I E C TS 60 0 7 9 -46

®
Edition 1 .0 201 7-08

TE C H N I C AL

S P E C I F I C ATI ON

E xpl os i ve atm os ph e res –

P art 46: E q u i pm e n t as s e m bl i es
IEC TS 60079-46:201 7-08(en)
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 I E C TS 60 0 7 9 -46
®
Edition 1 .0 201 7-08

TE C H N I C AL

S P E C I F I C ATI ON

E xpl os i ve atm os ph ere s –

P art 46: E q u i pm en t as s em bl i es

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION

ICS 29.260.20 ISBN 978-2-8322-4763-1

Warn i n g ! M ake s u re th a t you ob tai n ed th i s p u b l i cati on from an au th ori zed d i s tri b u tor.

® Registered trademark of the International Electrotechnical Commission

 –2– I EC TS 60079-46: 201 7 © I EC 201 7

CON TEN TS
FOREWORD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
I N TRODU CTI ON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2 N orm ati ve references . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3 Term s and d efi n i ti ons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4 General requ irem en ts for eq ui pm en t assem bl ies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4. 1 General specificati ons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4. 2 Expl osi on protection specificati ons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4. 3 H azardous area cl assificati on rel ated to th e eq u ipm ent assem bl y . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4. 3. 1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4. 3. 2 Equ i pm ent assem bl y with i ts own source of release . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4. 4 Com petencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5 Design of eq ui pm en t assem bl ies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5. 1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5. 2 Ex Eq u ipm en t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5. 2. 1 I n d ivid u al item s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5. 2. 2 Specific Con di tions of U se as specifi ed on certificates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 0
5. 2. 3 I tem l ist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 0
5. 3 Oth er i tem s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 0
5. 4 Wiring system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 0
5. 5 Drawin
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.... ................. 1 1
6 Constru ction and assem bl y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1
6. 1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1
6. 2 Disassem bl y an d reassem bl y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1
6. 3 System interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2
6. 4 I g n iti on hazard assessm en t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2
6. 5 Calcu lations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2
6. 6 I nspecti on & testin g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2
6. 7 Val i d ation an d d ocum entati on . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 3
6. 7. 1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 3
6. 7. 2 Oth er m ateri al specificati ons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4
6. 7. 3 Sched u le Docu m ents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4
6. 8 I nstructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4
7 Certificate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4
8 M arkin g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 5
8. 1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 5
8. 2 Determ i n in g Grou p m arki ng . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 5
8. 3 Determ i n in g tem perature cl ass or m axim um surface tem perature m arking . . . . . . . . . . . . 1 6
8. 4 Determ i n in g Eq u ipm en t Protecti on Level (EPL) m arkin g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 6
8. 5 Determ i n in g am bient tem perature ran ge m arkin g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 6
8. 6 Determ i n in g i n gress protecti on (I P Code) rati ng . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 6
I EC TS 60079-46: 201 7 © I EC 201 7 –3–

I N TERN ATI ON AL ELECTROTECH N I CAL COM MI SSI ON

____________

EXPLOSIVE ATMOSPHERES –
Part 46: Equipment assemblies
FOREWORD
1 ) Th e I n ternati on al El ectrotechn i cal Com m i ssi on (I EC) i s a worl d wi d e organ i zati on for stan d ard i zati on com pri si n g
al l n ati on al el ectrotech ni cal com m i ttees (I EC N ati onal Comm i ttees). The obj ect of I EC i s to prom ote
i n ternati on al co-operati on on al l q u esti on s concern i n g stand ard i zati on i n th e el ectri cal an d el ectroni c fi el d s. To
thi s end and i n ad d i ti on to other acti vi ti es, I EC pu bl i sh es I n ternati on al Stan d ard s, Tech n i cal Speci fi cati on s,
Tech ni cal Reports, Pu bl i cl y Avai l abl e Speci fi cati ons (PAS) an d Gu i d es (h ereafter referred to as “I EC
Pu bl i cati on (s)”). Thei r preparati on i s entru sted to techn i cal com m i ttees; any I EC N ati on al Com m i ttee i n terested
i n th e su bj ect d eal t wi th m ay parti ci pate i n th i s preparatory work. I nternati on al , g overn m ental an d n on -
g overn m en tal organ i zati ons l i ai si ng wi th th e I EC al so parti ci pate i n th i s preparati on. I E C col l aborates cl osel y
wi th the I ntern ati on al Org ani zati on for Stand ard i zati on (I S O) i n accord ance wi th con d i ti ons d eterm i ned by
agreem en t between th e two org an i zati on s.
2) Th e form al d eci si ons or ag reem en ts of I EC on tech n i cal m atters express, as n earl y as possi bl e, an i ntern ati onal
consen su s of opi ni on on th e rel evant su bj ects si n ce each tech ni cal com m i ttee h as represen tati on from al l
i n terested I EC N ati on al Com m ittees.
3) I EC Pu bl i cati on s have th e form of recom m end ati on s for i n tern ati onal u se an d are accepted by I EC N ati on al
Com m i ttees i n that sen se. Whi l e al l reasonabl e efforts are m ad e to ensu re th at th e tech n i cal conten t of I EC
Pu bl i cati on s i s accu rate, I EC can n ot be h el d respon si bl e for th e way i n whi ch th ey are u sed or for an y
m i si nterpretati on by an y en d u ser.
4) I n ord er to prom ote i n tern ati on al u ni form i ty, I EC N ati onal Com m i ttees u n d ertake to appl y I EC Pu bl i cati ons
transparentl y to the m axi m u m extent possi bl e i n thei r n ati onal an d reg i on al pu bl i cati on s. Any d i verg en ce
between an y I EC Pu bl i cati on an d the correspond i n g nati on al or reg i on al pu bl i cati on sh al l be cl earl y i n d i cated i n
the l atter.
5) I EC i tsel f d oes n ot provi d e an y attestati on of con form i ty. I n d epen d en t certi fi cati on bod i es provi d e con form i ty
assessm ent servi ces an d , i n som e areas, access to I EC m arks of conform i ty. I EC i s not respon si bl e for an y
servi ces carri ed ou t by i n d epen d en t certi fi cati on bod i es.
6) Al l u sers sh ou l d en su re th at th ey h ave the l atest ed i ti on of th i s pu bl i cati on.
7) N o l i abi l i ty shal l attach to I EC or i ts d i rectors, em pl oyees, servants or ag en ts i ncl u d i n g i n d i vi d u al experts an d
m em bers of i ts tech n i cal com m i ttees and I EC N ati on al Com m i ttees for any person al i n j u ry, property d am ag e or
other d am ag e of any n atu re wh atsoever, wheth er d i rect or i n d i rect, or for costs (i n cl u d i n g l eg al fees) and
expenses ari si ng ou t of th e pu bl i cati on, u se of, or rel i an ce u pon, th i s I EC Pu bl i cati on or an y oth er I EC
Pu bl i cati ons.
8) Atten ti on i s d rawn to th e N orm ati ve references ci ted i n th i s pu bl i cati on. U se of the referen ced pu bl i cati ons i s
i n d i spensabl e for th e correct appl i cati on of th i s pu bl i cati on .
9) Atten ti on i s d rawn to th e possi bi l i ty th at som e of th e el em en ts of th i s I EC Pu bl i cati on m ay be th e su bj ect of
paten t ri g hts. I EC sh al l n ot be h el d responsi bl e for i d enti fyi ng an y or al l su ch paten t ri gh ts.

