Turn an inverter on only after four conditions are true. The unit is installed inside its listing. A qualified person can see the disconnects the design calls for. The utility has accepted the interconnection if the system operates with the grid. Any battery in the design is communicating the way both manuals describe. A display that lights up while one of those is still open is an unfinished installation.
| What the job includes | What finished looks like |
|---|---|
| The listing | Inverter, mounting, conductors, and any battery used the way that listing and that manual describe |
| Disconnects | AC and DC means of isolation a qualified person can reach and recognize, as the inspector applies the rule |
| Interconnection | The permission and the grid profile the utility asked for, where the inverter runs with a grid |
| Battery communication | The cable, protocol, and settings both manuals name, when a battery is part of the design |
The disconnect has to be a real means of isolation
Installers talk about a disconnect within sight of the inverter. Treat that phrase as a practice the adopted rule and the local inspector apply to the device that isolates the machine. This page will not give a distance, a mounting height, or a conductor order. Those figures belong to the manual and to the inspector who signs the job. What an AC disconnect does, and why the DC disconnect is a different switch, is covered in AC and DC disconnects for solar.
An owner can learn which handle opens which source. Choosing the device, landing the conductors, and proving the source is actually open are a qualified person's work. Modules in daylight remain a source when the inverter is switched off. A battery remains a source when the utility is dark. Opening the wrong handle and trusting the screen is how people get hurt around equipment that looked idle. Leave the cover on until the person who is allowed to open it is there.
Interconnection is the utility's settings file
Where the inverter runs in parallel with a utility, that utility sets the paperwork and the grid profile. In the United States, IEEE 1547-2018 is a widely used interconnection standard, and it calls for the equipment to cease to energize within 2 seconds of an unintentional island. That sentence is United States interconnection context. A utility in another country points at its own rule. Even inside the United States, the profile issued for this service is the profile that gets loaded. A menu entry with a country name on it is a starting library, and the utility's letter decides which entry stays.
Anti-islanding is the behavior that stops the inverter from feeding a line a crew believes is dead. The longer account sits in what anti-islanding is. Voltage limits, frequency limits, and insulation checks sit with the other protection functions of a solar inverter. An export cap only limits power that would leave the building. Backup needs a transfer that separates the house from the grid, which is a different design, described in home battery backup for outages.
Battery communication, labels, and who does live work
A hybrid inverter and a battery that were never listed to speak to each other can charge, refuse to charge, or shut down with a code that names neither product. Both manuals have to allow the pair, including the cable, the protocol, and any firmware note they print. A plug that seats proves the housings mate. The address and the handshake are the match. If the two manufacturers disagree on the page, the installation sits outside both listings until a written allowance exists.
Live work means the cover is off, a conductor is exposed, or a connector on a producing string is opened. A qualified person does that work, with the array treated as energized in daylight and the battery treated as energized until the manual's own isolation method has been used. The checks before anyone is on the roof are in what to settle before a rooftop solar installation. Where the enclosure should sit, so that same person can see the disconnects and so the heatsink can shed heat, is in where to mount a solar inverter.
Commissioning is the hour when settings meet the site. Grid profile, export limit, battery mode, clock, and the direction of any current sensor are settings. A wrong one can look like a failed board. Walk the commissioning list in the inverter manual and stop at any line you cannot point to on the screen. The next person needs labels that say which handle opens the DC, which opens the AC, and which circuits, if any, sit on a backup side. Grounding, bonding, and surge protection belong in the job when the manual and the local rule call for them. How those three differ is in grounding, bonding, and surge protection. A graph of yesterday's energy shows that the inverter recorded energy. Permission to operate, where the utility requires it, is a document.
