What Do AS/NZS 3820 and IEC 62368-1 Actually Require for Electrical Safety?

Detailed Explanation

AS/NZS 3820 and IEC 62368-1 are cited across this site's compliance and isolation content — the RCM certification process page, the creepage-and-clearance page, and the optocoupler/digital-isolator comparison all reference them as the standard behind a specific requirement — but none of those pages explain what the standards actually require or how the underlying safety model works. This page covers that directly: the essential-requirements-versus-particular-standard relationship, the hazard-based safety engineering model IEC 62368-1 uses, and where electrical safety compliance sits relative to RCM and EMC.

AS/NZS 3820: The Essential Requirements Standard

AS/NZS 3820 (Essential safety requirements for electrical equipment) is Australia and New Zealand's overarching electrical safety standard. It states the safety outcomes electrical equipment must achieve — protection against electric shock, fire, and other hazards arising from the equipment's own electrical energy — without prescribing detailed test methods or numeric limits for every possible product type. In practice, a manufacturer demonstrates compliance with AS/NZS 3820 by showing conformity with a particular standard appropriate to the product category: AS/NZS 62368.1 for audio/video, IT, and communications equipment; AS/NZS 60335 for household appliances; AS/NZS 60950-1 (largely superseded by 62368-1 for new designs) for older IT/telecom equipment; and other category-specific standards for other equipment types. Identifying the correct particular standard for a given product category is the first practical step in an electrical safety compliance plan.

IEC 62368-1 and Hazard-Based Safety Engineering (HBSE)

For most modern consumer electronics, AV, IT, and communications products, the applicable particular standard is AS/NZS 62368.1, Australia and New Zealand's national adoption of the international IEC 62368-1 standard. IEC 62368-1 replaced the older IEC 60950-1 (IT equipment) and IEC 60065 (audio/video equipment) standards with a single, hazard-based approach that applies across both former product categories.

Rather than a prescriptive checklist of construction rules, IEC 62368-1 is built around a three-block causal model:

1. Energy source — anything inside the product capable of causing harm: mains voltage, a charged capacitor, a hot surface, a spinning fan blade, a laser diode, a chemical hazard.
2. Transfer mechanism — the path by which that energy could reach a person or another part of the equipment (exposed conductive parts, an accessible enclosure opening, a failure that removes a barrier).
3. Body — the person (or, for internal safety, another component) that would be harmed if the energy reached them without a safeguard in place.

Every energy source in the design is classified by class (roughly: unlikely to cause harm, may cause harm but not serious injury, or can cause serious injury) for each hazard type it represents — electrical, thermal/burn, mechanical, radiation, chemical, or acoustic. The standard then requires one or more safeguards — a basic safeguard, or a combination of independent safeguards (a basic safeguard plus a supplementary safeguard, or a single reinforced safeguard providing equivalent protection to both) — positioned between the energy source and the body, sized to the energy source's classified severity. Reinforced or double insulation between mains voltage and a user-accessible surface is a familiar real-world example of this pattern; the reinforced isolation ratings discussed for optocouplers and digital isolators are the same safeguard concept applied to a signal-isolation barrier rather than a product enclosure.

Where This Fits Relative to RCM and EMC

Electrical safety compliance under AS/NZS 3820 / AS/NZS 62368.1 is a distinct regulatory requirement from the EMC and radiocommunications domains covered in how to get RCM certification in Australia — all three must be satisfied independently, and passing one says nothing about the others. In addition to the RCM framework administered by the ACMA (which bundles EMC, radio spectrum, and, for in-scope equipment, electrical safety declarations together for the products it regulates), some electrical product categories are additionally regulated under the state- and territory-administered Electrical Equipment Safety System (EESS), coordinated nationally through the Electrical Regulatory Authorities Council (ERAC). EESS applies a risk-based registration and certification scheme to specific "in-scope" electrical equipment categories, with higher-risk equipment requiring more rigorous third-party certification than a simple supplier's declaration of conformity. Which regime (or combination) applies depends on the specific product category — confirm against the current ERAC/EESS in-scope equipment list rather than assuming RCM alone covers electrical safety for every product type.

Design Considerations

• Identify the product's particular standard early, not at the compliance-testing stage. AS/NZS 3820 itself won't tell you what to design against; you need to know whether AS/NZS 62368.1, AS/NZS 60335, or another category-specific standard applies before insulation, spacing, and protective-earthing decisions are locked in — retrofitting a safety-critical construction change late in a design is expensive.
• Extra-low-voltage products still have some obligations. Below the extra-low-voltage threshold (commonly cited as 50 V AC / 120 V DC ripple-free), electrical-shock energy sources are typically much less of a concern, but thermal, mechanical, and (for lithium-battery products) chemical energy sources under the same hazard-based model can still apply — a low-voltage product is not automatically exempt from every clause.
• A safeguard's rating must match the energy source's classified severity, not an arbitrary margin. The creepage and clearance distances required at a PCB level, and the isolation voltage rating required of an optocoupler or digital isolator, are both direct outputs of this classification process — the correct spacing or isolation rating depends on the actual working voltage, pollution degree, and material group involved, not a generic "high voltage = big gap" rule of thumb.
• A certified sub-assembly narrows scope; it doesn't certify the product. A pre-certified power supply, connector, or isolation component satisfies its own portion of the safety case, but the complete product — its enclosure, wiring, battery, and integration of that sub-assembly — still needs its own assessment.

Common Mistakes

• Treating "RCM compliant" and "electrically safe" as automatically synonymous. RCM bundles multiple compliance domains together for the product categories ACMA regulates, but electrical safety is assessed against its own standard and can fail independently of EMC or radio compliance.
• Assuming AS/NZS 3820 alone specifies a test method. AS/NZS 3820 states the required safety outcome; the actual construction rules, spacing tables, and test procedures come from the particular standard (most commonly AS/NZS 62368.1) — designing against AS/NZS 3820's essential requirements alone, without consulting the particular standard, leaves the detailed compliance work undone.
• Overlooking product-category-specific standards that sit outside IEC 62368-1's scope. Household appliances, medical devices, and industrial equipment are typically governed by their own particular standards (AS/NZS 60335, IEC 60601, IEC 61010, respectively) rather than AS/NZS 62368.1 — confirm the correct standard family for the actual product category rather than defaulting to the AV/IT/communications standard because it's the most commonly discussed.
• Ignoring the separate battery safety standard on a lithium-battery product. A product's overall electrical safety compliance under AS/NZS 62368.1 does not by itself cover the lithium cell's own safety requirements — those are addressed separately (commonly under IEC 62133), and both need to be satisfied for a battery-powered product.

For product designs that need to navigate electrical safety, EMC, and RCM compliance together, Zeus Design's engineering team supports compliance-aware design from schematic through certification.