now aware of what anti-islanding means...

Of course I am happy to be shown how its not?

I don't see any proof in what you've discussed, it's only your opinion. In any case I never envisaged setting a UPS up like this, more as a battery backup system on a sub-circuit which is without a doubt completely legal. Still if you can do it, adding the PV power source during power failures would be an added benefit.

[Sojin_Muneshi]

Gully,

I have already provided my proof and facts two posts ago, I assume you are not a registered Electrical Contractor? as if you were, you should already know all of this?

In Victoria such requirements are regulated under the Victorian Service and Installation Rules, and in particular section 6.8.2 and 6.8.3 which I think such a system might fall under, in addition to the existing requirement to comply with section 6.8.4. There are similar Network requirements in other states.

http://www.victoriansir.org.au/pdf/section6.pdf

Putting it politely as I can you dont seem to know what you are talking about?, you are providing theories and opinions with no facts and ignoring the facts of others, and claiming any contradictions to you as simply "opinions"

Please explain how your GPS proposal qualifies under sections 6.8.2 and 6.8.3 of the VSIRs above which govern installations connnected at your premise in SPI-Ausnet?

I am happy to give you the name of the VSIR Connections Manager at SPI-Ausnet if you want to check with him yourself?, and report back his answer to you, of course you might consider the answer is only "his opinion?" and choose to ignore it as well?

Please do me the courtesy of reading the links (facts) I present to support my comments and opinions before you flippantly disregard or ignore them totally?

regards

Sojin