Buying guide
Single phase vs three phase ACDB: which one does your installation need
This decision gets made for you by the grid connection at the site, not by how big the solar system is. Here is how to check it correctly before you order.
We occasionally get an order changed midway because someone assumed system size decides the phase. It does not. The phase of the ACDB box you need is decided by the electrical connection already at the site, and getting this wrong means the box simply will not match the installation.
What decides it
Most residential connections in India are single phase. Most larger commercial and industrial connections are three phase, since three phase supply handles higher loads more efficiently. So the real question is not how many kilowatts the solar system produces, it is what kind of connection the building already has from the utility.
A 10kW residential system on a single phase connection still needs a single phase ACDB. A 6kW commercial system on a three phase connection needs a three phase ACDB, even though it is smaller in capacity than the residential example. Capacity and phase are two separate questions, and mixing them up is the most common sizing mistake we see.
How to check before you order
The reliable way to confirm this is to look at the existing electricity meter or connection at the site, not to guess from the inverter's rated capacity. A three phase meter has three separate phase wires coming in, alongside the neutral. A single phase meter has just one phase wire and a neutral. If you are working from an inverter spec sheet instead of visiting the site, the inverter's own output rating will usually state single phase or three phase directly, and the ACDB needs to match that.
Why the mismatch matters
A single phase ACDB physically cannot terminate a three phase inverter output correctly, and forcing it is not a shortcut worth taking. The breaker sizing, the terminal count and the surge protection device are all built differently for the two configurations. This is not a case where a slightly wrong part still works, it simply does not fit the job.
What to send us
When you order, tell us the phase of the grid connection along with the inverter's output rating. If you are not fully sure which phase the site has, a photo of the existing meter or main switchboard is usually enough for us to confirm it before we build the box, which is far easier to fix before manufacturing than after delivery.
We manufacture both single phase and three phase ACDB boxes, sized to your inverter's exact output rating. Send the details through the contact page or over WhatsApp and we will confirm the right configuration before you order.