2 Safety
Maschinenfabrik Reinhausen GmbH 2020
16
4983703/01 EN
VACUTAP
®
VV-Ex
Explosion group (number 6)
EN/IEC
Gases, vapors (examples)
Min. ignition energy
(mJ)
IIA
Ammonia
-
IIA
Acetic acid, acetone, benzene, diesel,
ethane, ether, fuel oil, hexane, meth-
ane, petrol, petroleum, propane
0.18
IIB
Ethylene, isoprene, town gas
0.06
IIC
Acetylene, carbon disulfide, hydrogen
0.02
Table 7: Explosion groups
Temperature classes (number 7)
Temperature
class
Maximum equipment surface tem-
perature
Ignition temperature of
the flammable sub-
stances
T1
450°C
> 450°C
T2
300°C
> 300°C < 450°C
T3
200°C
> 200°C < 300°C
T4
135°C
> 135°C < 200°C
T5
100°C
> 100°C < 135°C
T6
85°C
> 85°C < 100°C
Table 8: Temperature classes
Equipment protection level (EPL) (number 8)
The EPL indicates the level of protection defined for a device based on the
level of probability of ignition and taking into account the differences be-
tween potentially explosive gas atmospheres, potentially explosive dust at-
mospheres, and potentially explosive atmospheres in mine workings af-
fected by firedamp.
2.4.2 Standards and regulations
The following standards and regulations apply to explosion-proof on-load
tap-changers:
▪ EN/IEC 60079-0: Equipment – General requirements
▪ EN/IEC 60079-6: Equipment protection by liquid immersion "o"
▪ EN/IEC 60079-7: Equipment protection by increased safety "e"
