BAS EN 50274:2007

This standard applies to low-voltage switchgear and controlgear assemblies with a rated voltage not exceeding AC 1 000 V or DC 1 500 V. It sets out the requirements for the provision of additional features to provide protection against electric shock from direct contact with hazardous live parts only for skilled and instructed persons when they are required to manually actuate devices within the assembly and where a level of protection for the operating face of not less than IPXXB cannot be achieved. These devices are those only accessible via a door or cover requiring a key or tool to open it or in an assembly located in an area set apart and where the access to that area is restricted solely to skilled or instructed persons. This standard does not apply to – manually operated devices and their locations where access is available to ordinary persons, – low-voltage switchgear and controlgear assemblies where the operating voltage does not exceed AC 50 V or DC 120 V and there is protective separation, in accordance with EN 61140, between these circuits and any other circuits, NOTE Voltages generated by means of auto-transformers, potentiometers, semiconductor components etc. do NOT meet these requirements. – low-voltage switchgear and controlgear assemblies where protection of persons is provided by limitation of steady-state touch current or charge in accordance with EN 61140.