Dynamic elaboration on the Art & Science of Hazardous Area Protection
Definition as per IEC 60079-0
Part of electrical equipment or a module, marked with the symbol “U”, which is not intended to
be used alone and requires additional consideration when incorporated into electrical equipment or systems for use in explosive atmospheres
As Ex Components are not intended to be used alone and require additional consideration when incorporated into electrical equipment or systems, they do not have “Specific Conditions of Use” along with the associated “X” suffix for the certificate number.
Where this standard or one of its sub-parts specify “Specific Conditions of Use” and the associated “X” suffix for the certificate number, a “Schedule of Limitations” for the Ex Component certificate and the associated “U” suffix for the Ex Component certificate number shall be substituted for an Ex Component.
The symbol “U” refers to the SUFFIX U which is marked in the Certificate Number of the Ex Component . This component certificate with the “U” SUFFIX clearly shows that the reference component mentioned in the certificate is incomplete and requires further & addition considerations before putting it into an Ex equipment. This fact is elaborated in the “Schedule of Limitation “
Schedule of Limitation :- Additional document included in the certificate , detailing the additional evaluation required before putting the component into operation in a Ex Equipment.
In contrast to the Component Certificate there is The Equipment Certificate.
Equipment certificates are for the complete assemblies