I'm currently doing the 2394 then once I pass (fingers crossed) I hope to do the 2395.
Basically the 2394 and 2395 are the old 2391 course split into two, this is down to the low pass rate of the 2391.
The 2394 covers the intial verification of an installation, basically inspecting and testing a brand new install.
The 2395 covers the electrical installation condition report, basically the old periodic inspection report.
The 2391 covered both of these.
I believe you would have to complete both the 2394 and 2395 for it to be regarded as the same as the old 2391 course. But this means you could pass the 2394 but fail the 2395 and would only have to resit the 2395 again. Making it slightly easier than having to resit the whole thing again like you would have had to with the 2391.
The colleges are ripping you off in my opinion, their charging you twice for the two new courses when their really the old 2391 course you used to only have to pay once for. But such is life!
The 2394 exams are: 1 online exam (40 multi choice questions closed book), 1 written exam completed at college 3 times a year with city and guilds representives present (2 or 2.5 hours long closed book) and 4 practical exam completed at college (insulation resistance, earth loop impedance, departures and inspection and testing of a test rig)
The 2395 exams are: 1 online exam (40 multi choice questions closed book), 1 written exam completed at college 3 times a year with city and guilds representives present (not sure how long closed book) and 2 practical exam completed at college (departures and electrical installation condition report of a test rig)
If you have completed the online exam on the 2394 course you wont have to do it again in the 2395. The written exams are obviously different though, relating to the course your doing.
I couldn't find much info about the courses when I was looking to start the course probably because their new so hopes this helps.