The scope of prEN 378-1:2007 is applicable. This European Standard specifies requirements for safety and environmental aspects in relation to operation, maintenance, repair of refrigerating systems and the recovery, reuse and disposal of all types of refrigerant, refrigerant oil, heat transfer medium, refrigerating system and part thereof. These requirements are intended to minimise risks of injury to persons and damage to property and the environment resulting from improper handling of the refrigerants or from contaminants leading to system breakdown and resultant emission of the refrigerant. Certain clauses and subclauses of this European Standard are not applicable to unit systems self contained systems and systems built on site which operate with charges of refrigerant up to 3 kg of refrigerant. These subclauses are 4., 4., 4.2, 4.3, 5. to 5., 5.2, 5.3.1, 5.3.3 and 6.6. For these systems, the necessary maintenance has to be described in the instruction manual and should repairs be necessary, contact the nearest authorised repair service centre.