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Is your system legal? Capetonians have till 28 Feb 2019 to register their systems


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Thanks for all the advice. I still do not understand how my Axperts are going to feed mains electricity into the grid. As I understand it, the load connects to either the grid or the inverter output. A relay cannot connect to both at the same time. Now when connected to the grid, the chargers can also draw power to charge the batteries. It is exactly the same principal as the 1 Kva modified sine wave inverter connected to a plug in my study to power my computers. This inverter switches to mains when it is present but the inverter circuits become active and the output relay switches to it when the grid fails. This is simply an appliance and the Axperts works on the same principle. If this thing is now also classified as a generator and the input is connected to the grid, it would imply that I have to register this as well. The comments regarding a CoC are of course valid and I have taken note. My system was installed by @Mike  who employs a qualified electrician so a CoC should not be a problem, considering the large number of installations that Mike has under the belt. @plonkster and others, perhaps you would enlighten me when you have a moment. 

Since Swartland Municipality states that stand alone generators need not be registered and the Axperts are effectively that, I do not believe it is necessary to register my installation. City of Cape Town may well have different requirements.

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2 minutes ago, ebrsa said:

A relay cannot connect to both at the same time

I asked the Ausies about how this thing works. I am more familiar with the blue inverters and I will discuss that for a moment and then flop over to the other side.

The blue inverters can feed back into the grid, in fact they are designed to do it, but it can be disabled (tech talk: turn off PowerAssist and/or uninstall the ESS assistant). Even if disabled (which technically turns it into an Axpert), it still needs sign-off the moment I connect PV panels to it.

The Multi has a fully bi-directional pipeline. It can pull in power, push out power, and if it didn't have what we call LOM detection (loss of mains) it would actually energise its input (albeit at very low current) while it is charging. If there was a sneaky undetected loss of mains power while it was charging at low current, the input side might remain energised.

Now for the flop. The pipeline in the Axpert while charging is very similar. It is also bidirectional (for the most part), and when charging it runs the pipeline in reverse. The difference is there is no active rectification (ie the mosfets in the final stage are not switched) during charging, and this prevents this unit from powering the grid IF (and this is the crucial part), if everything operates as designed. But that is not what the regulators are worried about. They want a safeguard that ensures it will remain safe even when operating in a fault condition.

This is how I understand it at least. What is required is sufficient paperwork (ie, most likely a certificate from a testing house) to say that it complies. Which is likely not going to happen because Voltronic considers this an "off-grid" inverter (which it technically is). The other option is to convince someone locally to sign it off.

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2 hours ago, ebrsa said:

As I understand it, the load connects to either the grid or the inverter output. A relay cannot connect to both at the same time.

In AC charging mode, the load is connected to both the mains and also to the inverter output. But, all going well, the inverter is reconfigured as an AC charger, pushing power from the mains towards the battery. My understanding is that there is a theoretical possibility of the software failing to configure the inverter hardware correctly, causing it to push power from the battery and/or solar panels into the grid. I suppose it's also conceivable that some sort of hardware fault, even with correct firmware, could cause the inverter which is configured for charging, to instead somehow invert and push power into the grid.

If the grid goes down, an Axpert will not attempt to perform AC charging, so it should be fine. But again, there is the theoretical possibility that a firmware or hardware fault could somehow prevent the inverter from realising that the grid is down. It's a microscopic chance, so in my opinion this is all overblown. They should take the manufacturer's word that the Axpert is simply not designed to push power into the mains, and that it is designed such that it won't even connect to the grid if the grid is down. But that's just my opinion.

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5 minutes ago, Coulomb said:

My understanding is that there is a theoretical possibility of the software failing to configure the inverter hardware correctly, causing it to push power from the battery and/or solar panels into the grid. I suppose it's also conceivable that some sort of hardware fault, even with correct firmware, could cause the inverter which is configured for charging, to instead somehow invert and push power into the grid.

Correct, it is theoretical. It doesn't even have to generate actual AC output, all that is needed is that the high voltage DC bus is energised and some of it leaks out through the input, which I believe could happen if just one of those FETs on the bridge are damaged. Theoretically of course.

7 minutes ago, Coulomb said:

They should take the manufacturer's word that the Axpert is simply not designed to push power into the mains, and that it is designed such that it won't even connect to the grid if the grid is down. But that's just my opinion.

I actually share your opinion. And I'm sure there might be some suitably qualified engineers who share it as well and who'd be willing to put ink to paper for it. Someone has to take the plunge though and try... :-)

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I am a bit confused by everything that is published.

