This European Standard specifies the requirements, performance criteria and testing procedures for PS to be used as part of Intrusion and Hold up Alarm Systems. The PS will either be an integral part of an I&HAS component or stand-alone. 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 CIE. This European 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 European Standard EN 50131-1, Alarm Systems Intrusion and Hold-Up Systems Part 1: System requirements. Requirements are also given for four environmental classes covering applications in indoor and outdoor locations. This standard covers: a) mandatory functions which will be provided on all PS, and b) optional functions which may be provided. This European Standard does not deal with requirements for compliance with EC regulatory Directives, such as the EMC Directive, Low Voltage Directive, etc. except that it specifies the equipment operating conditions for EMC susceptibility testing as required by EN 50130-4. Other functions associated with I&HAS not specified in this standard may be provided. Such functions will not affect the requirements of any mandatory or optional functions.