User guide

EXI-01-04-06-14-GB
- 7 -
2.1. ATEX marking – symbols meaning
Electrical equipment -
compatible with one or
few kinds of anti-
explosion designs
Explosive atmosphere:
G – caused by gas,
vapor and mist.
D – caused by dust.
Symbol of the
used anti-explosion
design type
:
o – oil protection
p – gas protection with an
excess pressure
q – sand protection
d – flame-proof protection
e – strengthened design
ia -
intrinsically safe design
for operation in zone
0,1,2,
ib -
intrinsically safe design
for operation in zone 1,2,
Gas explosiveness group -
examples:
-IIA: propane (T1)
benzene (T3)
butane (T2)
ethanol (T2)
-IIB: ethylene (T2)
-IIC: acetylene (T2)
hydrogen (T1)
Temperature class –
surface max temperature
of the equipment parts that
are in touch with explosive
mixture
:
T1: 450
0
C
T2: 300
0
C
T3: 200
0
C
T4: 135
0
C
T5: 100
0
C
T6: 85
0
C
Temperature class
of the gas or vapor
auto ignition
:
T1: > 450
0
C
T2: > 300
0
C
T3: > 200
0
C
T4: > 135
0
C
T5: > 100
0
C
T6: > 85
0
C
Equipment group:
I – underground parts
of mines
II – all other places liable
to be endangered by
explosive atmospheres
Categories for group II
equipment:
1 - the device assures a
very high protection
level,
- to be operated in
zones 0,1,2
2 - the device assures a
high protection level,
- to be operated in
zones 1,2
3 - the device assures a
standard protection
level,
- to be operated in
zone 2
Security level
Gas atmosphere:
- Ga
- Gb
- Gc
Dust atmosphere:
- Da
- Db
- Dc