Suburban electric multiple unit (EMU) enters into service in Croatia September 7, 2011 | Europe News A prototype of a 25 kV 50 Hz suburban electric multiple unit (EMU) has entered into service in Zagreb. The EMU has been developed jointly by Koncar and TZV Gredelj. The four-car articulated unit h... This content is available to only subscribers. Username or E-mail Password Remember Me Forgot Password