问题依据:
英国BS7671-2008的526.8.2规定:Soldering (tinning) of the whole conductor end of multiwire, fine wire and very fine wire conductors is not permmited if screw terminals are used.
In order to avoid inappropriate separation or spreading of individual wire or multiwire, fine wire or very fine wire conductors, suitable terminals shall be used or the conductor ends shall be suitably treated.