Заранее огромное спасибо

да
там в тексте написано черными буквами: These panels are too large to be Exd

У меня словаря с такой тематикой нет
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Methods of Protection
Purging and
Pressurising (Exp)
EN IEC 60079-2 (EN IEC 60079-0 also applies)
This protection method is often used for large
electric motors, or large control cabinets
containing switchgear, circuit boards etc.
The principle of the protection method is to first
pressurise the enclosure with air or inert gas, then
to purge any hazardous gas that may be present
inside the enclosure by passing a large volume of
air or inert gas through the enclosure. Finally,
when purging is complete, an overpressure is
maintained to prevent hazardous gas from re-
entering the enclosure. The equipment can then
be energised.
Provided the equipment has an enclosure that will
keep pressurising air leakage low, most industrial
equipment is suitable with minimal modifications.
This has the advantage that changes to adapt an
existing product to achieve compliance can be
minimised.