The m ain task of I EC techn ical com m ittees is to prepare I ntern ati onal Stan dards. I n
excepti onal circum stances, a tech n ical com m ittee m ay propose th e publ i cati on of a tech n ical
specification wh en

• th e requ ired su pport can not be obtain ed for th e pu bl ication of an I n tern ati onal Stan d ard ,
d espite repeated efforts, or
• th e subj ect is stil l u nd er tech n ical d evelopm en t or wh ere, for an y oth er reason , th ere is th e
fu ture but no im m ed iate possibili ty of an agreem ent on an I ntern ati on al Stand ard.
Techn ical specificati ons are subj ect to review wi thi n th ree years of publ icati on to decid e
wh eth er th ey can be tran sform ed in to I n tern ational Stan d ards.

I EC TS 60079-46, wh ich is a tech n ical specificati on , has been prepared by I EC tech n ical
com m ittee TC 31 : Eq u ipm ent for expl osi ve atm osph eres.
 –4– I EC TS 60079-46: 201 7 © I EC 201 7

The text of th is tech n ical specification is based on th e fol l owi n g docum en ts:

Enq u i ry d raft Report on voti n g

31 /1 31 2/DTS 31 /1 327/RVDTS

Fu l l i nform ation on th e voti ng for the approval of this techn ical specificati on can be fou n d in
th e report on voti n g i nd icated i n th e above tabl e.

This d ocum en t h as been drafted in accord ance wi th th e I SO/I EC Directi ves, Part 2.

A list of al l parts in th e I EC 60079 seri es, pu blish ed u nd er th e g eneral titl e Explosive

atmospheres , can be fou nd on th e I EC websi te.
The com m ittee h as deci ded that the con ten ts of th is pu blication wil l rem ai n unch ang ed u nti l
th e stabi l ity d ate in d icated on the I EC website un d er "h ttp: //webstore. i ec. ch " i n th e d ata
related to th e specific pu blication. At th is d ate, th e publ icati on wil l be
• transform ed in to an I n ternation al stan dard ,
• reconfi rm ed,
• wi thd rawn ,
• repl aced by a revised ed iti on, or
• am end ed.
A bi l in g ual versi on of th is pu bl icati on m ay be issu ed at a l ater d ate.

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I EC TS 60079-46: 201 7 © I EC 201 7 –5–

I N TRODUCTI ON

The provisi on of prod ucts into en d m arkets for i n stal l ation by end users m ay take the form of
either in di vi d ual item s of eq u ipm ent or pre-m an u factured assem bl ies com prisin g m an y i tem s
of equ i pm en t. Pre-m an ufactured eq u ipm en t assem bl i es m ay be as eith er subsystem s
req u iring i ntegration as part of an instal lation at a site or com pl ete fu ncti on al m ach in es wh ich
req u ire l ittle or n o ad d itional reassem bl y on site.

This d ocum ent is appl i ed wh en assem bl y of Ex Eq u ipm ent(s) resu l ts i n an assem bl y th at

creates a n eed for ad d itional assessm en t that is n ot alread y com pletel y covered by the
ind i vi du al eq u ipm ent certificates. Ad di tion al assessm ent m ig ht incl ud e (but is n ot l im ited to)
eval u ation of wiri n g m eth ods used to con nect th e eq u i pm ent(s) or tem perature rise wi thi n th e
assem bl y.

This d ocum en t provid es req ui rem en ts for th e d esig n , constructi on , assem bl y, testi n g,
inspection, m arking , d ocum enti n g an d assessm ent of equ i pm en t assem bl ies such th at the
item s of Ex Eq u i pm ent and th e in tercon nection of the item s of equ ipm ent form an assem bl y
th at also m eets oth er parts of the I SO 80079 an d I EC 60079 series.

This docum en t is intend ed to be used for verification of assem bl ies to assist in ensu rin g
prod ucts are in com pl ian ce wi th th e req u irem ents of th e I SO 80079 and I EC 60079 seri es at
th e tim e of i n iti al i nstall ati on at the en d user si te.

After th e in i tial instal lati on , th e assem bl y is consid ered as part of th e site i nstal lation in
accord ance wi th other parts of th e I SO 80079 an d I EC 60079 seri es.
 –6– I EC TS 60079-46: 201 7 © I EC 201 7

EXPLOSIVE ATMOSPHERES –
Part 46: Equipment assemblies

1 Scope
This part of I EC 60079, wh ich is a tech n ical specification, specifi es requ irem en ts for th e
desi g n, construction, assem bl y, testi n g, i nspecti on, m arking , d ocu m en tin g and assessm en t of
eq u i pm ent assem bl ies for u se i n expl osi ve atm ospheres u nd er th e responsibi l ity of the
m anufacturer of th e eq ui pm ent assem bl y.

