Overview
IEC TR 63139:2018 is a Technical Report from IEC TC 34 (Lamps and related equipment) that explains insulation coordination for modern lighting technologies. It clarifies how to treat the mathematical addition of working voltages, insulation between circuits, and the use of Protective Extra Low Voltage (PELV) when assessing insulation requirements in luminaires and controlgear-particularly for LED light sources and controllable products. The report supports practical decisions on creepage distances, clearances and circuit insulation when a first-failure condition occurs.
Key topics and requirements
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Mathematical addition of working voltages
- Provides a reproducible method to combine supply and output working voltages for insulation design when basic insulation within controlgear fails.
- Covers combinations such as AC/AC (same or different frequency), AC/DC and DC/DC scenarios and refers to specific calculation approaches (see Table 1 of the TR).
- Rationale: direct measurement of fault voltages is often impractical, so conservative mathematical addition is used for design and testing.
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Insulation between circuits
- Explains required insulation levels between active parts and accessible conductive parts based on controlgear input/output insulation classification and luminaire insulation class (referencing IEC 60598-1 and IEC 61347-1 tables).
- Describes failure scenarios (input/output failure, earth/equipotential bonding faults, insulation failures between outputs and conductive parts) and their implications for protective requirements.
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Use of PELV
- Describes how PELV can increase immunity and reliability in electronic circuits used with LEDs and details safety consequences.
- Discusses PELV characteristics and requirements in relation to SELV and touch-current/protective conductor considerations.
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Insulation between LV supply and control line conductors
- Highlights the importance of separating low-voltage supply and control conductors in complete installation systems to maintain safety under fault conditions.
Practical applications - who uses this standard
- Lighting manufacturers and controlgear designers assessing creepage distances and clearances for LED luminaires.
- Safety and compliance engineers preparing designs or test plans against IEC 60598-1 and IEC 61347-1 requirements.
- Test laboratories evaluating insulation under simulated fault conditions.
- Standards committees and product certification bodies updating requirements for controllable lighting products.
Related standards
Keywords: IEC TR 63139:2018, insulation coordination, mathematical addition of working voltages, PELV, TC 34 standards, LED lighting, controlgear, creepage distances, clearances, insulation between circuits.