IEC 60255-26-2013 pdf download

IEC 60255-26-2013 pdf download.Measuring relays and protection equipment – Part 26: Electromagnetic compatibility requirements.
4 Definition of environmental levels
4.1 General
The environmental levels shall be selected in accordance with the most realistic installation and environmental conditions in which the EUT is expected to operate.
Based on common installation practices, the recommended selection of test levels is the following:
4.2 Zone A, severe electrical environment
The installation is characterized by the following attributes:
• no suppression of electrical fast transientslbursts in the power supply and control and power circuits which are switched by relays and contactors;
• no separation of the industrial circuits from other circuits associated with environments of higher severity levels:
• no separation between power supply, control, signal and communication cables;
• use of common multi-core cables for control and signal lines.
The outdoor area of industrial process equipment, where no specific installation practice has been adopted, of power stations, open-air HV substation switchyards and gas insulated switchgear may be representative of this environment.
4.3 Zone B, typical electrical environment
The installation is characterized by the following attributes:
• no suppression of electrical fast transients/bursts in the power supply and control circuits which are switched by relays (no contactors);
• poor separation of the industrial circuits from other circuits associated with environments of higher severity levels:
• dedicated cables for power supply, control, signal and communication lines;
• poor separation between power supply, control, signal and communication cables;
availability of earthing system represented by conductive pipes, ground conductors in the cable trays (connected to the protective earth system) and by a ground mesh.
The area of industrial process equipment, the power plants and the relay room of open-air HV substations may be representative of this environment.
5 Emission
5.1 Emission enclosure
Conditional testing procedure
• The highest internal source of an EUT is defined as the highest frequency generated or used within the EUT or on which the EUT operates or tunes.
• If the highest frequency of the internal sources of the EUT is less than 108 MHz, the measurement shall only be made up to I GHz.
• If the highest frequency of the internal sources of the EUT is between 108 MHz and 500 MHz, the measurement shall only be made up to 2 GHz.
• If the highest frequency of the internal sources of the EUT is between 500 MHz and I GHz, the measurement shall only be made up to 5 GHz.
• If the highest frequency of the internal sources of the EUT is above I GHz, the measurement shall be made up to 5 times the highest frequency or 6 GHz, whichever is less.
5.2 Emission auxiliary power supply port See Table 2.IEC 60255-26 pdf download.