The requ irem en ts of th i s d ocum ent appl y to in d i vi d u al item s accord i n g to th e I EC 60079

series or I SO 80079 series th at com prise th e assem bl y and th at h ave in d i vi du al certificates.
These in d i vid u al item s are th en i ntegrated as part of the eq u ipm ent assem bl y. Also inclu d ed
are requ irem en ts to ad dress aspects for th e assem bl y wh ich m ay be beyond th e certificates of
th e in di vi d ual item s form ing th e assem bl y.

The scope of th is d ocum ent incl ud es assessm ent of th e add ition al requ irem ents for
assem bl ies for hazard ou s areas an d d oes not i ncl ud e req u irem en ts for n on -h azardous areas.
I t is assum ed that com pli ance with other el ectrical or m ech an ical req u irem en ts th at are
appl icabl e for n on-h azard ous areas wi l l be verifi ed by eith er the sam e or d ifferen t party i n
ad d iti on to th e req u irem ents of th is docum ent.

This d ocum en t d oes not appl y to:

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– eq u i pm ent wh ich is covered , in its en tirety, by on e or m ore I EC 60079 an d I SO 80079
eq u ipm ent types of protection;
– pressuri zed room s, “p”, in accordance wi th I EC 60079-1 3, artificial venti l ati on for the
protecti on of an al yzer(s) h ouses i n accordance wi th I EC TR 60079-1 6, an d oth er
stan d ards ad dressi n g specific Ex assem bl i es;
– install ation at th e end-u ser site u n der th e scope of I EC 60079-1 4;
– cl assification of th e h azardous area;
– eq u i pm ent assem bl i es for m in es suscepti bl e to fired am p (Grou p I appl icati ons);
– i nh eren tl y expl osive si tu ations an d dust from explosi ves or pyrophoric substances (for
exam ple expl osi ves m an u factu ri ng an d processi n g);
– room s used for m ed ical purposes;
– electrical instal l ati ons in areas wh ere th e hazard i s d u e to fl am m abl e m ist.
The specification is on l y i ntend ed to provi de val i d ati on for th e i n itial suppl y of an assem bl y.

N OTE 1 Ad d i ti on al g u i d an ce on th e req u i rem ents for h azard s d u e to h ybri d m i xtu res of d u st or fl yi n gs an d

fl am m abl e gas or vapou r i s provi d ed i n I EC 60079-1 4.

Where a req u irem ent of th is d ocum ent confl icts with a requ irem en t of ei ther I EC 60079-0 or
I SO 80079-36, th e requ irem ent of this docum en t takes precedence.

N OTE 2 For thi s fi rst ed i ti on , the onl y req u i rem ents of thi s d ocu m ent th at take preced en ce over I EC 60079-0 or
I SO 80079-36 are th e m arki ng s for eq u i pm ent assem bl i es.
I EC TS 60079-46: 201 7 © I EC 201 7 –7–

2 Normati ve references

The fol l owi n g d ocum ents are referred to i n th e text in such a way that som e or al l of their
con ten t constitutes requ irem ents of th is d ocum ent. For d ated references, on l y th e ed ition
cited appl i es. For u nd ated references, th e l atest ed ition of the referenced d ocum en t (incl ud in g
an y am endm en ts) appl i es.

I EC 60079 (al l parts), Explosive atmospheres

I EC 60079-0, Explosive atmospheres – Part 0: Equipment – General requirements
I EC 60079-1 0-1 , Explosive atmospheres – Part 10-1: Classification of areas – Explosive gas
atmospheres
I EC 60079-1 0-2, Explosive atmospheres – Part 10-2: Classification of areas – Explosive dust
atmospheres
I EC 60079-1 4, Explosive atmospheres – Part 14: Electrical installations design, selection and
erection
I EC 60079-25, Explosive atmospheres – Part 25: Intrinsically safe electrical systems
I SO 80079 (all parts), Explosive atmospheres
I SO/I EC 80079-34, Explosive atmospheres – Part 34: Application of quality systems for
equipment manufacture
I SO 80079-36,Explosive atmospheres – Part 36: Non-electrical equipment for explosive
atmospheres – Basic method and requirements

3 Terms and definitions

For th e pu rposes of th is d ocum ent, th e term s and defin i tions g i ven i n I EC 60079-0,
I EC 60079-1 4, I SO 80079-36 an d th e foll owi n g appl y.

I SO an d I EC m ai n tain term in olog ical databases for use in stan d ardi zati on at th e fol l owing
ad dresses:

• I EC El ectroped i a: avai labl e at h ttp: //www. el ectroped ia. org /

• I SO On l in e browsi n g platform : avai l abl e at http: //www. iso. org/obp
3. 1
equ ipment assembly
pre-m anufactured com bination of Ex Equ ipm ent, tog ether wi th other parts as n ecessary, th at
are electrical l y or m ech an ical l y interconn ected th at are pre-assem bl ed pri or to bei n g placed
into service at the en d-u ser site, an d th at can be d isassem bl ed an d th en re-assem bl ed at th e
en d-user site

3.2
equ ipment assembly certifi cate
docum en t that con veys th e assurance of th e conform ity of an eq u i pm ent assem bl y wi th
specified req uirem en ts

N ote 1 to entry: The certi fi cate i s ei ther the su ppl i er’ s d ecl arati on of conform i ty or the pu rchaser’ s recog n i ti on of
con form i ty or certi fi cati on (as a resu l t of acti on by a thi rd party) as d efi n ed i n I SO/I EC 1 7000: 2004, d efi n i ti on 2.
 –8– I EC TS 60079-46: 201 7 © I EC 201 7

3.3
pre-manufactu red
eq u ipm ent assem bl y produ ced at an y l ocati on(s) oth er th an th e en d-user site

4 General requirements for equipment assemblies

4.1 General specification s
The equ ipm ent assem bl y sh al l be verifi ed for su itabi l ity ag ai nst th e req u irem ents of th is
docu m en t, I EC 60079-0, I EC 60079-1 4 an d I SO 80079-36 as appl icable.

