This European Standard specifies minimum requirements for earthing networks and connections (bonds) in buildings in which information technology equipment is intended to be installed to protect that equipment and interconnecting cabling from electrical hazards. Additionally this European Standard specifies requirements and provides recommendations for earthing networks and connections (bonds) in order for the information technology installation to achieve a)reliable signal reference, b)adequate immunity from electromagnetic interference carried by the earthing network. The requirements of this European Standard are applicable to all types of buildings ranging from residential to large commercial and industrial premises. Operator buildings are addressed by ETSI EN 300 253. This European standard specifies an earthing and bonding configuration that is appropriate to specific mains and other power supply distribution systems. NOTEFor the purposes of this European Standard bonding networks are connected to earth and therefore create an earthing network. This European Standard does not: 1)apply to power supply distribution of voltages over AC 1 000 V; 2)address the specific requirements for telecommunication centres (operator buildings); these are specified in ETSI EN 300 253. Safety requirements for power supply installation are outside the scope of this European Standard and are covered by other standards and regulations. However, information given in this European Standard may be of assistance in meeting these standards and regulations.