Group A : Persons using electrical equipment/installations related to technical electrical insurance classified in Group I, II, III, IV and V
Group B: Installers and maintainers of equipment; Low voltage installations and wiring,(ITU)
Group C: Authorized installers for airlines or underground with high voltage up to 30 KV (including), Type 1
Group D: Authorized airline or underground installers with high voltage above 30 kV, Type 2
Group E: Authorized installers for high voltage wiring with nominal voltage not greater than 30 kV, AT1;
Group F: Authorized installers For high voltage wiring without voltage limits, AT2