The gen eral specificati ons m ay be provided by the en d-user or by th e m an ufacturer for th e
inten d ed use of the eq u ipm ent assem bl y and sh al l cover th e fol l owi n g as a m inim u m :
– m anu factu rer’s u n iq u e eq u ipm en t assem bl y i d en tifi er (e. g . serial n um ber);
– i npu t an d output ratin gs;
– i nten d ed en vi ronm en tal con d iti ons, incl u din g am bient tem perature ran ge and i ngress
protecti on ;
– appl icabl e expl osi on protecti on cod es, stand ards an d reg u lations;
– uti l ity-rel ated issu es, i ncl ud i n g power su ppl y;
– an y req u irem ents for item s to be u sed i n th e eq u i pm ent assem bl y;
– process con d itions, i nclu d in g flu i ds, pressu res, d u ty;
– external sources of heati ng an d coolin g;
– external i n terface param eters (e. g . for intri nsic safety, controls, shu tdowns an d interlocks,
i ncl u d in Get
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These g en eral specificati ons rel ated to th e appl i cati on of th e eq u ipm en t assem bl y shal l be
docum en ted by th e m an u facturer.

4.2 Explosion protection specification s

I n ad d iti on to th e g en eral specifications of 4. 1 , if n ot specifi ed as part of th em , th e
m anufacturer sh al l d ocu m ent the fol l owi ng specifications rel ated to th e instal l ati on of th e
eq u i pm ent assem bl y by the en d -user:
– defau l t eq u i pm ent protecti on l evel (EPL) as defin ed i n I EC 60079-1 4, as a m in im um
req u irem ent;
– eq u i pm ent Grou p;
– tem perature cl assificati on or m axim um surface tem perature;
– all owances for dust l ayers as applicable;
– Specific Con di tions of U se (“X” con d iti ons).
4.3 Hazardous area classification related to the equipment assembly
4.3.1 General
There are two aspects of area classification th at can im pact eq ui pm en t assem bl ies. The first
is d u e to the area i n wh i ch the equ i pm ent assem bl y is to be i nstal led , an d the secon d is d u e
to an y source of rel ease from th e equ i pm en t assem bl y.

I t is n ot a requ irem en t of th is d ocum ent to verify ei th er of th ese area classifi cati ons.

The m anufacturer sh all docum en t the su itabil i ty of th e eq u ipm en t assem bl y for the intend ed
en d-site h azard ou s area cl assification an d for th e defin ed i nstal lation con di ti ons.
I EC TS 60079-46: 201 7 © I EC 201 7 –9–

4.3.2 Equipmen t assembly with its own source of release

I f the eq u i pm ent assem bl y h as its own source of release, th e m an ufacturer sh al l also
docum en t:
– th e h azard ou s area classificati on id en tifyi n g an y sou rce of release, factors rel evant to th e
sources of rel ease (e. g. rel ease rate, orifice si ze, operatin g m od e, fai l u re m od e,
recom m end ati on for m anag em ent of th e h azard ) and an y oth er i nform ati on relevant to
qu antifyi n g th e hazard an d th e m eth od ol og y and an y references used to arrive at th e
cl assification ;
– an y con d iti ons defin ed by th e m anufacturer su ch th at th e su itabil i ty of the eq u ipm en t
assem bl y for th e h azard ous area classification rem ains val i d.
The cl assification of h azard ou s areas sh al l be i n accord ance with I EC 60079-1 0-1 or
I EC 60079-1 0-2 as applicabl e. Th is cl assificati on m ay be provid ed by th e end-user.

4.4 Competencies
For eq ui pm en t assem bl i es su bjected to type verification, th e m an u factu ri ng process and th e
com petency of th e related person nel sh al l conform to I SO/I EC 80079-34.

For eq u i pm ent assem bl ies su bjected to u n it verificati on , com petency of th e personn el

perform in g th e production processes is verified by conform ity of the eq u ipm ent assem bl y wi th
th is d ocum ent. Th e verifyin g party sh all be com petent in th e explosion protecti on aspects of
th e assem bl y bein g verifi ed .

When equ i pm en t assem blies are su bj ected to u n it verification, th e verifyi ng party shal l h ave
evid ence of com petency throug h an in depen d en t party or system .

Docum entation regard i ng the above shal l be i ncl u ded with each eq u i pm ent assem bl y.

N OTE An exam pl e of su i tabl e d ocu m entati on to d em onstrate the com peten cy req u i red for type veri fi cati on wou l d
be a record of cu rrent assessm ent to I SO/I EC 80079-34 by a com petent thi rd -party assessor, an d for u ni t
veri fi cati on i t cou l d be a cu rren t certi fi cate i ssu ed by a com petent thi rd -party assessor.

5 Design of equipment assemblies

5.1 General
The sel ection, i nstall ation an d inspecti on of th e electrical equ i pm ent i n an assem bl y sh all be
in accord ance with I EC 60079-1 4, except as m od ifi ed by th is d ocu m ent.

5.2 Ex Equ ipment

5.2.1 Individual items
I n d i vid u al i tem s th at com prise th e eq u ipm en t assem bl y shal l conform to th e I EC 60079 seri es
or I SO 80079 series stan d ard s based on the associated ig n iti on risks, an d sh al l h ave
ind i vi du al Ex Eq u i pm ent certificates or be assessed as part of th e assem bl y.

Al l ind i vi du al i tem s sh al l be su itabl y rated for th e appl icati on an d be util i zed in accord ance
wi th th e m an u facturer’s i nstru ctions.

Where item s oth er th an su itabl y rated Ex Eq u ipm en t were not separatel y assessed as part of
Ex Eq uipm en t, an assessm ent, inclu d in g further tests accord in g I EC 60079 seri es or
I SO 80079 seri es stand ard s if necessary, sh al l be m ad e as part of the equ i pm en t assem bl y
eval u ati on .

