Intrinsic safety simple apparatus: the standards boundary
The official IEC page for IEC 60079-11:2023 identifies Edition 7.0 for equipment protection by intrinsic safety i. It covers construction and testing of intrinsically safe apparatus and associated apparatus connected to intrinsically safe circuits that enter explosive atmospheres. The page is marked Corrected Version 2026-07 and says that the copy incorporates the listed corrigenda and interpretation sheets through July 2026.
That current status matters because an old extract, training slide or inherited drawing may not reflect the controlled edition required by the project. The public abstract confirms the broad equipment boundary, but it does not reproduce all requirements for classifying simple apparatus. Buyers should use the licensed standard and controlled project basis rather than importing thresholds or examples from an unverified web page.
The official IEC page for IEC 60079-25:2020 identifies Part 25 as the standard for design, construction and assessment of intrinsically safe electrical systems. Its consolidated version is labelled IEC 60079-25:2020+AMD1:2025 CSV. It supplements and modifies IEC 60079-0 and IEC 60079-11, and points Group II and Group III installation requirements to IEC 60079-14.
Why a component name cannot approve an Ex i loop
Intrinsic safety protects through control of circuit energy under the applicable conditions. The relevant decision therefore concerns the circuit and system, not only the physical size or apparent simplicity of one item. A switch, sensor, junction point or other component must not be called simple apparatus from its photograph, catalogue category or informal supplier statement.
The MMAIATEX guide to intrinsic safety entity parameter matching explains one first-screen relationship between associated apparatus, field apparatus and cable. Passing a parameter comparison still does not approve the complete system. The system assessment must address the actual topology, connected equipment, cable contributions, group, protection level, temperature, ambient range, faults, installation conditions and document restrictions.
Simple apparatus is part of that system evidence. It is not a way to avoid the system assessment or to transfer responsibility to the purchaser. Whether a separate product certificate is required depends on the applicable conformity route and exact classification. The buyer should not replace that decision with a general statement that simple apparatus is exempt.
Eight buyer checks before acceptance
1. Define the intended function
State what the item does in the circuit, where it is located, which terminals and conductors are involved, and what normal and abnormal conditions must be considered. Record whether it stores, generates, dissipates, switches or transfers energy. Do not infer function from enclosure shape or terminal count.
2. Request the classification rationale
Ask the responsible manufacturer or system designer to identify the current IEC 60079-11 basis and explain why the exact item qualifies. The file should identify model or drawing, construction, materials, electrical characteristics, temperature considerations and any supporting data or tests. A purchase description that says only simple apparatus is not a technical justification.
3. Freeze the complete system topology
Identify every source, associated apparatus, field apparatus, simple apparatus item, cable and connection. Record which circuits enter the explosive atmosphere and which equipment is outside it or protected by another protection type. A change from one source to multiple sources, or from one field item to several branches, can change the required assessment method.
4. Complete the IEC 60079-25 assessment
Apply the current system standard to the real topology. Include apparatus data, cable contributions, stored energy, generated energy, fault conditions, temperature effects and every certificate or control drawing condition that belongs to connected equipment. Do not use a successful spreadsheet comparison as approval when the arrangement requires a fuller method.
5. Match group, EPL and environmental limits
Confirm the approved hazardous-area classification, required equipment group and EPL, gas or dust context, temperature information and ambient range. The MMAIATEX Equipment Protection Levels guide explains why a Zone and an EPL are related but not interchangeable. A simple apparatus classification does not correct a mismatch in atmosphere, temperature or protection level.
6. Design the installation before purchase
IEC 60079-14:2024 covers electrical installation design, selection, installation and required initial inspection, including documentation and personnel competency. Use the MMAIATEX IEC 60079-14 buyer checklist to bring cable, terminals, segregation, identification, earthing, mounting, environmental protection and inspection inputs into the order. The guide does not replace the licensed standard or site design.
7. Build a controlled dossier
Keep the area classification, system descriptive document, circuit drawing, apparatus schedules, certificates where applicable, simple apparatus rationale, calculations, cable data, instructions, special conditions, installation records and initial inspection result together. Match revisions and model suffixes. A certificate for one connected item is not a certificate for the complete loop.
The guide on verifying IECEx certificates and ATEX documents provides an identity and status workflow for documents that are part of the evidence set. The IECEx standards page confirms that Parts 11, 14 and 25 are among standards used by the IECEx System, but a standards list is not a certificate for a product or system.
8. Assign competent review and change control
Name the competent people responsible for design, assessment, installation and initial inspection. Require review before substituting a barrier, component, cable, terminal, enclosure, supply or earthing arrangement. Record the reason, technical basis, approval and revised documents. Do not energise an altered loop because the replacement appears electrically similar.
Red flags in supplier or project files
Pause the review when the simple apparatus claim has no drawing or rationale, the system topology is incomplete, cable data are missing, revisions conflict, temperatures are not addressed, or certificates belong to different models. Also stop when a supplier treats a passive appearance as proof, calls the item automatically safe, or says that no competent assessment is needed.
The corrected 2026 status of IEC 60079-11 is another document control check. It does not automatically invalidate every earlier project decision, and it does not create a certificate. The responsible project parties must determine the edition and transition basis required by contract, law, certification scheme and authority having jurisdiction.
Current MMAIATEX certification status
MMAIATEX is the public brand of MMAIATEX Explosion-proof Technology (Zhejiang) Co., Ltd. The public About page states that ATEX, IECEx and CCC certification work is in progress. This article, a simple apparatus description, a circuit diagram, an IEC standard reference, a photograph or a product category does not prove that a particular MMAIATEX model or intrinsically safe system is certified. Verify exact-model marking, current documents, scope, conditions, associated equipment and installation basis.
Safety and legal disclaimer
This article is general technical information, not a simple apparatus classification, circuit calculation, system descriptive document, certificate, hazardous-area classification, installation design, initial inspection, legal opinion or permission to energise equipment. Obtain the licensed current standards and use competent professionals with exact site and product data. An incorrectly assessed circuit can create an ignition risk. Isolate equipment and stop work when identity, parameters, documentation or system conditions are uncertain.
Contact MMAIATEX for an evidence request
Send the exact model, circuit function, system drawing, associated apparatus, cable data, area classification and required destination documents so MMAIATEX can organise available product information for competent project review.