New CoCT SSEG application form

I notice that CoCT has uploaded a new application form for SSEG installations. It has been simplified into one form for both grid-tied and off-grid installations. It is available here:

Under the option “3. STANDBY SSEG - Passive standby UPS utilised as an off-grid hybrid SSEG” a new requirement has been added: The inverter must conform to SANS 62040-3. For fully detached installations there’s no such requirement.

I wonder where that leaves non grid-tied inverters like the popular Axpert series. I checked out the VoltronicPower website and several of their UPS products have EN 62040 certification (= SANS 62040), but none of the products listed under the “off-grid inverter” category make mention of it.

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It’s quite interesting. SANS 62040-3 (IEC 62040-3) only describes a method of specifying UPS performance. Such as if the output is dependent on the input (grid) voltage and or frequency or not. (Passive standby UPS’ will have outputs that are dependent on the input while grid connected and so will fall in the VFD category), then there is a definition of the output voltage quality, while grid-connected and on backup supply. The last is a definition of output tolerance under certain conditions, such as changing modes or step load changes. These have ratings from 1 (best) to 3 (worst), a good double conversion UPS would be 111, while a good passive-standby UPS will probably be 311 (3 indicating the disturbance during the changeover period from grid to backup power).

Also the CoCT form only says it must “conform” i.e. not the same as “be certified to”


So… even if they slapped a “333” on the front of the case, that would mean they ticked the box? :slight_smile:

Actually, what I found initially was not the full standard. It seems that 62040-3 mentions that to be compliant with 62040-3, you also need to be compliant to 62040-1 and 62040-2.
62040-1 is the UPS safety requirements and 62040-2 is the EMC compatibility.
So it is probably a bit more involved than just saying VFD YY 333 and being done with it.


I think @TheTerribleTriplet asked them (Voltronic) for paperwork some years ago, and they said the only paperwork they have is a CE mark. You know, the one that people often jokingly say is the “China Export” mark. The CE mark uss a self-certification method. It does indicate at least some EMC compliance. I suspect the Axpert very likely has no IEC 62040 certification.

Of course you can still use it in a trolley. Once the power leaves the wall… nobody cares. Video spooled up to roughly the right location.

Indeed. As we know, Voltronic is known for not replying on emails.

So I asked them for a quote for 10 000 Axpert units … instant reply as I suspected they would.

Then I asked them what certification was applicable, the CE one, told them what was needed, using the Victron specs, to which they replied only the CE mark and that Axperts are sold as off-grid units.


I am a little bit confused by the new document.

What would option 4 be then, and what stops you from just ticking that box instead of option 3?

I think that’s when you have an external suitably interlocked (etc etc) manually operated changeover switch. In other words, no automatic change-over switch. I assume a large part of IEC62040 focuses on said changeover switch, falling in the domain of “UPS safety requirements”.

So option 4 is somewhere between 3 and 5. Option 5 is completely separate and doesn’t even have the changeover.

I’m guessing though. But I remember CoCT telling people they need this approved interlocked changeover many times.

I really like this new form!

It clarifies the Pr. Eng responsibility as well (previous ones made them responsible for SANS compliance as well)! I think there will be confusion on option 3 and 4. I am not even sure where the Axpert fits in here!

So just buy a Hybrid and get it done with!

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If the changeover switch to switch the essential loads between the output of the inverter and the house, how does the charging of the batteries happen? Should the same switch disconnect charging when the inverter output is connected to the load?

The term “hybrid” can mean many different things depending on who you ask. I assume you mean a grid-tied inverter on this list:

The problem with grid-tied inverters is the price: You can expect to pay at least twice what you would pay for a cheap Axpert. I personally have a Victron system, but I’m about to install a cheap UPS system for someone else and the budget cannot stretch that far.


Nothing wrong with an Axpert as a 100% UPS. Damn good value for money if you ask me.

But if you connect panels to that damn good value for money UPS … bugger me, we are going around and around in circles. :laughing:

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Thanks TTT, that is also my opinion and well stated!

@PierreJ the problem is that the term “Hybrid” got muddled in time. Hybrid now refers to an inverter that can use 2 or more energy sources. But the more important part in the definition is one that can MIX said energy sources.