N OTE I tem s other than E x Eq u i pm ent can i ncl u d e, for exam pl e, E x Com pon en ts, si m pl e apparatu s, g eneral
i nd u stri al prod u cts wi thi n an E x “d ” or E x “p” en cl osu re, G rou p I eq u i pm ent u sed i n a Grou p I I appl i cati on .
 – 10 – I EC TS 60079-46: 201 7 © I EC 201 7

5.2.2 Specific Conditions of Use as specified on certificates

Al l Specific Con d iti ons of U se as specified on eq u i pm ent certificates sh al l be consi dered and
th eir appl ication docu m ented by th e m anufacturer as fol lows:
– I f d irectl y related to th e eq u ipm ent assem bl y, how th ey were satisfied in th e equ ipm en t
assem bl y.
– I f d irectl y rel ated to th e equ ipm en t assem bl y, but not satisfied i n th e equ i pm ent assem bl y,
how they wi l l be abl e to be satisfied i n the en d-user si te i nstall ati on.
– I f n ot d irectl y related to the eq u ipm ent assem bl y, wh y th ey were n ot d irectl y rel ated.
Specific Con d iti ons of U se th at are rel ated to i tem s of eq u ipm en t form ing the eq u i pm ent
assem bl y, that are n ot satisfied in th e eq u ipm en t assem bl y, bu t abl e to be satisfi ed i n the
en d-user site i nstal lation, shal l be i nclu d ed or ad dressed , on the eq u ipm en t assem bl y
certificate.

5.2.3 Item list

An item list sh al l be prepared by th e m an u factu rer of th e equ ipm ent assem bl y an d incl u d ed as
part of each eq u ipm en t assem bl y certificate.

This l ist sh al l incl u de an i n ven tory of al l Ex Equ ipm ent, i ncl u d in g Ex Com ponen ts th at were
assessed as part of th is eq u i pm ent assem bl y, i ncorporated i nto the eq u ipm ent assem bl y.

Reg ard in g each i tem on th is l ist, d etails shal l be provid ed th at in d icate th e:

– descri pti on (type of d evice);
– m anufacturer's
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– i dentification n um ber of each item (e. g . tag n um ber);
– Ex Eq u ipm en t certificate num ber, i ncl ud i n g issu e num ber;
– Ex Com pon ent certificate num ber, incl ud i ng issu e nu m ber, for Ex Com ponen ts th at were
assessed as part of th is eq u i pm ent assem bl y;
– type of protecti on , Grou p an d tem peratu re classificati on (wh ich m ay be provi d ed as th e
com pl ete Ex m arking stri ng);
– am bi en t tem perature ran ge;
– i ngress protecti on (I P Code), if appl icabl e.
5.3 Other items
Reg ard i n g oth er i tem s th at m ay be relevant to expl osi on protection for th e equ ipm ent
assem bl y (e. g. non-m etal l ic parts such as h ou sin g s, h and l es, cabl e trays, roll ers, fl ui d tu bi ng),
detai ls sh al l be provi d ed th at in d icate th e:
– descri pti on (type of d evice);
– m anufacturer's n am e an d m odel or part n um ber (type d esign ation);
– descri pti on of an y expl osi on risk i n vol ved and h ow th e risks are m itig ated .
N OTE I SO 80079-36 provi d es gu i d an ce regard i ng i g ni ti on ri sk assessm en ts appl i cabl e to both n on-el ectri cal an d
el ectri cal i gn i ti on ri sks.

5.4 Wiring system

Desi gn of the wiri n g system for th e eq u i pm ent assem bl y that i nterconn ects the Ex Eq ui pm en t
shal l incorporate wiring m ethods that conform to I EC 60079-1 4.

I nform ati on shal l be provid ed by th e m an u factu rer for each wirin g m eth od , i nclu d in g
term ination m eans, used as part of each eq u ipm en t assem bl y.
I EC TS 60079-46: 201 7 © I EC 201 7 – 11 –

Reg ard i n g th is i nform ati on, d etails sh all be provi d ed th at in d icate th e:

– type of cable or con du i t constructi on desi g nation (e. g. tray cabl e, m arin e cabl e, rig id m etal
con d u it, fl exibl e con du it);
– num ber an d size of cond u ctor cores, if applicable;
– tem perature ratin gs, if applicable;
– electrical param eters (su ch as ind uctance an d capacitance per m eter, i n d uctance to
resistance ratio) for in trin sical l y safe system s;
– en vironm ental com pati bi l ity i n accord ance with 4. 1 (such as ou td oor use, m oisture,
flexi bi l i ty, vi bration, ch em ical com pati bil i ty);
– verificati on that entry d evices an d fi ttings (e. g. cable g l an ds, con d u it seal ing d evices,
con d u it el bows) are appropriate for the Type of Protecti on of th e i ntercon n ected item of Ex
Equ ipm ent.
I t is not a req u irem ent of th is d ocum ent th at th e conform i ty of th e cabl e specificati ons be
verified by testi n g, except as requ ired by I EC 60079-1 4.

5. 5 Drawin g s

Drawi n gs sh al l be provi ded by th e m an ufacturer to cover all rel evan t i nform ation for the
assem bl y i ncl ud i ng d etails foun d in oth er I SO 80079 an d I EC 60079 seri es stan d ards. Th is
inform ation m ay inclu d e, as appl icabl e:
– l ayouts;
– m echan ical d etai ls;
– sing l e l i ne d i agram s;
– intercon n ecti on d i agram s i ncl ud i ng wire an d core d esig nations;
– cabl e and con d u it d etai ls;
– for in trinsical l y safe wiri ng system s a “system s d escripti ve d ocum en t” as defin ed i n
I EC 60079-25 an d I EC 60079-1 4.

6 Con structi on and assembl y

6. 1 G en eral

The m an ufacturer sh al l provid e m echan ical layou t drawi n gs of th e equ ipm ent assem bl y.

6. 2 Di sassem bl y an d reassem bl y

The fol l owi n g is perm itted to be perform ed by th e m anufacturer of th e equ i pm en t assem bl y,

as l on g as it is docum en ted in th e equ ipm ent assem bl y assessm en t records:
– d isassem bl y i n th e factory of a com pl eted equ i pm en t assem bl y;
– transportation of the d isassem bl ed eq u ipm ent assem bl y to th e en d -user site, an d;
– reassem bl y of the eq u ipm ent assem bl y at th e en d -u ser site.
Alternativel y, th e reassem bl y acti vity is perm itted to be perform ed u n der the responsi bi l ity of
th e m anufacturer, as l ong as th is is docum en ted i n the equ ipm ent assem bl y assessm en t
record s.

