This style of protection involves making an enclosure tight enough so that combustible dust cannot enter. Consequently, protection "by enclosure" is targeted specifically at explosive dust atmospheres, and is not suited to explosive gas atmospheres.

Protection by enclosure 't' has the advantage of being easy to understand, and - in many cases - being fairly straightforward to accomplish. It is also a mechanical design technique, rather than an electrical one, which makes it attractive to electrical designers. It is also often the case that the equipment enclosure has to be dust-tight for practical reasons, meaning the equipment may "automatically" conform to type 't'.

It is important, however, not to underestimate the requirements. Many "dust-tight" enclosures will not naturally meet the requirements for protection by enclosure, and not all enclosures can easily be made dust-tight. In some cases choosing this protection method will simply move the effort from the electrical side to the mechanical side, which may or may not be advantageous. In some cases the design effort and risk may actually increase by selecting this technique.

Go to Protection Techniques.
Go to Certification Standards.
Go to Understanding ATEX.
Go to Understanding IEC 60079.