IEC <br/><br/>
IEC / TRF: 60255-121-2014-03; Measuring relays and protection equipment - part 121: Measuring relays and protection equipment Part 121; Funcational requirements for distance protec 

 - 1.0 
 - Geneva  IEC  2014 
 - 302+4 
<br/><br/><label>Universal Decimal Class. No.: </label> /