Why discount overloading because the Neutral burned? Same current through both.It’s usually down to a poor or loose termination of the supply or load cable.
Stranded cables loosen within their terminals easily if the switch plate is moved around too much.
As it’s the neutral terminals that have burnt, we can probably discount overloading.
Go Crabtree or go home imo.
The switch has a face![]()
Not a happy face…
Not a happy face…
i use these good quality and twin screw terminals 50 amp, when making the cables off bring the cables in from the top center making sure you can pull and push them in and out twist the cores with pliers otherwise they will just splay out when screwed in leaving half the strands loose so reducing the current carrying capacity of the cableive never had one burn out that i have fitted in umpteen years and replaced plenty that others have fitted poorly
https://www.superlecdirect.com/6087...CFqBwCf5or79ta27zkl9zLa_AgaScbTkaAlFUEALw_wcB