A solar system is not finished when the last panel is fixed. Before it is switched on and handed over, it is tested and set up, and the results are recorded. Green Solar Solutions carries out string testing, checks of open-circuit voltage and short-circuit current, electrical certification and a safe handover.
Why a system is tested before it is used
A solar installation produces DC voltage whenever it is light, and it cannot be switched off at the panels. Testing shows that the wiring is correct, that every connection is sound and that the system is safe to energise. Mistakes found at this stage are much easier and safer to correct than after the system has been running.
String testing, Voc and Isc
Each string of panels is tested before it is connected to the inverter. The open-circuit voltage (Voc) shows that the right number of panels are connected correctly and that the string voltage matches the design. The short-circuit current (Isc) shows that the panels are delivering current as expected. A reading that is off points to a wiring or panel problem to resolve first.
Electrical safety tests
The DC and AC sides are tested for polarity, continuity of protective conductors, insulation resistance and the operation of protective devices. Grid-connected PV systems have their own British and European testing standard, BS EN 62446-1, and the installation is carried out to BS 7671, the IET Wiring Regulations.
Commissioning
Once the tests are passed, the system is switched on and the inverter is set up: the grid settings, the battery settings if there is a battery, and the connection to the monitoring app. Isolators are labelled and the shutdown procedure is confirmed.
Handover and documentation
At handover you are shown how to read the monitoring, what normal output looks like and how to isolate the system, and you receive the documentation for it. If an export tariff or a scheme asks for specific paperwork, such as MCS documentation, raise it when you ask for a quote so that it can be discussed in advance.