Before the introduction of BS 317, GH Scholes Ltd ( Wylex ) introduced ( in 1926 ) an alternative three-pin plug . in three sizes, 5 A, 10 A and 15 A with a round earth pin and rectangular live pins, a fused 13 A version of this continued to be available after the introduction of BS 1363, illustrating that BS 546 was not used exclusively at any time.
