scope:

This International Standard gives specifications applicable to all transformers for resistance welding equipment with or without connected rectifier. The following types are included: ? single-phase transformers for alternating welding current, typically operating at 50 Hz or 60 Hz; ? single-phase transformers with connected rectifier typically operating at 50 Hz or 60 Hz; ? single-phase inverter welding transformer with connected rectifier typically operating at 600 Hz to 2 kHz; ? three-phase transformers with connected rectifier typically operating at 50 Hz or 60 Hz; ? three-phase low frequency converter equipment, typically operating at 5 Hz to 16 Hz. NOTE 1 Typical operating frequencies are given for information only and are not exclusive. For the purposes of this International Standard, a transformer can refer to the transformer alone or combined with other components such as a rectifier, as listed above. This International Standard applies to transformers built to protection class I or II according to IEC 61140. NOTE 2 This International Standard provides fundamental requirements that can be supplemented by other resistance welding transformer standards e.g. ISO 22829 and ISO 10656.