I came to the understanding that the normal municipality prepaid meter will block a reverse feed by tripping.

So much about the techical preventions is actually not necessary.

Can someone please start a new feed on the requirements and progress for the new requirements. I cannot recall any feedback on a successful registration done to date.

This can turn out to be quite useful for the forum people staying in the current affected towns.

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2 hours ago, Johandup said:

I came to the understanding that the normal municipality prepaid meter will block a reverse feed by tripping.

It depends on a lot of factors.

1. Some old disc-type meters will spin backwards.

2. Some disc-type meters have reverse lockup, they might spin back a little bit have have a ratchet mechanism that prevents them from going backwards. Power that you inject into the grid doesn't trip anything.

3. Some electronic meters (the majority as far as I can see) can't detect the direction of power flow and will simply bill you for it as if you're consuming the same amount of power.

4. Some can detect the flow and will trip. The levels of sensitivity varies. I know of only two brands so far that do this: Conlog and Landis.

5. Of those that disconnect, some reconnect after a few seconds (Conlog), and others go into tamper mode. At least I am told some Landis meters do this. Once in tamper mode, they require a token from the supplier to reconnect.

With all of that said, there is definitely some confusion about feeding in and islanding. They are related but they are not the same.

A grid-interactive inverter always chases the zero point, but for those with some rural farming background: Have you ever looked at the tyre tracks of a donkey cart, how it zig-zags and sort of runs in the middle of the road but also doesn't? Same for grid-interactive inverters that attempt not to feed in. Whenever the load changes, it will push into- or draw from the grid for a short time, usually in the order of seconds. Most prepaid meters work on an averaging window, so it is possible to feed back little bits without tripping the meter.

Furthermore, it is also possible to energise a line without actually feeding back. Imagine a break in the cable going to a house (so it is open circuit), with a malfunctioning inverter on the other end that fails to island. By definition nothing can be fed back, because it is open circuit, but anyone touching the cable will be electrocuted.

Anti-islanding, therefore, is not so much about avoiding feed-in. It is about detecting an outage and disconnecting completely (whether feed-in is allowed or not).

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As per Voltronic, I quote their response to me, verbatim:

After my confirmation to my upper manager, We understand that there will have the regulations in your country (South Africa) when the products need to feed-back to grid.
We have sell a lot of Off-Grid Solar Inverter (Axpert) to your country, and the certification will be CE certificate.
 
So get it signed off as off-grid and you are good to go. To do that, from my research pre-Multigrid, you need a CoC from a electrician for the DB board connection / alterations / altered circuits, you then submit the free paperwork, they send someone to come for a visit, and then, if all is approved, you are good to go.
 
Think of it this way: If you sold your house / or are buying the house, with panels and a inverter installed to add value to the house, save electricity, power failures are a thing of the past ... there are paperwork involved for the sale / purchase.
Make sure all the I's are dotted and T's are crossed so that the sale / purchase can happen.
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Thank you for your advice @plonkster , @Coulomb and @The Terrible Triplett . I am still not sure where I stand regarding the Swartland Municipality requirements. Dumping my Axperts (Proline brand) is not an attractive option and a costly affair.

I attach the Swartland application form which contains all requirements etc. Would appreciate it if some forum members could take a look and post their views. Also does anyone have an opinion on my 1Kva modified sine wave inverter which is an additional backup for my computers. This seems to be exactly the same as the Axperts except of much lower quality. If the Acperts need to be registered then it would seem this appliance has to be too. That would be insane as there must be tens if not hundreds of thousands of these things with an input connected to the grid. It would seem that the issues pertaining to the Axperts would also apply to this piece of Chinese cheapy electronics.

Application for connection of embedded generation.pdf

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15 minutes ago, ebrsa said:

If the Acperts need to be registered then it would seem this appliance has to be too. That would be insane as there must be tens if not hundreds of thousands of these things with an input connected to the grid.

Haha - that is where this whole story fails for me. An office UPS is exactly the same as your Axpert inverter, the only difference is that the Axpert has 2x DC sources (PV and battery) whereas the office ups has battery only. So either they should require every UPS to be registered, or explain in what they they differ that requires the PV system to be registered, or just admit that they are going after PV systems which is ruining their business model.

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42 minutes ago, ebrsa said:

Application for connection of embedded generation.pdf

Essentially no different from the Cape Town one.

