The fastest way to void a listed inverter's certification is to change something about it after commissioning and leave the paperwork describing the old state. Approval under NRS 097-2-1 attaches to a specific unit running a specific firmware, commissioned with specific settings, in a specific arrangement, and that machine stops being the machine that was tested the moment the firmware updates itself overnight, an installer clears a nuisance fault with a factory reset, someone slides the export limit in an app, or the battery underneath it is replaced with something else entirely. The listing is not a property of the box on the wall. It is a property of the configuration, and configurations drift without a single screw being turned.
I have stood in a lot of suburban garages where everything looks in order. Green light on the inverter, panels ticking on the roof, a neat energy curve on a phone, and a plastic folder on the workbench holding the Certificate of Compliance and the municipal SSEG letter. Then I ask the one question that empties the room: which firmware was this unit running on the day it was commissioned? Most of the time nobody knows. Sometimes the answer is "the latest one", which is exactly the answer that makes me nervous. That silence is where compliance actually lives.
A listing is a snapshot, not a badge
When a model is type tested and lands on the approved list that municipalities and Eskom work from, what has been approved is a behaviour. The test house put a particular generation of that product through a particular set of conditions and recorded how it behaved. The certificate does not travel with the serial number, and it does not follow the unit through every service visit afterwards.
I have watched people treat the approved-model list as a shield. "It's on the list, so nobody can argue." Nobody is arguing with the list. What gets checked at the end is whether the installation in front of the inspector still matches the installation described in the paperwork, and whether the behaviour that was approved is the behaviour that is switched on. Those are different questions, and only the second one is about your house.
What the interconnection tests actually attach to
The grid-tied tests are about one interface: the grid port. Anti-islanding, trip thresholds and reconnection timing, harmonic behaviour, power factor. All of it describes how the inverter behaves as a generator running in parallel with the network. That is the thing NRS 097-2-1 cares about, because that is the thing that can put a live voltage on a cable a technician believes is dead.
The grid port and the backup port are not the same function
On a hybrid unit, the backup output does something else entirely. It supplies a separate set of loads when the grid is down, out of parallel with the network. The interconnection tests do not describe it, and the approval does not cover it as though it were the same port wearing a different hat.
Two things follow from that. The paperwork should say plainly which port feeds what and how the changeover is arranged, because a verifier arriving in five years needs to be able to see it, not infer it. And when the split of loads between the grid side and the backup side changes after commissioning, what has changed is not only wiring. The arrangement that was approved has been altered, and if something the grid-port behaviour depends on ends up on the wrong side of the fence, the settings on the screen can still say all the right things while the installation does something else.
Settings are part of the tested configuration
Export limiting is the clearest example. A municipal consent is written around a declared behaviour: no export at all, or export up to a limit, or export with a meter and a tariff behind it. The setting is not a preference. It is the thing the consent was granted against. The grid code or country code selection is the same story, because it decides which trip windows and which reconnection behaviour the machine will apply.
Operating mode belongs in the same category. Self-consumption, backup-priority, time-of-use: each one changes what the machine does at the boundary, and therefore what the municipal meter sees on a sunny afternoon when nobody is home. It is the easiest thing in the world to change in an app, and the least likely thing to be written down afterwards.
Then there is the export limit that exists only on paper. The limit is enforced by a measurement, and if that measurement is not installed or is reading the wrong way round, the setting is a number in a menu and nothing more. I have seen that mismatch look completely innocent from the outside. The inverter is proud. The meter is doing something different.
Firmware is the quietest change of all
Nothing about a firmware update resembles a modification. There is no drill, no new cable, no invoice, and usually no conversation. It arrives over the internet on a schedule nobody set, or through a portal pushing a grid-code compliance update, or from an app prompt with a button labelled "improve performance". A warranty board swap can arrive from the factory with a newer version than the one in your record. A technician clearing a fault can do a factory reset, get the machine working again, and walk away without re-entering anything.
