Evolving protection concepts for motors – Non-sparking becomes part of increased safety
If you use motors for explosive atmospheres, you may have heard about standard changes covering the non-sparking and increased safety protection concepts.
A revised edition (5.0) of IEC 60079-7, which covers the increased safety protection concept, was published in mid-2015 and approved as a European EN standard later the same year. The main change is that the technical requirements for increased safety have expanded to include those for the non-sparking concept.
In practice the technical requirements for LV motors have not changed, but there are now two levels of increased safety protection and this will affect the way motors are marked.
The effects of the revision are gradually becoming visible in the marketplace as manufacturers update their type certificates and the new markings start to appear on motors.
In Europe there is an official deadline for compliance, as EU Declarations of Conformity documents (ATEX) must refer to the new revision of the standard by August 2018 at the latest. At ABB we have initiated a project to update the type certificates for our non-sparking and increased safety motors during 2017, and we will start to put the new markings on motors when the certificates are updated. In fact, we have already launched our first products with the new increased safety Ex ec marking: aluminum frame motors in sizes 160 to 280 were introduced in April.
How do the revised standards impact motor users? The main thing is to be aware of the changes and take care not to confuse the protection levels. For increased safety applications in Zone 1 you need an Ex eb (or older Ex e) motor. Motors marked with Ex ec (and older non-sparking Ex nA) motors can only be used in Zone 2.
Have you started updating your specifications to reflect these changes?