Differences Between Ex ec and Ex nA Protection: Technology, Standards, and Selection Guide

Ex ec and Ex nA: Technical Relationship and Background of the Standard Renaming

The new edition of the IEC/EN 60079-7 standard, published in 2015, officially renamed Ex nA to Ex ec. This change is not a technical upgrade but the result of integrating the standards system. Technically, the two types of protection are completely identical, and Ex ec is explicitly defined as the successor to Ex nA.

Standard Transition and Timeline

How Long the Ex nA Designation Will Remain

The old standard IEC/EN 60079-15:2010 has not yet been withdrawn, so both Ex nA and Ex ec markings are currently circulating in the market. However, according to industry expectations, Ex nA will be removed from the standard within the next two years.

When New Equipment Must Be Marked Ex ec

Once IEC/EN 60079-15:2010 formally expires, all newly introduced equipment must be marked Ex ec. This mandatory date is expected to arrive in about four years.

Field Device Marking Update Plan

The transition from Ex nA to Ex ec has already begun. Over the next few years, all related equipment will gradually complete updates to labels, documentation, and certificates. Users should pay attention to specific change notices issued by manufacturers.

Can Ex ec and Ex nA Devices Be Operated Together?

Yes. Ex ec was introduced as the explicit successor to Ex nA, and the two have been confirmed to be technically identical. Therefore, mixing Ex nA and Ex ec devices in the same system is permitted without additional technical measures.

Core Comparison and Key Information

Affected Products and Source

This information applies to the PD, PA, PI series field devices. Relevant technical documentation can be found in Siemens official materials (info, 62.2 KB).

To learn about the certificate update status of specific devices, please consult the manufacturer's latest announcements.