![]() ![]() Types Separated or safety extra-low voltage (SELV) These systems should still fall under the SELV / PELV (ELV) safety specifications. Lower voltage can apply in wet or conductive conditions where there is even greater potential for electric shock. In more arduous conditions 25 volts RMS alternating current / 60 volts (ripple-free) direct current can be specified to further reduce hazard. Modern battery operated hand tools fall in the SELV category. Some types of landscape lighting use SELV / PELV (extra-low voltage) systems. SELV, PELV, FELV, are distinguished by various safety properties, supply characteristics and design voltages. These can be supplied using sources including motor / fossil fuel generator sets, transformers, switched PSU's or rechargeable battery. The IEC and IET go on to define actual types of extra-low voltage systems, for example separated extra-low voltage (SELV), protected extra-low voltage (PELV), functional extra-low voltage (FELV). The International Electrotechnical Commission (IEC) and the UK IET (BS 7671:2008) define an ELV device or circuit as one in which the electrical potential between two conductors or between an electrical conductor and earth (ground) does not exceed 50 V AC or 120 V DC (ripple free). There are various standards that define extra-low voltage. ![]() ![]() IEC voltage rangeĮxtra-low voltage ( ELV) is an electricity supply voltage and is a part of the Low voltage band in a range which carries a low risk of dangerous electrical shock. Low voltage installations for low voltage devices. ![]()
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