Overview
IEC 62561-3:2023 - "Lightning protection system components (LPSC) - Part 3: Requirements for isolating spark gaps (ISGs)" - is the third edition international standard that specifies requirements and test procedures for isolating spark gaps (ISGs) used in lightning protection systems (LPS). This 2023 edition cancels and replaces IEC 62561-3:2017 and introduces technical revisions including alignment with the latest ISO 22479 for humid sulphurous atmosphere treatment and a new normative Annex D on applicability of previous tests.
ISGs provide an indirect bonding method where a direct electrical bond is not permissible for functional reasons. The standard is intended for designers, manufacturers, test laboratories, installers and certifiers working with lightning protection components.
Key Topics and Requirements
- Scope and classification
- Defines ISG use-cases and classification according to lightning-current capability and installation location.
- Environmental requirements and tests
- Corrosion resistance (salt mist, humid sulphurous atmosphere per ISO 22479, ammonia).
- Ultraviolet (UV) resistance for outdoor ISGs.
- Mechanical tests
- Impact and mechanical integrity testing (e.g., pendulum hammer apparatus referenced).
- Electrical tests
- Isolation resistance and rated DC/power-frequency withstand voltages.
- Rated impulse sparkover voltage and lightning current withstand capability (see Table 1 for lightning impulse current parameters).
- Documentation, marking and installation instructions
- Required technical documentation, installation guidance, marking and traceability.
- Electromagnetic compatibility (EMC)
- Requirements ensuring ISGs do not adversely affect or be affected by EMC issues.
- Test reporting
- Structure and content of test reports, including specimen description, test equipment, measured parameters and pass/fail statements.
- Normative annexes
- Annex A: test flowchart; Annex B: detailed corrosion treatments; Annex C: UV tests; Annex D: applicability of previous tests.
Practical Applications and Who Uses This Standard
Typical practical applications where ISGs are specified include:
- Bonding to earth-termination systems of power and telecommunication installations
- Auxiliary earth electrodes for earth-fault devices
- Rail earth electrodes (power and DC railways)
- Measuring earth electrodes in laboratories
- Installations with cathodic protection or stray current systems
- Service entry masts for LV overhead cables and bypassing insulated pipeline couplings
Primary users:
- LPS designers and consulting engineers
- ISG manufacturers and component suppliers
- Independent test laboratories and certification bodies
- Utilities (power, rail), telecom operators, pipeline and industrial asset owners
- Installers and maintenance contractors
Related Standards
- IEC 62305 series (overall lightning protection design)
- ISO 22479 (humid sulphurous atmosphere treatment) - alignment noted in 2023 edition
- National or regional standards for hazardous/explosive atmospheres where additional requirements apply
Keywords: IEC 62561-3, isolating spark gaps, ISG, lightning protection system, LPSC, sparkover voltage, corrosion resistance, UV resistance, lightning current tests.