I have a Megger 1741 and I could pay Megger to upgrade it to being a Megger 1741+ presumably with the latest version of the software to give a reasonably accurate test RDC-DD ramp test result, but I still would not know how long it took, only the tripping current at the end of the test period, not the tripping current that actually activated the RDC-DD and started the tripping process.

If I have that right, I’m not sure exactly what I would prove, other than it does trip eventually, not the actual tripping current and not the tripping time.

Megger may state test the RDC-DD, but they are trying to sell you the new all singing, all dancing black tester with red buttons and a colour screen for £1600, if the EVSE manufacturer is telling you to test the RDC-DD then it seems appropriate to do so, even though the Code of Practice is telling you don’t need to, but doing so because you are being told to do so by a tester manufacturer trying to sell you a new expensive tester may not be the best of ideas.

Not that I have anything against Megger, I have five of their testers and one of their EVSE testing adapters, I used my MFT1741 with the Megger testing adapter when I took the C&G exam, but I will never tell anyone they have to buy a new tester when they don’t need to.

Sparkingchip said:

even though the Code of Practice is telling you don’t need to,

Just to be pedantic, the CoP says that BS 7671 doesn't require the test but the manufacturer may specify it. It's a subtle but slight difference, and really aligns with what you are saying yourself - if the manufacturer says do it, definitely consider doing it.

Thank you

Thank you