N OTE Local reg u l ati on s m i g ht con si d er th e reassem bl y of an eq u i pm ent assem bl y i n the fi el d at th e en d -si te as
an i nstal l ati on acti vi ty, an d th erefore reassem bl y cou l d be su bj ect to l ocal i n stal l ati on reg u l ati on s.
 – 12 – I EC TS 60079-46: 201 7 © I EC 201 7

6.3 System interfaces

The need for system i nterfaces rel ated to the expl osion protecti on shal l be add ressed by th e
m anufacturer as part of the eq u ipm ent assem bl y docum en tation . See 4. 1 .

When th ese in terfaces are in tegral to th e equ ipm ent assem bl y, they are ad dressed as
ind icated i n th is d ocum ent.

When th ese in terfaces are to be l ocated rem otel y from th e eq u ipm ent assem bl y, th e
m anufacturer sh al l i ncl u d e instructi ons as to th e n ecessary ch aracteristics of th ese in terfaces.

6.4 Ignition hazard assessment

The m an ufacturer sh al l perform an d d ocum ent an assessm en t of al l ig n ition h azards th at
m ight h ave been caused by th e com bi nation of th e Ex Eq u i pm ent i n accordance wi th
I SO 80079-36 for both non-electrical an d el ectrical risks. Ad di tion all y, a risk assessm ent
m ethod olog y specifi ed by the en d -user m ay also be perform ed.

The docum en tation sh al l ad dress th e risks as fol l ows:

– i gn i tion hazards d irectl y related to th e equ ipm ent assem bl y, an d h ow they were m itig ated
i n th e eq u i pm en t assem bl y;
– i gn i ti on h azards d irectl y related to th e eq u ipm en t assem bl y, not m itig ated in the equ ipm ent
assem bl y, but abl e to be m iti gated i n th e en d-user si te i nstall ati on.
For i gn i ti on hazards th at are n ot m i ti g ated in th e equ ipm en t assem bl y, bu t that are able to be
m itigated in the en d-user site instal l ati on , the equipment assembly certificate number shall include
the "X" suffix in accordance with the marking requirements of IEC 60079-0 and the Specific Conditions
of Use shall Getbe listed
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I g n iti on h azards for each item of Ex Equ i pm en t are ad d ressed by th e Ex Equ ipm ent
certificates, and th erefore n eed n ot be reassessed .

The verifier sh al l confirm th at the m anu factu rer h as carried ou t an i g n iti on hazard assessm en t
an d d ocu m ented con trol m easures an d an y resi du al risk.

6.5 Calculations
The m an ufacturer sh al l provi d e al l calcu l ati ons an d safety param eters (such as tri p setti ngs
on a m otor overl oad , expl osi on rel ief calcu l ati ons, etc. ) rel evan t to th e expl osion protection of
eq u ipm ent assem bl y i n accord ance wi th I EC 60079-1 4, and th e appl icable Type of Protecti on
stan dards if n ot ad dressed by I EC 60079-1 4.

Calcu lations relevant to th e expl osi on protecti on of equ ipm en t assem bli es m ay i n cl u d e
m axim um power d issipati on for increased safety “e” encl osures, cabl e rati ng wi th th e settin gs
of the overload protectin g circu i t breakers an d i ntri nsical l y safe l oop anal ysis (also referred to
as d escri pti ve system d ocu m ents or con trol d rawi ngs).

N OTE I t i s not a req u i rem ent of th i s d ocu m en t th at the cal cu l ati ons for rem otel y l ocated i tem s be veri fi ed .

6.6 Inspection & testing

I nspecti on an d testin g of the en ti re eq u ipm en t assem bl y after assem bl y shal l be perform ed
an d d ocum ented by th e m anufacturer.

The electrical aspects of th e assem bl y sh al l be i nspected an d tested i n accord ance wi th

I EC 60079-1 4, wi th the n on-el ectrical aspects ad dressed in accord ance wi th the ig n iti on
hazard assessm ent in 6. 4.
I EC TS 60079-46: 201 7 © I EC 201 7 – 13 –

When disassem bl y an d reassem bl y i s in vol ved , th e eq ui pm en t assem bl y shal l be subj ected to

an i nspection an d testin g an d d ocum en ted eith er en tirel y after reassem bl y, or parti al l y pri or to
d isassem bl y an d parti al after reassem bl y.

6.7 Validation and documentation

6.7.1 General
Verificati on of an equ ipm en t assem bl y’ s conform ity to th e d esig n drawin gs an d specifications
shal l i ncl u d e:
– confirm ation th at al l Ex Eq u i pm en t on th e assem bl y is i den tified i n th e docu m entation and
th at th e d ocu m en tation m atch es th e assem bl y;
– verificati on of the con ten t of th e i tem list (see 5. 2. 3)
Assessm ent of the assem bl y sh al l i nclu d e:
– confirm ation th at each Ex Eq u i pm ent, incl u d in g Ex Com pon en ts th at were assessed as
part of th is eq ui pm en t, is appropriate for th e appl icati on (e. g. rati ngs m atch operati n g
con d iti ons);
– confirm ation that Specifi c Con d iti ons of U se for Ex Eq u ipm en t are ei th er ad dressed in th e
assem bl y or passed on to th e en d-u ser;
– confirm ation th at th e Sched u le of Lim itati ons for Ex Com pon en ts th at were assessed as
part of th is eq u i pm ent assem bl y are either ad d ressed in the assem bl y or passed on to the
en d-user, i ncl ud i n g detai l s reg ard i n g th e assessm en t;
– inspection of th e assem bl y is com pleted in accordance with 6. 6, and th at
non-conform ances are corrected;
– i nspecti on of th e assem bl y to ensure th at i t can be i nstal led i n accord ance wi th
I EC 60079-1 4 (incl u din g an y l ocal i nstal lati on criteri a);
– review of the instru ctions for each pi ece of Ex Eq u ipm en t to confirm proper appl ication of
th e Ex Eq u ipm ent.
The fi n al docum en tation package for an eq u ipm en t assem bl y shal l incl ud e the fol lowin g :
- gen eral specifications rel ated to th e appl ication of th e equ i pm en t assem bl y (see 4. 1 );
- expl osion protection specifications rel ated to th e instal lation of the eq u i pm en t assem bl y b y
th e end-u ser (see 4. 2);
- su itabi l ity of th e eq u i pm ent assem bl y for th e en d-site h azardous area cl assi ficati on and for
th e i nstal lation con d itions d efi n ed by th e end -user (see 4. 3. 1 );
- d etails reg ardi n g an y sou rces of release (see 4. 3. 2);
- com petencies associated wi th the related m an u factu ri n g process person nel or verifyi n g
party as appl icable (see 4. 4);
– detai ls reg ard in g item s relevant to th e expl osion protection of th e equ i pm en t assem bl y as
fol l ows:
• acti ons reg ard in g al l Specific Cond iti ons of U se as specifi ed on eq u ipm en t (5. 2. 2)
• item l ist of al l Ex Eq u i pm en t (see 5. 2. 3)
• detai ls reg ardi n g oth er i tem s th at m ay be rel evant to th e expl osi on protection of th e
eq u ipm ent assem bl y (see 5. 3);
– i nform ation reg ard in g each wiri ng m eth od , incl ud ing term ination m eans, used as part of
th e equ i pm en t assem bl y (see 5. 4);
– drawi n gs of th e eq u ipm ent assem bl y (see 5. 5);
– m echan ical l ayou t drawi n gs of th e equ ipm ent assem bl y (see 6. 1 );
– an y provisi ons for earth in g an d bon d in g of th e eq u ipm en t assem bl y as req u ired for
en d-user site i nstal l ati on ;
 – 14 – I EC TS 60079-46: 201 7 © I EC 201 7