20 minutes ago, pilotfish said:

Axpert has 2x DC sources (PV and battery) whereas the office ups has battery only

The moment you add PV, it comes under the purview of NRS097-2-1, which requires certain things from it. Without the PV panels it is only subject to SANS 10142-1. What is ultra confusing to me is that NRS097-2-1 says that if you use a solar UPS as an embedded generator, then the boxes that needs ticking is the same as for the mentioned SANS requirements. That suggests to me that either the Axpert is okay as an embedded generator, or it is not even okay as a UPS (but because it is difficult to regulate nobody cares).

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24 minutes ago, pilotfish said:

An office UPS is exactly the same as your Axpert inverter

That is technically not true. A cheap Office UPS doesn't have the fancy bi-directional pipeline that the Axpert's got. And it is usually square wave too :-)

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@plonkster from your comments if would seem that if I use the Axperts as a standard backup inverter without the solar panels connected and then use a separate MPPT controller to charge the batteries from solar panels, it may just circumvent the onerous regulations. What really gets my gall is that the government yet again proves their indisputable hopeless incompetence by encouraging all to use renewable energy at the time of Eskom blackouts. Of course the blackouts were euphemistically called load shedding. Then the government, who seems to want to control everything, fails dismally to prevent equipment that does not meet their specifications from entering and being sold in the country. As usual the trusting consumer, who in any event has no hope in hell of being informed of the myriad regulations and specifications, is left to bear the brunt of their failure while importers smile all the way to the bank. Small wonder nobody takes any much notice of laws, including those intended to prevent murder.

All that being said, I guess the solution is simply to claim that my Axperts are standalone generators which do not require registration as far as I can make out from Swartland's application form.

Regarding the cheap inverter, I guess one should call it a stepped square wave one as it is very far from sine wave, is it not also a generator with a separate supply, other than mains, in the form of batteries and is there not also a likelihood that the relay that switches the load between inverter and grid may also malfunction, although it escapes me how this may be possible.

Edited by ebrsa
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5 minutes ago, ebrsa said:

then use a separate MPPT controller to charge the batteries from solar panels, it may just circumvent the onerous regulations.

Nope. The moment you connect PV panels in any shape or form, they want you to prove that it won't be a danger to the grid.

6 minutes ago, ebrsa said:

simply to claim that my Axperts are standalone generators which do not require registration

Yup, @The Terrible Triplett keeps saying someone will have to take the plunge and try it.

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27 minutes ago, plonkster said:

That is technically not true. A cheap Office UPS doesn't have the fancy bi-directional pipeline that the Axpert's got. And it is usually square wave too :-)

Your knowledge of electronics way surpasses my own, so I am not in a position to argue - however I would like to understand the difference. A common UPS connects to the grid, monitors input and has an electronic changeover that will switch the output to inverter mode in the event that the input goes outside of certain set parameters, that sounds like an Axpert to me, with the only difference being the DC source (I am not talking about the type of output sqaure/sine - I dont think the line worker will care about wave shape if he gets zapped).

 

3 minutes ago, plonkster said:

Nope. The moment you connect PV panels in any shape or form, they want you to prove that it won't be a danger to the grid.

And therein lies my objection - why should the DC source make any difference to the grid?

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20 minutes ago, pilotfish said:

 

And therein lies my objection - why should the DC source make any difference to the grid?

 

Seems to me there is a simple explanation called STUPIDITY. One wonders if whoever compiled all these regulations has more functioning brain cells than a demented gnat. Anyway that still does not bring one closer to a solution. What have you done regarding registration of your Axperts, which I seem to recall you have installed, @pilotfish if you are prepared to comment on a public forum. I will fully understand if you would prefer to remain silent on the subject.

Edited by ebrsa
Correcting error
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5 minutes ago, pilotfish said:

A common UPS connects to the grid, monitors input and has an electronic changeover that will switch the output to inverter mode in the event that the input goes outside of certain set parameters

I suppose there might be a whole range of these things, some might use old-school iron transformers and some might use more modern SMPS designs. The Axpert has a more modern SMPS type setup.

The major difference is that the older low-frequency design does things the other way round. Where the modern designs does a DC/DC conversion first and creates AC second, the older designs creates AC first and then steps it up using a transformer. In other words:

New design: Take low voltage DC, turn it into 350VDC, then turn it into 230VAC.

Old design: Take low voltage DC, turn it into low voltage AC, then step it up to 230VAC.

