Page 96 - DMcatalogue2017

Low voltage AC motors

Explosive atmospheres

There are systems in place worldwide to classify explosive
atmospheres by zones, according to the risk posed by
explosive gas (‘G”) or dust (“D”).
M000168 M000169

Zone 2 (“G”) / 22 (“D”)
Abnormal condition
Presence of explosive atmosphere
only by accident, but not during
normal duty
Equipment protection level “c” required
Zone 1 (“G”) / 21 (“D”)
6 Occasionally
Incidental presence of explosive
atmosphere during normal duty
Equipment protection level “b” required

Zone 0 (“G”) / 20 (“D”)
Continously
Ex d(e) II... Gb Permanent presence of
CE... II 2 G Ex d/Ex de
CE... II 2 G Ex eGb
Ex e II... explosive atmosphere
CE... II 2 G Ex pGb Equipment protection level
Ex p II...
Ex t III... Db “a” required
CE... II 2 D Ex tD A21
CE... II 3 G Ex nA
Ex nA II...
CE... II 3 D Ex tD A22 Gc M000176
Ex t III... Dc

Classification of explosive atmospheres according to
CENELEC and IEC
The following standards define areas according to the
presence of gas or dust in the atmosphere:

IEC/EN 60079-10-1 Gas
IEC/EN 60079-10-2 Dust

Standard Installation Atex Directive Main motor
IEC 60079-0 Zone acc. to 94/9/EC Protection
EN 60079-0 IEC 60079-10-x Types
EN 60079-10-x
Group EPL Protection level Zones Equipment group Equipment category
I Ma very high NA I M1 NA
(Mines) Mb high (Mines) M2
II Ga very high 0 II 1G NA
(Gas) Gb high 1 (Surface) 2G Ex d/Ex de, Ex p, Ex e
Gc enhanced 2 3G Ex nA
III Da very high 20 1D NA
(Dust) Db high 21 2D Ex tb IP 65
Dc enhanced 22 3D Ex tc, IP 65/IP 55

96 Drives and controls, motors and mechanical power transmission catalogue