the use of SELV is required in some instances in special locations such as bathrooms, saunas, swimming pool areas etc.
SELV For example, Extractor fans for bathrooms fed from and external 230/12v transformer or 12v IP rated downlights fed from a single transformer or multiple transformers within the ceiling/ roof space. A SELV circuit must not be earthed at the SEPERATE ELV end of the circuit.
PELV is much the same as SELV but it "protected" or double insulated for extra "Basic" protection. PELV circuits can be connected to earth and the transformers within the equipment are double insulated from each other.
FELV - Functional extra low voltage circuits are basically extra low voltage circuits that do not fulfill the requirments of SELV or PELV.