The older designs generally have some hard "reconfiguration" that it does when it flips the transformer around, so it is impossible for it to accidentally feed into the grid while charging, and also impossible to feed into the grid while inverting (because it disconnects the grid). There is however the danger that a fault (stuck relay contact) could energise the grid while it is inverting. The switch-over is supposed to be "suitably interlocking" so that this can never happen, but I am sure there are plenty of cheap UPSes around that don't comply... they just don't bother anyone enough to do something about it (because they are small and run out of battery power really quickly).

Where the Axpert differs a bit from this, is that in all operations it maintains a high-voltage DC bus, either pushing AC power out of it, or rectifying AC power into it (and then running the pipeline in the required direction for the necessary energy flow). When it inverts there is no problem, because the grid is disconnected. It is when it charges that the grid becomes directly connected (via a buck/boost pipeline and what amounts to some switches) to the PV panels.

Truth be told, I'm still not sure whether it should be like this. But it seems to be like this.

@ebrsa, as I understand it the only way to avoid these issues are to remove either the grid, or the PV panels, or to have a hard interlock that ensures the two are never connected simultaneously. In other words you cannot charge from the grid while also charging with PV. This can be done with the Axpert, but it means doing something like TTT has done by making his own transfer switch.

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I have had a look at the City of Cape Town leaflet which explains the difference between stand-alone and connected systems. They sure clearly explain that stand-alone really does mean there is no connection of any kind between the inverter system and the grid. That is a concern should our municipality come snooping around as well as insurance issues. At present the whole house is powered by the 2 Axperts with a 8Kw trip to limit excessive loads. It would seem to me that if I have the DB board rewired so that plugs with large loads connected and the geyser are wired directly to the grid and the rest of the house to an inverter of say 4Kw or 5Kw, it may sort out the problem. I hope it may be possible to sell the 2 Axperts for true stand-alone applications.

I would be most grateful for any suggestions as to what 4Kw to 5Kw approved inverter, that does not break the bank, may be suitable. From information available on local websites of vendors, I am currently considering the Infinity 4Kw, the more expensive Infiniti 5Kw and the Goodwe EM 5Kw. The Infiniti models would be preferable as I am used to the ICC-Pi control software. Any advice or suggestions of alternative options regarding spreading the load and a suitable inverter would be much appreciated.

Edited by ebrsa
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On 2018/09/07 at 5:36 PM, pilotfish said:

A common UPS connects to the grid, monitors input and has an electronic changeover that will switch the output to inverter mode in the event that the input goes outside of certain set parameters, that sounds like an Axpert to me, with the only difference being the DC source (I am not talking about the type of output sqaure/sine - I dont think the line worker will care about wave shape if he gets zapped).

The big ones, ones connected to a DB board, always are sine wave with a very large battery bank, it needs a CoC.

With generators connected to the DB board, done by a professional company that knows the regulations, also needs a CoC, it must be completely separate from the grid. Therein the need for UPS'es with big gennies, to keep the loads going whilst the gennie starts and settles before taking over, charging all the UPS'es whilst powering the load. 

The other "big" UPS types tend to be modified sine wave, 2-4 100ah batteries, if connected direct to PC's and such, not the DB, they should still meet UPS standards.

My online 2400va and 700va APC online UPS have relays, have papers international regulations, click something silly when the power goes on / off. They have a few 9amp batteries for a few minutes backup, more designed to run the few minutes whilst a gennie starts up.

Then you have UPS'es that flooded the market, big and small ones. If all are actually legal, meet international standards for UPS'es, that is a whole new can of worms. Best one checks if it is a concern.

 

On 2018/09/07 at 5:57 PM, ebrsa said:

STUPIDITY. One wonders if whoever compiled all these regulations has more functioning brain cells than a demented gnat.

From what I hear and was told since 2008, regulations was penned down suitable qualified engineers advising the Council of what is required and why.

 

17 hours ago, ebrsa said:

That is a concern should our municipality come snooping around as well as insurance issues.

Ditto! The two parts that is the core of it all form what I have seen and heard.

So if you register as off-grid, with the CoC in hand, you will get a visit from a official to check it.
And IF you have not registered:
- it could affect ones insurance,
- you can get a fine and be forced to remove the system till it is compliant. Has happened in Milnerton and Table View already, according to a solar installer.

IF you have no CoC for the DB connection, another can of worms IF something goes wrong of there is a claim.

Not one electrician I have contacted so far, will connect a solar system to my DB board without all the T's crossed and I's dotted. 

 

17 hours ago, ebrsa said:

I would be most grateful for any suggestions as to what 4Kw to 5Kw approved inverter, that does not break the bank, may be suitable.