– detai ls reg ard in g d isassem bl y an d reassem bl y at th e en d-user site of the eq u ipm ent
assem bl y, either d irectl y by the m an u facturer of th e eq u ipm en t assem bl y or u n d er th e
responsibi l ity of the m an ufacturer, if applicable (see 6. 2);
– th e need for system in terfaces related to th e explosion protection, ei th er i ntegral to th e
eq u ipm ent assem bl y or l ocated rem otel y, if applicabl e (see 6. 3);
– an y resi d u al risk i den tifi ed by the ig n iti on hazard assessm ent (see 6. 4);
– all calcu lations an d safety param eters relevant to th e expl osion protection of eq u ipm en t
assem bl y (see 6. 5);
– resu l ts of th e inspection an d testing (see 6. 6);
– oth er m aterial specifications (see 6. 7. 2);
– i nstructions for each piece of Ex Eq ui pm en t;
– i nstructions for th e eq u i pm ent assem bl y (see 6. 8);
– access to eq ui pm en t;
– en vironm ental controls;
– all owances for fi eld cabl ing ;
– I n gress Protecti on assessm ent resul ts.
6.7.2 Other material specifications
Materials used oth er than m ateri als that are part of an i tem of Ex Eq u i pm ent, i ncl u d in g Ex
Com pon en ts th at were assessed as part of th is equ ipm en t assem bl y, an d that are related to
th e expl osi on protection of th e eq u ipm en t assem bl y, shal l be verifi ed for com pl i ance with th e
appl icabl e requ irem ents of I EC 60079-0 an d I SO 80079-36.

6.7.3 Schedule Documents

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Docu m ents sufficient to defin e th e eq u i pm ent assem bl y sh al l be referenced on the eq u ipm ent
assem bl y certificate (e. g. g eneral assem bl y drawi ng th at id entifi es the Ex Equ i pm ent used).

6.8 Instructions
I n add i ti on to th e req u irem en ts in I EC 60079-0, I EC 60079-1 4 an d I SO 80079-36, the
m anufactu rer of the eq u i pm ent assem bl y sh all prepare i nstructi ons th at ad dress the fol l owi n g,
as appl icabl e:
– specific cond i tions of use that are not satisfied i n the equ i pm ent assem bl y, but th at are
abl e to be satisfi ed i n th e en d-user si te i nstall ati on ;
– characteristics of in terfaces that are rel ated to the expl osion protecti on and th at are to be
l ocated rem otel y from th e eq u i pm ent assem bl y;
– an y i d en tified risks that are n ot m iti gated in th e eq u i pm ent assem bl y, an d that are abl e to
be satisfied i n th e end -u ser site instal l ati on;
– u ser-specifi ed desig n req u irem en ts;
– all req u ired m arkin gs of the assem bl y an d l ocati on s of th ese m arkin gs;
– expl osion protection specifications related to th e i nstal lation of th e equ i pm en t assem bl y by
th e end-user (see 4. 2).

7 Certificate
I n ad d ition to the req u irem ents in I EC 60079-0 an d I SO 80079-36, th e certificate for th e
eq u i pm ent assem bl y shal l address the fol l owi ng , as appl icabl e:
– assem bl y at th e factory by th e m an ufacturer of th e eq ui pm en t assem bl y;
– assem bl y at th e en d-site d irectl y by the m anufacturer or u n der th e responsibili ty of th e
m anufacturer of th e eq ui pm ent assem bl y;
I EC TS 60079-46: 201 7 © I EC 201 7 – 15 –

– d isassem bl y of an eq u i pm ent assem bl y at the factory an d reassem bl y at th e en d-si te

d irectl y by th e m anu factu rer or u n d er th e responsi bil i ty of th e m an ufacturer;
– wh ere th e assem bl y has an intern al source of rel ease, th e certificate sh al l state th at the
cl assification for th e internal source of rel ease h as not been verified by the assessor, if
su ch is th e case;
– th e specific cl auses of I EC 60079-1 4 that h ave been satisfi ed ;
– th e l evel of i nspection com pleted on th e eq ui pm en t assem bl y;
– wh ere item s oth er th an Ex eq ui pm en t were in cl ud ed as part of th e assem bl y, the
certificate sh al l l ist each su ch item an d in d icate th e appl icabl e m arkin g on each i tem .

8 Marking
8.1 General
The eq u ipm en t assem bl y shal l be m arked i n accord ance with I EC 60079-0 an d I SO 80079-36,
except for th e sym bol for each type (or l evel ) of protection used , wh ich is repl aced by
‘60079-46’. As th e types of protecti on are n ot i ncl ud ed on th e m arking , th e eq u ipm en t
protecti on level (EPL) for the com plete eq u i pm ent assem bl y sh al l be m arked .

