Testing Lab of Power Supply/ IT / AV Products

IEC 60335 certification is the fundamental safety benchmark for household and similar electrical appliances entering international markets. Developed by the International Electrotechnical Commission (IEC), this family of standards addresses electrical safety, mechanical protection, thermal management and more. To date, over 50 countries have adopted IEC 60335 (or its nationally harmonised versions) as a mandatory or recommended requirement for appliance market access. For manufacturers aiming at global markets, understanding the testing framework and certification pathways of IEC 60335 is a critical step toward compliant market entry.

Framework of the IEC 60335 Standard Series

IEC 60335 is not a single document but a two-tier structure combining a general requirements part (Part 1) and dozens of product-specific parts (Part 2). According to the IEC, the standard “deals with the safety of electrical appliances for household and similar purposes, the rated voltage of the appliances being not more than 250 V for single-phase appliances and 480 V for other appliances,” covering a broad range from kitchen machines to cleaning equipment.

The current mainstream edition is IEC 60335-1:2020 (6th edition), which incorporates amendments AMD1:2021 and AMD2:2023, introducing more complete requirements for battery-operated appliances, software safety evaluation and USB circuit protection. When initiating a certification project, manufacturers must first identify the applicable Part 2 standard, because the particular requirements of Part 2 take precedence over Part 1 general requirements in certification decisions.

Product types and corresponding Part 2 standards

• Refrigerating appliances　IEC 60335-2-24 — covers compression-type refrigerators, freezers
• Microwave ovens　IEC 60335-2-25 — includes microwave leakage limits and door interlock requirements
• Room heaters　IEC 60335-2-30 — covers overheat protection, covering test and other thermal safety items
• Air conditioners and heat pumps　IEC 60335-2-40 — addresses refrigerant safety, pressure vessel protection etc.
• Motor-operated kitchen appliances　IEC 60335-2-14 — covers blenders, juicers, food processors and similar

Key Testing Areas Under IEC 60335

The IEC 60335 testing framework revolves around three dimensions: safety under normal operation, protection under abnormal conditions, and long-term reliability. Below is a breakdown of the most scrutinised test categories and their underlying safety rationale.

Electric strength and insulation testing

The electric strength test (dielectric withstand test) is one of the most fundamental yet frequently overlooked parts of IEC 60335. The standard specifies different test voltage values based on insulation type (basic, supplementary, reinforced) and the appliance’s rated voltage. For reinforced insulation, for example, the test voltage is typically between 3000 V and 4000 V AC (exact value depends on working voltage). In addition to the withstand test, leakage current measurement is equally critical — the standard requires that under normal operating temperature, the earth leakage current of various appliances must not exceed prescribed limits (usually 0.25 mA to 3.5 mA, depending on appliance type and earthing method).

Temperature rise and thermal safety evaluation

The temperature rise test is one of the most time‑consuming and frequently failed items in IEC 60335 certification. The standard sets detailed limits for different components: motor windings, switch contacts, internal wiring insulation and accessible external surfaces each have their own maximum temperature thresholds. Taking accessible surfaces as an example, the allowable temperature rise for metal surfaces is typically 30 K to 45 K (depending on whether the surface is continuously held), while for plastic surfaces the risk of thermal deformation must also be considered. The test is conducted under a severe condition of 1.06 times rated voltage and must run until thermal stability is reached.

Abnormal operation and fault simulation tests

IEC 60335 provides extremely comprehensive coverage of abnormal conditions, a key characteristic that distinguishes it from other safety standards. Typical abnormal test scenarios include: locked-rotor test (motor rotor locked while energised, to check for fire risk), electronic component fault simulation (simulating open-circuit or short-circuit failures of critical electronic components one by one), and thermostat short-circuit test (simulating worst-case condition when the temperature control system fails). These tests have very tight acceptance criteria — even under a single fault condition, the product must not produce flames, molten metal ejection or accessible hazardous live parts.

Mechanical hazard protection and construction compliance

Mechanical safety is another aspect often underestimated by manufacturers within IEC 60335. The standard sets explicit technical criteria for protection against moving parts, enclosure opening dimensions, stability (tilt test), and mechanical strength (drop and impact). For stability, for instance, the appliance must remain upright on a plane inclined at 10°; portable appliances must additionally withstand a drop test onto a hardwood floor from a specified height. Although these mechanical items appear straightforward, they frequently surface as non-conformities in the laboratory — especially in designs where weight distribution has changed during product iteration.

IEC 60335 Certification Process Step by Step

A complete IEC 60335 certification project can be summarized into five core stages. Below is a practical breakdown of the key actions and common bottlenecks at each stage, helping manufacturers plan realistic timelines.

