scope:

This standard applies, in the conditions set out below, to convertors intended for service on single-phase rolling stock supplied with current of any rated frequency between 15 Hz and 60 Hz. The standard is restricted to convertors where semiconductor reverse blocking triode thyristors or a combination of reverse blocking triode thyristors and semiconductors rectifier diodes are used, but it may also be applied for convertors with bidirectional thyristors in so far as applicable. The term: "thyristor" is used as an abbreviation for "reverse blocking triode thyristor". It applies only to single-phase convertors in which the commutating voltage is supplied by the system. It has been drawn up for convertors supplying vehicle traction circuits. In principle, it also applies to convertors provided for feeding the auxiliary services on these vehicles. It can also be applied to convertors for dual frequency vehicles and to a.c. switches if these form a part of static convertor equipment; details of such application are determined by agreement between user and manufacturer.