EVS-EN 60947-4-3:2001/A1:2007

This standard applies to semiconductor non motor load controllers and contactors intended for performing electrical operations by changing the state of a.c. electric circuits between the ON state and the OFF state. Typical applications are given in table 2. As controllers, they may be used to reduce the amplitue of the r.m.s. a.c. voltage on the load terminals from that of the applied voltage - either continuously or for a specified period of time. The half-wave period of the a.c. wave form remains unchanged from that of the applied voltage.