When testing an ev charger there are no specified tests in GN3 beyond those for standard circuits but the catch all is manufacturers instructions and functional testing.
So the use of a test adaptor to simulate the various charge states is required in my view as you can check the operation of the software, activate the contactor amongst other things. it covers the functional testing requirement.
It can also be good to verify the CT clamp is working - especially if extended over a long distance as they are calibrated to a set parameter and distance can affect this (especially the Andersen A2 if going over 30 metres!) For example the Andersen installer menus (Andersen will provide the codes to access if approved) will show you the CT readings and verify it. for other chargers I will sometimes temporarily set the grid limit very low and then put all the loads on to see if charger stops. with most installs this isn't required but only those with long cable runs to the main incomer.
I also use a Wi-Fi analyser tool and record the Wi-Fi signal strength so I can show the charger is within reach, you would be amazed how many customers call to ask why the charger isn't connected to the Wi-Fi in bad weather!!
some charger manufacturers have specific requirements - IE EO ask you to check wifi before fixing the charger to the wall,
RCD testing is a good thing done through the adaptor - especially to test the 6mA DC protection inside as testing at the terminals inside wont test this,
If fault finding a charger that wont charge (especially on old units with old cables/outlets then you can do continuity testing on the CP link on each end of the tethered cable or CP pin to wire inside. its only 0.5mm CSA so very thin but have come across lots of leads that have been twisted, damaged run over etc, The CP link is vital in the handshake process to get the charger and car synced and charging correctly.
Of late there has been quite a few cases of Teslas not charging when the plug is inserted, Tesla changed the tolerances ever so slightly that the plug doesnt align, we are talking mm at most here, you literally have to force the plug into the car. charger works fine just a connection issue
