The gas appliance directive and its implications on control systems

The Gas Appliance Directive, 90/396/EEC, is one of the “new-approach” Directives, which rather than specifying detailed technical requirements for products, sets out essential requirements only. The implementation of the Directive is largely through harmonised standards drawn up within the EEC by either CEN (mainly mechanical items) or CENELEC (mainly electrical items). However, manufacturers can propose other means of compliance to the Notified Bodies, (the Authorities appointed by Governments to ensure compliance), who have discretion to accept such alternatives. The Essential Requirements of the Directive set out basic, generic requirements which the implementing Standards need to interpret into usable requirements. These can subsequently be incorporated into the Conformity Assessment process. Successful completion of the assessment will help to ensure the CE-marking of the appliance, and its consequent acceptability in the European market-place. Most of the essential requirements of the Directive are concerned with safety and construction of the appliances. Amongst these are several which have strong implications for the design of controls