The m anufacturer’s nam e th at appears on th e assem bl y m arkin g sh all be that of the

eq u i pm ent assem bl er.

The Eq ui pm en t Grou p, tem perature cl assification (or m axim um surface tem perature),
eq u i pm ent protection l evel (EPL), an d am bi ent tem perature rang e, alon g wi th option al ingress
protection (I P Code) m arkings for the eq u ipm ent assem bl y sh al l be d eterm ined as d etailed
bel ow. Separate determ inati on of th is m arking con ten t is n eed ed for explosi ve g as
atm osph eres an d explosive d ust atm osph eres, as appl icabl e.

The eq ui pm en t assem bl y m arkin gs are not in ten d ed to sim pl y be a repeat of m arkin gs from
th e incorporated Ex Eq u i pm ent, incl ud in g Ex Com pon en ts th at were assessed as part of th is
eq u i pm ent assem bl y. The m arkin gs for th e equ ipm en t assem bl y are to be determ in ed
specifical l y for th e eq u ipm ent assem bl y based on the req u irem ents of this docum en t.

I tem s wh ich req uired ad d ition al assessm ent as a part of th e assem bl y sh all have an extern al
m arking, incl ud in g Type of Protection an d referen ce to th e assem bl y certifi cate n u m ber.

The certificate sh al l i nclu de a Specific Cond i tion of U se th at th e instal lati on is requ ired to be
in accord ance with th e i n struction d ocum ents.

I f an assem bl y has parts that have different cl assifications or EPLs, th e m arkin gs an d

instru ctions shal l i d en tify th ese.

8.2 Determining Group marking

The Eq u i pm en t Group m arkin gs for th e eq ui pm en t assem bl y shal l be based on th e fol l owi n g:
– th e l owest (e. g . I I B is lower than I I C) Grou p m arking of al l of the Ex Eq u i pm ent, incl u d in g
Ex Com pon en ts th at were assessed as part of th is eq u ipm ent assem bl y, for th e in vol ved
expl osive atm osph eres, as appl icabl e:
– oth er attribu tes of th e equ i pm en t assem bl y construction that m ay affect th e Eq u ipm en t
Group m arkin g (e. g. m aterial com position of external surfaces).
N OTE I t i s possi bl e to have d i fferent area cl assi fi cati on s appl i cabl e to th e sam e eq u i pm en t assem bl y, su ch as
d u e to an i n tern al sou rce of rel ease.
 – 16 – I EC TS 60079-46: 201 7 © I EC 201 7

8.3 Determining temperature class or maximu m su rface temperature marking

The tem perature cl ass or m axim um surface tem perature m arkin g for th e eq u ipm en t assem bl y
shal l be based on the fol l owing :
– th e l owest tem perature cl ass cod e (e. g. T3 is l ower th an T6) or h i gh est maximum surface
temperature of an y of th e Ex Eq u i pm ent, incl u d in g Ex Com ponen ts th at were assessed as
part of this eq ui pm en t assem bl y, for th e in vol ved expl osive atm ospheres, as appl icable, as
l on g as the item s are operati ng with i n their specified am bi en t tem perature ran g e;
– oth er attributes of th e eq u i pm en t assem bl y construction that m ay affect the tem perature
cl ass or m axim um surface tem perature m arking (e. g . h ot surfaces).
To determ in e if th e Ex Equ ipm en t is operati ng wi th i n each item ’s specified am bi en t
tem perature ran g e, a rou tin e tem peratu re test m ay be perform ed i n accord ance wi th
I EC 60079-0. Sh ou l d an item exceed its specifi ed am bi en t tem perature ran ge, th en correcti ve
acti ons are req u ired .

N OTE U se of a m otor wi th a converter, i f the m otor i s not d esi gn ed for operati on from a converter, can affect the
tem peratu re ri se of the m otor.

8.4 Determining Equipment Protection Level (EPL) marking

The EPL m arkin g for th e eq u i pm ent assem bl y shal l be based on th e foll owi ng :
– th e EPL m arkin g for the l owest Level of Protection of an y of the Ex Eq ui pm ent, incl u d in g
Ex Com pon en ts th at were assessed as part of th is eq u i pm ent assem bl y, for th e in vol ved
expl osi ve atm osph eres, as appl icabl e;
– oth er attribu tes of th e eq u i pm ent assem bl y constructi on th at m ay affect th e Level of
Protecti on (e. g. external encl osu re m ateri al surface area).
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For Ex Equ ipm en t th at i s n ot m arked with an EPL, th e d efau l t rel ati onsh ip between types of
protection an d EPLs from I EC 60079-1 4 sh all be used to d eterm i ne the EPL for th at i tem of
Ex Eq u ipm en t.

8.5 Determining ambient temperatu re range marking

The am bien t tem peratu re ran g e m arkin g for the eq u ipm ent assem bl y sh al l be based on th e
fol l owi ng :
– l owest upper m axim um tem perature th at is com m on to al l item s and th e h igh est l ower
m inim um tem perature th at is com m on to al l item s that were assessed as part of th is
eq u ipm ent assem bl y;
– oth er attribu tes of the eq u i pm ent assem bl y constru ction th at m ay affect th e am bi en t
tem perature ran ge (e. g. cabl e am bient ratin gs).
Measures m ay be req u ired to m ai n tain th e Ex Equ i pm ent wi th in i ts m arked am bien t
tem perature ran ge.

8.6 Determining ingress protection (IP Code) ratin g

Assig nm en t of th e I P rating of th e assem bl y m ay be m ad e based on the rati ng of th e
ind ivid u al item s of eq u ipm ent and the i ntercon nectin g accessori es. J ustificati on for th e
assig n ed rati ngs sh al l be d ocum ented.

Consid erati on m ay be g i ven to Ex Eq u ipm ent used i n the assem bl y th at is afford ed

suppl em ental protecti on by th e assem bl y constru ction (e. g . a pre-m an ufactured room wh ere
som e i tem s of th e assem bl y are m ou n ted with i n th e room an d oth er i tem s are m ou nted
external l y to th e room ).

___________
I N TE RN ATI O N AL

E LE CTRO TE CH N I CAL

CO M M I S S I O N

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