All this burnt happened because you are drawing too high amp from the wall and the socket can't withstand the high current, it's better to go with 10amp minimum, I used to use a 5 amps socket and this was what happened too
I could smell the foul odour from a block away, glad I caught this real quick, the wall sockets also took some damage
It was 16 amp rated connector with 20 amp rated electrical cable and I was pulling at most 10 amp
The multitap is also rated 16 amp...
I'm not sure which one burned however but it could also just had been bad connections causing frequent sparks.
Trust me, I was not pulling too much for what it was supposed to support... I was pulling too much for what it could deliver however :p
It held 3 years and just started recently to burn.
Just bought higher quality connectors rather than the cheap one I used and in any case, I wont be pulling more than 7A once I have splitted my rigs.