IEC 60079-0:2011 pdf – Explosive atmospheres – Part 0: Equipment – General requirements.
distance through casting compound
shortest distance through a casting compound between two conductive parts
distance through solid insulation
shortest distance through solid insulation between two conductive paris
distanc, under coating
shortest distance between conductive parts along the surface of an insulating medium covered with insulating coating
symbol “U’
symbol used to denote an Es Component
NOTE The symbol Is used to identity that the equipment is incomplete and is not suitable fo Installation witho4A further evaluation
symbol used to denote specific conditions of use
NOTE The symbol x is used to provide a means of identifying Itat essential information fat the installation, use, and malntennnce of th. equipment is contarncd within h. c.rtiticat..
termination compartment
separate compartment, or part of a main enclosure, communicating or not with the main enclosure. end containing connection facilities
test, routine
test to which each Individual device Is subjected during or after manufacture to ascertain whether It complies with certain criteria
test, type
test of one or more devices made to a certain design to show that the design meets certain specifications
type of protection
specific measures applied to electrical equipment to avoid ignition of a surrounding explosive atmosphere
unintentional space created as a consequence of the encapsulation process
working voltage
highest value of the ac. or d.c. voltage across any particular insulation which can occur when the equipment is supplied at rated voltage
NOTE I Transients at. disregard.d
NOTE 2 Both open-circuit conditions and normat operating conditions are taken Into account
maximum surface temperature for Group I electrical equipment, if there is no risk of ignition from these surfaces, with a safety margin of
• 5OKforTl,T2andT3,
• 25 K for T4, T5 and T6 and Group I.
This safety margin shall be ensured by experience of similar components or by tests of the
electrical equipment Itselt In representative explosive mixtures.
NOTE During the teats, the safety margin may be provided by increasing tie ambient tempereture or by the power dissipation of the component. For methane, the second option is recommended
6 Requirements for all electrical equipment
6.1 General
Electrical equipment and Ex Components shall
a) comply with the requirements of this standard, together with one or more of the specific standards listed in Clause 1. and
NOTE These specific slandeidni nay very the iequiremente of thés stendeid.
NOTE 2 All of the requirements for cable glenda marked cc typ. of protection s ate located in IEC 50079.0
b) be constructed in accordance with the applicable safely requirements of the relevant industrial standards.
NOTE 3 Ills not a requirelnenl of this standard th.t compliance wilt’ PieS ind,4triel standards be vefl*ied
NOTE 4 It (tiS electrical equipment on En Component is intended to withstand particularly adverse serrirn condibons (for saarnpi. rough handling, humidity effects, ambient tetnperalure variations, effects of chemical agents, corrosion), thesa should be specified to me manutacturer by the usec, It certification is sought. it is not a requwensenl of this slanderd thaI the cert.fbcet,on body contirni suitability for tine adverse conditions, Sp.ciel precaullorms should be taken witien vitwallon effects on lermitnals. tuse holders. tamphdders and currevlt’c.rrywng connection, in general nay impair safely, unless they comply with specific standerds.
6.2 Mechanical strength of equipment
The equipment shall be subjected to the tests of 26.4. Guards relied upon to provide protection from impact shall be removable only by the use of a tool and shall remain in place for the required impact tests.
6.3 OpenIng times
Enclosures which can be opened more quickly than
a) any incorporated capacitors, charged by a voltage of 200 V or more, to discharge to a value of residual energy of
— 0.2 mJ for electrical equipment of Group I or Group lIA,
— 0.06 mJ for electrical equipment of Group llB,
— 0.02 mJ (or electrical equipment of Group IC, including equipment marked Group II only,
— 0.2 mJ for electrical equipment of Group Ill,
or double the above energy levels lithe charging voltage is less than 200 V. or
b) the surface temperature of enclosed hot components reduces to below the assigned maximum surface temperature of the electrical equipment
shall be marked with one of the following warning markings.