Overview
IEC 60755-1:2022 is a Group Safety Publication from the International Electrotechnical Commission (IEC) that provides requirements, recommendations and background information for drafting standards for residual current operated protective devices for DC systems (DC‑RCDs). It defines intended functions - detection of residual current, comparison to a reference value, and contact opening when that value is exceeded - and sets out the safety framework for devices used in DC applications such as photovoltaic (PV) systems, data/telecom centres and electric vehicle (EV) charging.
This Part 1 document is primarily intended for use by technical committees preparing product safety standards (in accordance with IEC Guide 104 and ISO/IEC Guide 51). It is to be used in conjunction with IEC 60755 and IEC 60364 and is based on information from the IEC 60479 series.
Key topics and requirements
- Scope and definitions: Clarifies what constitutes a DC‑RCD and the functional requirements (detect, compare, trip).
- Rated values and limits: Guidance on rated residual operating currents (notably the 80 mA reference for additional protection) and rated voltages (up to 220 V DC single‑pole or 440 V DC two‑pole for the stated applications).
- Classification and characteristics: Device classes, operating characteristics, and resistance to unwanted tripping from switching transients or induced surges.
- Marking and product information: Requirements for labels and technical documentation to support safe installation and use.
- Conditions for installation and operation: Environmental, system‑connection and service conditions appropriate for DC systems (TN, TT and, under specific conditions, IT systems).
- Construction and safety tests: Requirements and test methods covering mechanical and electrical construction, break times, tripping current limits, short‑circuit tests and ageing of electronic components.
- Electromagnetic compatibility (EMC) and immunity: Incorporates relevant EMC test standards (IEC 61000‑4 series, IEC 61543) including ESD, radiated immunity, surge, conducted disturbances and voltage dips/interruptions.
Applications and who uses it
- Technical committees and standards developers drafting product safety standards for DC residual current devices.
- System designers and safety experts (PV systems, EV charging infrastructure, data centres, telecom) who need to understand the safety expectations embedded in standards development.
- Note: IEC 60755-1:2022 is not intended as a stand‑alone certification standard for manufacturers or certification bodies, but those stakeholders may reference it as a normative guide when aligning product requirements with system safety standards.
Related standards
Keywords: IEC 60755-1:2022, DC‑RCD, residual current operated protective devices, DC systems, safety requirements, testing, EMC, photovoltaic, EV charging.
Open preview (PDF)General safety requirements for residual current operated protective devices - Part 1: Residual current operated protective devices for DC systems
