BS 7484:1991

This standard BS 7484:1991 Guide to electromagnetic environment for low-frequency conducted disturbances and signalling in public power supply systems is classified in these ICS categories:

• 33.100.10 Emission
• 91.140.50 Electricity supply systems

This section of IEC 1000-2 is concerned with conducted disturbances in the frequency range up to 10 kHz with an extension for mains signalling systems. Separate sections give numerical compatibility levels for different system voltage levels.

This section does not deal with the application of compatibility levels to assess, for example, the permissible interference emission from specific items of equipment or installations, because other system parameters, such as its impedance as a function of frequency, have also to be considered. Furthermore, it does not prejudge the specification of immunity levels by the product committees but merely provides a guide.

The disturbance phenomena considered are:

• harmonics;

• inter-harmonics;

• voltage fluctuations;

• voltage dips and short supply interruptions;

• voltage unbalance;

• mains signalling;

• power frequency variation;

• d.c. components.

The object of this section is to give information on the various types of disturbances that can be expected on public power supply systems. It is a reference document for those associated parts that give values of compatibility level.