Therein my going from off-grid with my INTERLOCK , which was completely acceptable for being off-grid, to me looking at Solis grid tied inverters as the cost to get a off-grid CoC can be more than a grid-tied application, after I found "The Engineer" who has prices that are very acceptable. CoC for off-grid came down from a estimated R5k to 1k, with engineering sign-off, all in, less than R5k.

Re. the 4-5kw inverter, you need to check your DB breaker, 60/80 or 100amp. It limits the size inverter for a grid tied inverter size. Off-grid you can go as big as you want. 

General consensus, no electrician I spoke to, would sign off a CoC for a Axpert, nor would engineer, unless it is off-grid, then you don't need the engineer. Only caveat, you are going to have a break in power when Eskom goes off / comes on. My break since 2012 was 1 second. You get faster, but the relays are still faster relays, but we are talking 40ms.

The Solis grid tie idea was cool (and VERY affordable) for grid tied, limited to the DB board breaker size, Axpert types are then used as a true UPS i.e. no panels connected to it at all, Solis being the grid tied inverter, dealing with the regulations.

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On 2018/09/07 at 5:32 PM, plonkster said:

Yup, @The Terrible Triplett keeps saying someone will have to take the plunge and try it.

Ditto! Here is the list for SA installers: https://www.pvgreencard.co.za/reg/installers/inst-directory.php

PM me for Smitty's details, don't think we should put his contact details here:

Mistergreen Enterprise
Smitty - Msc Elektonies / Pr.En.Msc

He works in bands, charging per watt (ex VAT):
Fixed fee of R 2 500 for 1st 2.5kw (R1 per watt)
Over 2.5kw - R.50c per watt up to 10kw
10kw and up, R0.20c per watt.

So a 10kw system will cost R 6 250, if you have a CoC in hand.

BUT, note 1, the DB breaker limits the size of the grid tied inverter.

Note 2: No Engineer signoff required for off-grid systems.

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@The Terrible Triplett thanks a lot for all your information. I have a fair amount of knowledge and many decades ago had a small company that manufactured micro-processor controlled UPSes. @plonkster referred to your system and suggested doing something similar.

On 2018/09/07 at 6:20 PM, plonkster said:

This can be done with the Axpert, but it means doing something like TTT has done by making his own transfer switch.

I would much appreciate it if you could tell me where on the forum I will find an explanation of your solution. Clearly I will have to find some kind of way to overcome the Axperts not being compliant for connection to the grid in any manner. From scratching around on the Internet during the weekend, it is clear that not insignificant money is involved. I have also to take the factor of my age into account but who knows, I may just need the best there is if I am lucky. So the more ideas I get the better the chances that I will arrive at the best and most cost effective solution possible.

My intolerant comments regarding those who compiled the regulations is really just based on knowledge of much of the legislation, on all levels of government, that we have to endure. Many moons ago there was legislation that forbid cordless telephones and the government required us to buy R3000 cordless phones made locally. When the press blared out the story, the price came down overnight to R2000. At that time I bought a cordless phone in Singapore for R139 and customs had a tariff code for such phones. So I paid the tariff but actually had an illegal instrument in my possession the moment I stepped through the door. Government compilers of legislation are always overly cautious, just in case it comes back and bites them. So however well qualified they are, it does not follow that the legislation will be sensible.

I look forward to hear about the details of your system when you have a moment. 

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17 minutes ago, The Terrible Triplett said:

not the DB

This is an important point not to gloss over. For a UPS that is connected as an appliance, it should pretty much be a safe appliance, and that is that. It's when it is connected into the DB that things change, not only for solar, but even for "ordinary" UPSes. Sans 10142-1comes into play, and the question remains whether the Axpert complies in terms of a suitably interlocking changeover. If it does... then end of story, it also complies with NRS097.

 

17 minutes ago, The Terrible Triplett said:

From what I hear and was told since 2008, regulations was penned down suitable qualified engineers advising the Council of what is required and why.

There is a bit of a phenomenon that happens when regulations are sourced from committees of interested professionals, and that is that sometimes several (or all) of them wants to add something to it, put their personal little stamp on it. Then towards the end of the meeting everyone is tired and nobody is in the mood for arguing about stupid stuff someone else suggested. So you end up with a bunch of good ideas and a bunch of less-good ideas that nobody was interested in arguing anymore. Design by committee.

I'm not saying this is how it happened. I'm just saying that just because some clever people were involved in drafting it doesn't mean it's not stupid in some ways :-)

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