An inverter that cannot be certified stalls a CoC application because the Certificate of Compliance is issued against the certification the equipment holds, not against how neatly the installation was done — and that gap almost always opens after the money has changed hands. The cheapest place to catch it is before the deposit: ask for the inverter's certification document, in writing, and read the model code on that document against the model code on your quote.
Stand with me in the garage. It's a Tuesday afternoon, the rails are already on the roof, and the installer is crouched at the open distribution board with a torch in his mouth. There's a new inverter bolted to the wall above the battery stand — fan running, one green light, and an app on my phone that has already drawn a little blue line. The manual is still in its plastic bag on top of the box. It took a day and a half. The lights didn't blink when the street went dark that evening.
Six weeks later the same man is in the garage again, and he hasn't brought a drill. He's there for the CoC, and after that for the municipal SSEG application. He doesn't look at the wiring. He looks at the sticker on the side of the unit, then at me, and asks for the certificate.
Not the manual. The certificate.
The certificate he wanted, and the manual I had
A CoC is a legal declaration. It says the installation complies with SANS 10142-1, and it is signed and numbered by a registered person, with a test report behind it. When there's an inverter in the picture, that declaration leans on the paperwork that comes with the inverter: a type-test certificate or a declaration of conformity showing the unit was tested to IEC 62109-1 and IEC 62109-2, which are the safety standards for power converters.
If the unit is going to run in parallel with the grid — which is what 'grid-tied' means, and what most of what gets sold as 'hybrid' actually means — there's a second layer. The unit has to demonstrate grid-code compliance: NRS 097-2-1 in South Africa, which sits on top of the anti-islanding requirements in IEC 62116 and the interface characteristics in IEC 61727. Anti-islanding is the one that matters most on a dense suburban street. If the grid drops, the inverter has to stop pushing power into the wires, quickly, every time.
I spent that evening at the kitchen table with the manual. Forty-odd pages of wiring diagrams, error codes, a warranty card, a page about keeping the unit well ventilated. Somewhere in the middle was a line warning against connecting it to a public supply. There was no grid-code reference anywhere in the document. No table, no clause, no certificate number.
Why the person who signs won't sign
The instinct is to ask him to just issue the CoC and move on. He won't, and it has nothing to do with being difficult.
His registration number goes on that document. If the equipment isn't tied to a standard, he can't declare the installation compliant, and he isn't going to put his number on a form he can't stand behind. That registration is his livelihood, and if anything goes wrong later, the CoC is the first document anyone reads. What he did was read out the model code on the sticker, tell me to go back to whoever sold me the unit, and leave.
The supplier's answer was a voice note about a 'hybrid series' and a warranty. No certificate. I asked again, by email this time, because a voice note leaves nothing behind.
The second gate: the municipal application
The CoC is only the first gate. Even with a compliant unit, the system has to be registered with the municipality as small-scale embedded generation, and the application form wants the inverter's make, model and serial number, the certification the installer is relying on, a single-line diagram, and usually a commissioning sheet recording the protection settings as configured.
Some municipalities work off a published list of approved inverter models, and some list them with a specific certificate number attached. If the unit on your wall isn't on that list, you don't have a CoC problem and a registration problem. You have the same problem twice.
And here is the part that took me a while to see. The application describes a specific machine. My serial number was on it. Change the machine and the application describes something that no longer exists.
A new inverter is not a new inverter
This is the part people assume will be quick. Unbolt the old one, hang a better one, done.
The paperwork restarts. The alteration to the installation needs a new CoC for the affected section, which means a fresh inspection and a fresh test report, not the one you already hold. The SSEG application gets revised, because the make, model, serial and certification line all change, and in most processes a change to the equipment schedule means the review starts again rather than being amended in place. If the municipality had already issued an approval for the old unit, that approval is for the old unit.
The DC side rarely survives untouched either. A different inverter has a different input voltage window and different string requirements, so the array configuration, the DC cabling and the DC-rated isolators may all need re-looking, and the earthing and surge protection get re-checked with them. That is not a swap. That is a second installation sitting on top of the first, with the first one's costs already spent and its documents already dead.
While that runs, the household sits in limbo. The system is either idle or running in a state nobody has signed off, and the person who paid for it is the one waiting.
The units that were never grid-tied in the first place
There's a version of this where the inverter isn't non-compliant. There is simply nothing to certify.
Some units sold to homeowners have an AC input labelled for grid or generator use. In practice it passes the supply through to the load and uses it to charge the battery. That is a transfer function. It is not parallel operation. The inverter never synchronises with the grid and has no anti-islanding function to test, because the grid-parallel function doesn't exist in the hardware. The 'hybrid' in the brochure means 'it takes two sources of input', which is true and completely beside the point when the form asks for grid-code compliance.
That is what catches people. The unit works beautifully. It keeps the lights on. It has been keeping the lights on for months. It just can't be declared compliant for a job it was never built to do.
What should have been on the quote
Reading back, everything I needed was a line item.
The quote should have named the inverter by full model code, not by size and category. '5 kVA hybrid' is a description, not a specification. It should have referenced the certification the unit holds against a standard I could look up, and it should have said who lodges the SSEG application and on what basis.
I also want the serial number on the final invoice and in the handover pack, because that is the number that ends up on the application. A quote that names the model code and the certification gives you an argument if the equipment on the wall doesn't match. A quote that says 'hybrid inverter' gives you nothing.
The request that costs nothing, before the deposit
All of this collapses into one action, and it happens before any money moves.
Ask for the certificate. Not a brochure page, not a link, not a sentence in a quote — the document, for that model code. Then read the model code on the certificate against the model code on the quote, letter for letter. Manufacturers run certificate coverage by variant, and a series certificate doesn't automatically cover every unit wearing the family name.
Put the request in writing, even if you've already asked face to face. If the document arrives, you have it on file for the CoC and the application. If it never arrives, you have a dated record of asking, and that changes the conversation about who carries the risk, because by default the person who paid the deposit carries it.
Not every cheap inverter is a dud, and not every expensive one holds the right certificate for your municipality. Price and certification are related, but they are not the same axis. Some budget units come with the paperwork intact, and some premium ones come with the wrong paperwork for the list you're dealing with.
But the sequence is what bites. The equipment goes on the wall, the money moves, and only then does someone with a registration number ask for a document. By that point you're not choosing an inverter any more. You're redoing an application.
