As hundreds of thousands of inverters are installed, going into the billions spent in SA, we still can’t seem to find a common basic guideline for installations where everyone interprets the regs the same and the installations are done according to a standard, yes many will say the regs don’t need to be updated, it’s all there in the book, many will argue.
Like we have done with smaller installations, is create a basic setup, for example.
5 kw inverter, with a 5-kwh battery and 6 solar panels is pretty much your standard entry level system being installed. Creating a basic guideline would help improve the standard of installation.
I see there is a new one popped up, fuses for solar panels and where they should be located.
Some will say you need a DC isolator, a set of fuses and SPD in what some refer to as a DC combiner box others call it a DC control box, a DC protection box, there are many names for it.
The latest chatter is where to install the DC fuses for the solar panels, some will say, close to the inverter, others are saying in the roof as close to the panels as possible.
What I have learnt from designing and building many control systems for water and wastewater treatment plants, simple is better. The less buttons and options the safer and better the plant functions.
The same thing with the solar system, simple is better, you want a simple accessible layout which makes access to the components as easy as possible for everyone.
Isolating these systems should be a quick easily accessible action.
For example, there should be isolators built into the inverter:
A 4 pole for the input output of the AC power, you switch it off the power is off going in and coming out, with lights to indicate when the power is off, no confusion.
A multiple pole DC isolator for the solar panels, which isolates all DC power going into the inverter and prevents DC power from leaving the inverter while in the off position (Sunsynk already has one of these fitted to their small inverters)
A DC isolator for the battery.
Each battery should be fitted with fuse protection and an isolator, plug in terminals which are insulated and easy to remove from the battery,
Where the solar panel wires enter the building and connect to the inverter of DC combiner/control/fuse box, there should always be MC 4 connectors, so that no matter what happens with the box or inverter, there are no exposed live wires. Just like the panels have Mc 4 connectors, so the extended wire should also be fitted with connectors to prevent them being left live in the building. IF you look at commercially made DC boxes, you will notice most of them have MC 4 connectors under the box, which are then connected to the fuse-SPD/DC isolator- inverter.
Reply With Quote
Did you like this article? Share it with your favourite social network.