1.1 The scope of prEN 378-1:1999 is applicable. 1.2 This Part 3 of the European Standard is applicable to the installation site (design of plant space and services) and personal protective equipment. 1.3 This Part 3 is not applicable to unit systems and self-contained systems which operate with charges of refrigerant up to: - 2,5 kg of group L1 refrigerant; - 1,5 kg of group L2 refrigerant; and - 1,0 kg of group L3 refrigerant.