Stage 1: Standard identification and documentation

The first step is to determine the exact IEC 60335-2 standard applicable to the product. Although this sounds simple, it requires precise definition of product functionalities — for example, a microwave oven with grilling function may need to satisfy requirements from both IEC 60335-2-25 and IEC 60335-2-9 (grills). For documentation, manufacturers need to prepare product specifications, circuit schematic diagrams, PCB layout drawings, a list of critical safety components (with their certificates), rating label artwork and the instruction manual. The completeness of documentation directly affects how smoothly testing can be scheduled.

Stage 2: Sample submission and pre‑compliance checks

Standard practice requires 2 to 4 representative samples (the exact number depends on product type and test items). It is advisable to run a round of pre‑compliance testing before the formal test, focusing on high‑risk items such as temperature rise and abnormal operation. Based on experience from multiple home appliance projects, issues discovered at the pre‑screening stage are most often concentrated in insufficient insulation coordination and marginal selection of critical components. Identifying and resolving these early can significantly shorten the formal test duration.

Stage 3: Formal testing and non‑conformity rectification

During the formal test phase, the laboratory executes all test procedures according to the applicable standard. If non‑conformities are found, the manufacturer receives detailed test data and a description of the failure. Rectification efficiency varies widely — structural issues (e.g. enclosure openings exceeding limits) are usually faster to resolve than circuit‑level problems. Maintaining frequent technical communication with the laboratory team during the rectification phase is recommended to focus resources on the correct direction and avoid multiple rounds of re‑testing.

Stages 4–5: Report review, factory inspection and certificate issuance

Once testing is passed, the process moves to report compilation and technical review. For certification schemes that require factory inspection (such as the CB scheme), auditors will evaluate whether the production site’s quality control system can consistently produce compliant products. After the entire process is completed, the manufacturer obtains the certification certificate. It should be noted that IEC 60335 certification typically takes the form of a CB Test Certificate, which serves as a basis for multi‑country access — manufacturers can use a CB report to apply for national certifications in target markets (e.g. CE marking for the EU, RCM for Australia), achieving the efficiency of one test, multiple market access.

Factors That Influence Certification Timeline

Many companies are highly concerned about the duration of IEC 60335 certification. Under typical conditions, a complete IEC 60335 CB test report, with no major issues in samples or documentation, usually falls within a period of 4 to 8 weeks. The actual timeline, however, can vary due to the following factors:

• Sample quality　The closer the samples match the final mass‑production state, the lower the probability of supplementary testing due to design changes. Insufficient sample quantity may also prevent parallel testing, extending the overall schedule.
• Test rounds and depth of rectification　The number and complexity of non‑conformities found in the first round of testing is the biggest variable affecting timeline. Structural problems involving mould modification usually take longer than software parameter adjustments.
• Completeness of documentation　Missing certificates for critical components, circuit diagrams that do not match actual samples, or user manuals lacking necessary safety warnings can all trigger back‑and‑forth verification during the review phase and delay the project closure.
• National difference requirements　As noted earlier, additional testing for national deviation clauses linearly increases the test workload. Manufacturers should clarify the target market list early in the project so that the laboratory can plan the test schedule accordingly.

Frequently Asked Questions on IEC 60335 Certification

Choosing a Testing Partner for IEC 60335

The professionalism of IEC 60335 certification is reflected in the precise interpretation of standard clauses and the scientific design of test plans. A high‑quality certification service goes beyond merely running tests — it is demonstrated through deep technical communication at the start and robust rectification support later. Anci laboratory’s IEC 60335 testing capabilities cover the complete test chain from general requirements to major Part 2 standards, backed by extensive experience gained through successive IEC standard edition transitions.

For home appliance exporters, choosing a service provider that can offer comprehensive technical pre‑assessment at the project initiation stage often brings more long‑term value than simply comparing test fees. Anci’s engineering team for appliance safety certification focuses on engaging from the product design phase, helping manufacturers identify potential non‑compliance risks early and avoiding high‑cost structural rework after mass production begins. This front‑loaded technical collaboration model has been proven in multiple international projects to significantly improve certification efficiency.

Standards tracking and continued compliance remain long‑term topics even after obtaining certification. Although the revision frequency of IEC standards is not high, each edition update may introduce new technical requirements. Anci laboratory’s standard interpretation and technical support can assist manufacturers in continuously monitoring the evolution of the IEC 60335 series, ensuring that certified products smoothly complete edition upgrades within transition periods and maintain market access credentials globally.

This content is AI‑assisted and provided for informational purposes only. It does not constitute any certification commitment or legal advice. Please refer to the latest official regulations for definitive guidance.

Contact: net01@gtggroup.com