1. 
   Extra-low voltage
   Extra-low voltage (ELV) in electricity supply, is one of several means to protect 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 t...
   Found op http://en.wikipedia.org/wiki/Extra-low_voltage
   
   
2. 
   extra-low voltage
   voltage not exceeding the relevant voltage limit of band I specified in IEC 60449
   Found op http://www.electropedia.org/iev/iev.nsf/display?openform&ievref=826-12-30
   
   

Tip: double click on a word to show its meaning.