This excludes the Axpert and why it is marketed as an off-grid inverter.

@karischoonbee , you asked about the change over switch. It is effectively to disconnect the Axpert output from the back-up circuits and have it directly connected. So it would not always need to be set up as such that it disconnects the Axpert from the grid.

Some passive UPS would have the “change over” switch internally, this needs to be compliant with SANS code for change over switches. The Axpert does have an internal change over (from grid supply to inverter supply), but it does not have SANS or IEC certification. It uses the same relay switching that Grid Tied of Hybrid inverters would use and this causes some concern.

The city is trying to accommodate axpert users, I have been told by the city in no uncertain terms that they consider the axpert as an appliance and not as a SSEG. This might have changed a bit recently, seeing that they now integrated this under the SSEG forms as opposed to the original off-grid form.

You’re beginning to catch on… :slight_smile:

Another pet peeve of mine. The English word hybrid means an entity that combines characteristics of two or more other entities. In this case, the traditional understanding was always an inverter that can tie with the grid (like a PV-inverter) as well as serve as a backup supply.

The first time I started to see the “other” definition, was when suddenly Axpert’s were marketed as Hybrids. The reasoning was that they include a solar charger, so they combine characteristics of an inverter with a solar charger. Pffft. It was a marketing trick to get the lesser inverter on the same page as the proper hybrid.

Yeah, that appears to be the golden threat running through the whole thing. The regulations are deathly afraid those PV modules might end up pushing into the grid through whatever conversion interface is used (which is the more common mode elsewhere in the world), so the regulations appears to be written from that viewpoint. A hybrid inverter with no PV attached (that can nevertheless island and feed into the grid)… no problem. Attach PV to it… problem. A passive UPS with a solar charger. Use it as a UPS, no problem. Attach PV modules… problem.

As long as your PV modules (or the conversion interface between them and the grid) is disconnected while you are attached to the grid, you are compliant.

Remember, the PV module(s) are the G in EG. Not the inverter. The inverter is just the conversion interface.

I think UPSes really should be held to a higher standard, even without PV attached. That is what I think is wrong with this picture.

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Many of the Axpert inverters can mix battery and solar, and if you google “hybrid inverter” you’ll thus find a fair number of Axperts listed. In my opinion “hybrid” can mean too many different things to be a useful term to describe an inverter.

The term “off grid” is also prone to causing confusion: It can mean that the installation is not connected to the grid at all, or it can mean that it is connected to the grid, but it doesn’t synchronise with it (and thus cannot feed back).

CoCT seems to use the latter definition of “off grid” in their SSEG application documents, and looking at the Voltronic (Axpert) website, it seems they do too. I would have preferred if they used the terms “grid-tied” and “non grid-tied”. As far as I know “grid-tied” still only means one thing.

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If you look at the Victron material, you will note they stick rather rigidly to a specific set of terms, to avoid confusion.

  • PV-inverter: This is an inverter without battery storage that pushes the power directly into the grid.
  • AC-coupled PV: The energy from the PV modules is pushed directly into the AC side through a PV-inverter.
  • DC-coupled PV: The energy from the PV modules is pushed into the batteries/DC-bus through a solar charger.
  • Multi/Quattro: A Multifunction inverter/charger.

No room for confusion here :slight_smile:

I think that may be what is starting to happen here. We’ve decided that we’re going to forego the option of adding solar panels, but I am still worried that I am going to run into problems getting a CoC for the electrical installation given that the Axpert does not officially comply with any of the regulations for a UPS.

Hope I am not de-railing the thread, looking for clarity on the CoCT regulation regarding maximum output power of the inverter, eg 3.5 kva on a 60 amp grid supply

That is correct yes.

Yet, the rebadged ones sold by “Giant Power” in Australia are considered ok. If you google around a bit, there is a SoroSolar unit (SSP3118C, also rebadged) that lists IEC 62040 compliance in its PDF.

The inverter may well comply, but someone needs to spend the moolah to have it tested and to get the paperwork.

Edit: There is also this old post at the Ausie forum, indicating that MPPSolar did at one point have it certified for AS 62040, which is sort of the same thing.

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