Any of these can change behaviour that was part of the approval: when the unit disconnects and reconnects, how it regulates power factor at the boundary, how the export limit is enforced, how the battery is charged and discharged, and therefore what appears at the municipal meter. None of it is visible from the driveway.
That is why, in my own record keeping, a firmware version is not a technical footnote. It is a line item next to the serial number, and it is dated. If automatic updating is switched on, that is a decision I want the owner to make knowingly rather than discover later, because it means the certified configuration can change without anybody touching the installation.
The battery was never part of that approval
This is the confusion I run into most often, and it usually arrives in one sentence: "the inverter is on the approved list, so the whole system is compliant".
The approval is about the inverter as a grid-tied machine. The battery is a separate matter. So are the DC protection, the isolation, the cable sizing and routing, the location and ventilation of the battery, and the communication link between the battery management system and the inverter. Those sit under the electrical installation rules, SANS 10142-1, together with the battery's own product safety standard. Different question, different answer, and quite possibly a different person signing for it.
The communication link is a good illustration of how separate it is. If the protocol conversation between battery and inverter never happens properly, the inverter falls back on its own assumptions about the battery, and the charging behaviour you end up with is not the behaviour that was commissioned. Nothing on the network side has moved. The configuration has.
Where the record belongs
A Certificate of Compliance on its own tells a verifier that the installation complied on the day it was issued. It does not, by itself, tell them what was switched on that day.
What I want sitting with that CoC, in the same folder, is short and boring and worth more than any glossy proposal: the make, model and serial number; the firmware version installed at commissioning; a settings record, whether that is a printout, a screenshot or a photograph of the commissioning pages; the grid code selected; the export limit and how it is enforced; a plain statement of which port feeds which loads; the SSEG approval reference; and the date and name of whoever commissioned it.
Take the photographs on the day. Rating label, firmware screen, settings pages. Apps get replaced, portals get shut down, cloud accounts get orphaned when a household changes hands, and installers close businesses. Paper in a folder outlives all of it.
When the inverter is replaced or reconfigured
An insurance replacement, a warranty swap, an upgrade after a battery purchase. These are the moments when the configuration quietly becomes undocumented. What matters is not only that a listed model went back on the wall. It is that the certified configuration was restored, and that the restoration was written down.
A unit arriving from the factory with newer firmware may sit outside the approval the municipality accepted, and that is far easier to sort out before the swap than after. Two units operating in parallel are a configuration in their own right, not a simple doubling of a single one. Adding panels changes the ratio between the array and the inverter, and the tested arrangement assumed something about that ratio. Changing the battery to a different capacity or chemistry is a new DC installation even though neither cable on the AC side moved.
What I ask before I trust a handover
Municipal processes differ, and I am not going to pretend otherwise. Some municipalities allow no export at all and insist on a particular meter. Some want a commissioning report from a registered person alongside the CoC. Some move faster than others on an SSEG application, and some have changed their requirements more than once. The detail depends on where you are.
What does not depend on where you are is the matching. So the questions are always the same, and they are worth asking while there is still somebody on site to answer them. Which firmware version is installed, and where is it written down? Who updates it, and is automatic updating switched on? If the unit is factory reset tomorrow, what does it come back as, and who restores the settings? Which settings were commissioned, and does what is written down match what was declared in the SSEG application? If this inverter is swapped under warranty, who documents which certified configuration was restored?
A supplier who can answer those without blinking is selling you a configuration. A supplier who cannot is selling you a box, a certificate with a model number on it, and the hope that nobody ever asks.
That is the whole argument, and it is not a gloomy one. A listed inverter is raw material. What makes an installation compliant is the arrangement: the machine, the settings it was commissioned with, the firmware it is actually running, the ports doing the jobs the paperwork says they do, and a record that lets a stranger check all of it years later. Any one of those can move on its own. Keeping them aligned is not a bureaucratic afterthought. It is the compliance.
