{"id":252069,"date":"2024-10-19T16:38:12","date_gmt":"2024-10-19T16:38:12","guid":{"rendered":"https:\/\/pdfstandards.shop\/product\/uncategorized\/bs-en-60947-4-32000a22011\/"},"modified":"2024-10-25T11:56:42","modified_gmt":"2024-10-25T11:56:42","slug":"bs-en-60947-4-32000a22011","status":"publish","type":"product","link":"https:\/\/pdfstandards.shop\/product\/publishers\/bsi\/bs-en-60947-4-32000a22011\/","title":{"rendered":"BS EN 60947-4-3:2000+A2:2011"},"content":{"rendered":"

This part of IEC 60947 applies to a.c. 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.<\/p>\n

As controllers, they may be used to reduce the amplitude 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.<\/p>\n

They may include a series mechanical switching device and are intended to be connected to circuits, the rated voltage of which does not exceed 1 000 V a.c.<\/p>\n

This standard characterizes controllers and contactors for use with or without bypass switching devices.<\/p>\n

The semiconductor controllers and contactors dealt with in this standard are not normally intended to interrupt short-circuit currents. Therefore, suitable short-circuit protection (see 8.2.5) should form part of the installation but not necessarily of the controller itself.<\/p>\n

In this context, this standard gives requirements for semiconductor controllers and contactors associated with separate short-circuit protective devices.<\/p>\n

This standard does not apply to<\/p>\n