SELV

The use of extra-low voltage (ELV) in an electrical circuit is one of several means to provide protection against electrical shock. The International Electrotechnical Commission and its member organizations define an ELV circuit as one in which the electrical potential of any conductor against earth (ground) is not more than either 50 volts RMS (70 volts peak) for alternating current, or 120 volts for direct current.
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