MT 25 - TC 10/MT 25

IEC 60567:2023 deals with the techniques for sampling free gases from gas-collecting relays from power transformers. Three methods of sampling free gases are described. The techniques for sampling oil from oil-filled equipment such as power and instrument transformers, reactors, bushings, oil-filled cables and oil-filled tank-type capacitors are no longer covered by this document, but are instead described in IEC 60475:2022, 4.2. Before analysing the gases dissolved in oil, they are first extracted from the oil. Three basic methods are described, one using extraction by vacuum (Toepler and partial degassing), another by displacement of the dissolved gases by bubbling the carrier gas through the oil sample (stripping) and the last one by partition of gases between the oil sample and a small volume of the carrier gas (headspace). The gases are analysed quantitatively after extraction by gas chromatography; a method of analysis is described. Free gases from gas-collecting relays are analysed without preliminary treatment.

Applies to capacitors according to IEC 60831-1 and gives the requirements for ageing test, self-healing test and destruction test for these capacitors.

Contains specific requirements for the construction and testing of electrical apparatus with the type of protection flameproof enclosure "d", intended for use in explosive gas atmospheres. The contents of the corrigendum of February 2007 have been included in this copy.