Encapsulation 'Ex m' tests determine if the encapsulation method used to prevent electrical equipment to enclose either sparking or heating parts in a compound, prevent ignition of an explosive gases or vapours or dust.
We can assess and test to the IEC and Australianstandards for explosive atmospheres for equipment protection by encapsulation 'm' for both explosive gas and dust atmospheres.
Properties of compounds are critical for encapsulation type of protection.
As the minimum the following properties shall be considered:
- temperature range of compound (Continuous operating temperature – COT)
- dielectric strength in accordance with IEC 60243-1
- water absorption
- adhesion of compound to component and to enclosureif relevant
- the temperarture index TI value or relative thermal index – RTI-mechanical impact
- Comparative tracking index – CTI
Encapsulation involves specificrequirements for theminimumthickness of the compound surrounding the electrical components and circuit,and its ability to withstand any heat given off by them or the surrounding atmosphere
Electricalandmechanical strength is important and the avoidance of voids within the encapsulant is also important.
Where encapsulated equipment is not able to withstand a single fault (mb) or two faults (ma), a protective device shall be provided either external to the equipment or directly integreated into the equipment.
The protective device shall be capable of interrupting the maximum fault current of the circuit in which is installed. The rated voltage of the protective device must correspond to the working voltage of the circuit in which is installed.
Thermal protective devices shall be used to protect the compound from damage caused by local heating for example due to faulty component.
View our checklist to see if the product complies with the relevant clauses of Encapsulation Ex m - IEC 60079 - 18 before submitting for certification.
Book your test by filling out an application form.