IEC 62955:2026 Published: RCMs Now Require DC-Side PV Compliance

On 14 May 2026, the International Electrotechnical Commission (IEC) officially published IEC 62955:2026, Residual Current Monitoring Devices — Particular Requirements for Photovoltaic System DC-Side Applications. This revision introduces mandatory testing for DC-side arc-fault response time (≤0.3 s) and operational stability across an extended temperature range (−40 °C to +85 °C). The standard directly affects market access for residual current monitoring (RCM) modules used with TOPCon and HJT photovoltaic systems in the EU, Australia, and Southeast Asia — making it critical for manufacturers, exporters, and system integrators serving these regions.

Event Overview

The International Electrotechnical Commission (IEC) released IEC 62955:2026 on 14 May 2026. The standard specifies particular requirements for residual current monitoring devices (RCMs) applied to the DC side of photovoltaic systems. It newly mandates two technical criteria: (1) maximum DC arc-fault response time of ≤0.3 seconds; and (2) verified functional stability under ambient temperatures from −40 °C to +85 °C. The standard applies to RCMs integrated with high-efficiency PV modules such as TOPCon and HJT. Leading Chinese RCM manufacturers have initiated expedited UL/IEC dual certification processes in response.

Impact on Specific Industry Segments

Direct Exporters and Trade Enterprises
These entities face revised conformity assessment requirements when shipping RCMs to the EU, Australia, and Southeast Asian markets. Compliance with IEC 62955:2026 is now a prerequisite for CE marking (EU), SAA approval (Australia), and relevant national safety certifications (e.g., Singapore’s PSB, Thailand’s TISI). Non-compliant units may be rejected at customs or subject to post-market surveillance actions.

Manufacturers of RCM Hardware and Embedded Modules
Producers supplying Photon Metrics–type monitoring solutions must redesign or revalidate existing DC-side RCM products to meet the new response-time and thermal-stability thresholds. Firmware logic, sensor bandwidth, and thermal management architecture may require revision. Certification timelines will extend due to additional test cycles, especially low-temperature arc-fault validation.

Photovoltaic System Integrators and EPC Contractors
Integrators specifying RCMs for utility-scale or commercial rooftop PV projects must now verify third-party test reports confirming compliance with IEC 62955:2026. Procurement specifications and tender documents issued after mid-2026 are expected to reference this standard explicitly — potentially disqualifying legacy RCM models not tested per the 2026 edition.

What Relevant Enterprises or Practitioners Should Focus On and How to Respond

Monitor official adoption timelines and transitional arrangements

Although IEC 62955:2026 is published, national standards bodies (e.g., CENELEC, Standards Australia, SAC) may issue formal adoptions with defined grace periods. Enterprises should track publication dates of harmonized standards (e.g., EN IEC 62955) and any grandfathering clauses allowing continued use of pre-2026 certified units during installation or commissioning.

Prioritize verification for high-volume export destinations

Given limited testing capacity and extended lead times, manufacturers should first validate RCM models destined for the EU and Australia — where regulatory enforcement is most mature. Southeast Asian markets may follow with phased implementation; however, early alignment reduces rework risk if regional regulators adopt the standard without modification.

Distinguish between certification readiness and field deployment readiness

Obtaining a test report or certificate does not automatically ensure seamless integration. Field-level interoperability with inverters, string-level optimizers, and SCADA platforms must be confirmed separately. Enterprises should initiate joint validation protocols with key inverter OEMs before full-scale production ramp-up.

Update technical documentation and supply chain communications

Manufacturers must revise datasheets, declaration of conformity statements, and user manuals to reflect IEC 62955:2026 compliance. Distributors and channel partners should receive updated technical training materials highlighting the new DC-side requirements — particularly the distinction between AC-side RCMs (covered by IEC 62423) and this dedicated DC-side standard.

Editorial Perspective / Industry Observation

Observably, IEC 62955:2026 signals a structural shift toward stricter safety governance for PV DC-side components — moving beyond generic residual-current protection into application-specific performance assurance. Analysis shows this is less an isolated update and more a foundational step enabling future grid codes and fire-safety regulations that rely on rapid DC arc detection. From an industry perspective, the inclusion of −40 °C to +85 °C stability suggests growing recognition of real-world deployment diversity — especially in desert and high-latitude installations. Current adoption remains at the standard publication stage; enforceable regulatory status depends on national transposition, meaning the practical impact is still unfolding rather than fully realized.

Conclusion
IEC 62955:2026 establishes the first internationally harmonized safety benchmark for RCMs deployed on the DC side of photovoltaic systems. Its introduction reflects increasing technical granularity in PV system safety regulation — particularly around fault detection speed and environmental robustness. For stakeholders, the standard is best understood not as an immediate compliance deadline, but as a binding technical reference point shaping product development, certification strategy, and cross-border market access planning over the next 12–24 months.

Information Sources
Main source: International Electrotechnical Commission (IEC), Publication Record for IEC 62955:2026 (released 14 May 2026).
Note: National adoption timelines, enforcement mechanisms, and transitional provisions remain pending confirmation by regional standards bodies and market surveillance authorities — these require ongoing observation.