Deals with all aspects of safety such as electrical, thermal and mechanical aspects. This part of IEC 61558 applies to fixed single-phase air-cooled (natural or forced) associated transformers (incorporated or not) used in the ignition system of gas and oil burners, having a rated supply voltage not exceeding 1 000 V a.c. and a rated frequency not exceeding 500 Hz. The rated output current does not exceed 500 mA a.c. This part 2-3 is intended to be used in conjunction with IEC 61558-1. It has the status of a group safety publication in accordance with IEC Guide 104.