This part of the IEC 62642 series specifies the requirements, performance criteria and testing procedures for power supplies (PS) to be used as part of Intrusion and Hold up Alarm Systems (I&HAS). The PS shall either be an integral part of an I&HAS component or standalone. The control functions of the PS may be incorporated as part of the PS device, or may be provided by another I&HAS component e.g. a control and indicating equipment (CIE). This International Standard is not applicable when the PS requirements for I&HAS components are included within the relevant product standard. The requirements correspond to each of the four security grades given in the IEC 62642-1. Requirements are also given for four environmental classes covering applications in internal and outdoor locations. This standard covers mandatory functions which shall be provided on all PS and optional functions which may be provided. Other functions associated with I&HAS not specified in this standard may be provided. Such functions shall not affect the requirements of any mandatory or optional functions