Brazil’s National Institute of Metrology, Standardization and Industrial Quality (INMETRO) issued Portaria No. 118/2026 on April 27, 2026, mandating a revised short-circuit test requirement for industrial circuit breakers rated ≥63 A sold in Brazil. The update directly affects manufacturers, exporters, and certification service providers engaged in the low-voltage power distribution equipment sector — particularly those supplying to Brazilian utilities, infrastructure projects, and industrial OEMs.

Event Overview

On April 27, 2026, INMETRO published Portaria No. 118/2026, an urgent amendment requiring all industrial circuit breakers with rated current ≥63 A placed on the Brazilian market to comply with the new double-exponential impulse current waveform specified in Annex Q of IEC 60947-2:2025 (τ₁ = 10 μs, τ₂ = 700 μs) for short-circuit testing. Compliance becomes mandatory effective August 1, 2026. Affected products must undergo type testing at INMETRO-recognized laboratories, and existing type test reports must be updated accordingly.

Industries and Stakeholders Affected

Direct Exporters and Trade Enterprises

Exporters of industrial circuit breakers from China and other non-Brazilian countries are directly affected because the amendment applies to all products placed on the Brazilian market. Non-compliant units risk rejection at customs or post-market withdrawal. Impact manifests in delayed shipments, retesting costs, and potential contract renegotiations where compliance timelines were not previously stipulated.

Manufacturers and Original Equipment Manufacturers (OEMs)

Manufacturers producing ≥63 A industrial circuit breakers must revise their design validation and production testing protocols. The new waveform differs significantly from prior test profiles (e.g., standard 4.5/45 μs or 8/20 μs surges), potentially affecting arc interruption performance evaluation. Product redesign is not required unless existing designs fail the new test — but verification is mandatory.

Certification and Testing Service Providers

Laboratories accredited by INMETRO — or seeking such recognition — must calibrate and validate their impulse generators to reproduce the τ₁=10 μs / τ₂=700 μs waveform per Annex Q. This involves traceable waveform verification, uncertainty assessment, and documentation aligned with INMETRO’s technical requirements. Labs not yet equipped for this waveform may face capacity constraints ahead of the August 2026 deadline.

Supply Chain and Distributors

Distributors and channel partners holding inventory of pre-August 2026 certified breakers must verify whether existing stock carries valid test reports referencing IEC 60947-2:2025 Annex Q. INMETRO does not grandfather legacy certifications; therefore, unsold inventory without compliant reports may require retesting or relabeling before further distribution.

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

Monitor official INMETRO communications for implementation guidance

Portaria No. 118/2026 is an enabling regulation — detailed technical instructions (e.g., acceptable tolerance bands for τ₁/τ₂, reporting format, lab accreditation criteria) are expected in subsequent normative documents. Stakeholders should subscribe to INMETRO’s official notices and track updates via the INMETRO website.

Identify and prioritize product families subject to the ≥63 A threshold

The requirement applies only to industrial circuit breakers with rated current ≥63 A. Companies should audit their active SKUs and export portfolios to isolate affected models — especially those previously certified under older editions of IEC 60947-2 (e.g., 2016 or 2020). Low-current devices (<63 A) and domestic-use miniature circuit breakers (MCBs) remain outside this scope.

Engage INMETRO-recognized labs early to secure test slots

Lead times for Annex Q testing are expected to increase as demand rises ahead of the August 1, 2026 deadline. Exporters and manufacturers should contact accredited labs now to confirm capability, schedule pre-tests, and align documentation (e.g., updated test plans, product schematics, and calibration records).

Review contracts and delivery terms for compliance liability clauses

Commercial agreements involving Brazilian buyers should be reviewed for clauses assigning responsibility for regulatory compliance, retesting costs, or delivery delays due to certification updates. Where silent, proactive alignment with customers on timelines and evidence submission (e.g., new test reports, INMETRO registration updates) is advisable.

Editorial Perspective / Industry Observation

Observably, this amendment reflects INMETRO’s broader alignment with the latest edition of IEC 60947-2 — particularly its enhanced focus on real-world short-circuit stress profiles. Analysis shows the τ₁=10 μs / τ₂=700 μs waveform better simulates high-energy fault currents observed in modern industrial networks with large capacitor banks or distributed generation. While not a de facto global harmonization step, it signals tightening technical expectations for market access in Brazil — especially for safety-critical power protection equipment. From an industry perspective, this is less a sudden disruption and more a formalized technical escalation already anticipated by standards-aware manufacturers. However, the compressed timeline (just over three months from publication to enforcement) makes operational readiness the immediate differentiator.

Current observation suggests this is primarily a regulatory signal — one that confirms Brazil’s intent to adopt evolving IEC safety benchmarks without transitional allowances. It is not yet a fully implemented outcome across the supply chain, given pending lab readiness and clarification on conformity assessment procedures. Continued monitoring of INMETRO’s technical circulars and laboratory bulletins remains essential.

Conclusion

This amendment underscores that compliance for industrial electrical equipment in Brazil is shifting from static certification to dynamic, standards-updated conformity. For stakeholders, it is best understood not as an isolated regulatory change, but as a marker of increasing technical rigor in Latin American markets — where alignment with latest IEC editions is becoming a prerequisite, not an option. Preparedness hinges on targeted action — not broad speculation — and centers on verifying product scope, engaging qualified labs, and aligning contractual and logistical planning with the August 1, 2026 enforcement date.

Information Sources

• INMETRO Portaria No. 118/2026, published April 27, 2026
• IEC 60947-2:2025, Annex Q (Impulse current test with double-exponential waveform)

Note: Implementation details — including acceptable waveform tolerance, lab accreditation criteria, and transitional provisions for pending applications — are pending official INMETRO technical guidance and remain under observation.