Technical data

Use in Hazardous Environments • 321
Classification Meeting CENELEC and IEC
WAGO-I/O-SYSTEM 750
BACnet/IP Controller
9.3.5 Types of Ignition Protection
Ignition protection defines the special measures to be taken for electrical
components in order to prevent the ignition of surrounding explosive
atmospheres. For this reason a differentiation is made between the following
types of ignition protection:
Tab. 9-5: Types of Ignition Protection
Identifi-
cation
CENELEC standard IEC standard Explanation Application
Ex o
EN 60079-6 IEC 60079-6
Oil encapsulation Zone 1 + 2
Ex p
EN 60079-2 IEC 60079-2
Overpressure
encapsulation
Zone 1 + 2
Ex q
EN 60079-5 IEC 60079-5
Sand encapsulation Zone 1 + 2
Ex d
EN 60079-1 IEC 60079-1
Pressure resistant
encapsulation
Zone 1 + 2
Ex e
EN 60079-7 IEC 60079-7
Increased safety Zone 1 + 2
Ex m
EN 60079-18 IEC 60079-18
Cast encapsulation Zone 1 + 2
Ex i
EN 60079-11 (Device)
EN 60079-25 (System)
IEC 60079-11
Intrinsic safety Zone 0 + 1 + 2
Ex n
EN 60079-15 IEC 60079-15
Electrical
components for
zone 2 (see below)
Zone 2
Ignition protection “n" describes exclusively the use of explosion protected
electrical components in zone 2. This zone encompasses areas where
explosive atmospheres can only be expected to occur rarely or short-term. It
represents the transition between the area of zone 1, which requires an
explosion protection and safe area in which for instance welding is allowed at
any time.
Regulations covering these electrical components are being prepared on a
world-wide scale. Organizations such as the PTB in Germany certify that the
devices meet the requirements of the European standard EN 60079-15.
Type “n” ignition protection additionally requires electrical components to be
marked with the following extended identification:
• Non-sparking apparatus "nA"
Apparatus, which is designed so that the risk of occurrence of arcs or
sparks, which can give rise to an ignition hazard during normal operation,
is minimized.