What is BS EN 62870 - Safety secondary circuits in series circuits about?
Electrical installation is a cabling and associated devices such as switches, distribution boards, sockets, and light fittings in a structure. BS EN 62870 specifies protective provisions for the operation of lamp systems powered by series circuits in aeronautical ground lighting. The protective provisions described here refer only to secondary supply systems for loads that are electrically separated from the series circuit.
BS EN 62870 specifies the level of SELV, and alternatively PELV, under consideration of additional personnel protection during work on live secondary circuits by electrically skilled persons. BS EN 62870 also covers the special operational features of aeronautical ground lighting and addresses the level of training and the requirements for maintenance procedures detailed in IEC 61821.
Who is BS EN 62870 - Safety secondary circuits in series circuits for?
BS EN 62870 on safety secondary circuits in series circuits is useful for:
- Safety bodies
- Electric lighting installers
- Electricians
- Electrical engineers
Why should you use BS EN 62870 - Safety secondary circuits in series circuits?
The input voltage to the series circuit is constantly adjusted by the constant current regulator to maintain the series circuit current irrespective of the variations in the load. The properties and characteristics of the constant current regulators are provided in IEC 61822. Since one or more earth faults of varying resistance to earth, may be present, the touch voltage to earth may assume any value up to the maximum series circuit input voltage depending on the location of the earth fault and the equipment installed in the series circuit. Therefore, when determining the dielectric strength against earth potential it is usual to take the maximum series circuit input voltage. Such peculiarities of the series circuit have been considered in the requirements for lamp systems in BS EN 62870.
Since there are only a few effective safety features available for personnel protection in series circuit technology the protective measure “Safety extra-low voltage (SELV)” and “Protective extra-low voltage (PELV)” is applied in BS EN 62870 for the supply of lamp systems. The requirements and tests are intended to set a specification framework for system designers, users, and maintenance personnel to ensure safe and economic use of electrical systems in installations for the beaconing of aerodromes. BS EN 62870 complements existing IEC Airfield-Ground- Lighting (AGL) standards and can be used as a design specification.