2. CENTUM and Explosion Protection Instrumentation
2-2
TI 33Q01J30-01E
2.2
Explosion Protection Construction that I/O
Devices of CENTUM Comply
As described in 2.1, countries define their own standards and rules regarding technical methods
for explosion protection. With CENTUM, NI, Ex “ec”, Type “n”, and intrinsic safety explosion
protection are adopted as explosion protection construction for the installation of FCS or node
unit in hazardous areas. The adoption of NI, Ex “ec”, and Type “n” with FIO and N-IO devices of
CENTUM allows FCS or node unit to be installed in Class II hazardous area (Division 2, Zone 2)
which covers most hazardous areas. This provides more variety of instrumentation.
With N-IO field enclosure, NI, and Ex “ec”, are adopted as explosion protection construction for
the installation of N-IO field enclosure in hazardous areas.
The adoption of NI allows N-IO field enclosure to be installed in Class II hazardous area (Division
2 or Zone 2).
N-IO devices are equipment compliant with intrinsic safety explosion protection and are the
modules that can be connected to the devices installed in Zone 0, Zone 1 and Zone 2 (Division 1,
Division 2).
To install FCS or node unit in a hazardous area, the node itself and the terminal board as well
as the I/O modules should acquire standards. The figure bellow shows one example of Ex “ec”/
Type “n” standard compliant devices. The devices shown in half-tone dot meshing and the cables
shown in heavy line are Ex “ec”/Type “n” compliant products. The same is with NI compliant
devices. FCS or node unit can be installed in Zone 2 (Division 2).
See the tables in Appendix for details of each CENTUM equipment and their approved
standards.
<Hazardous area Zone 2>
<Non-hazardous area>
F
OUNDATION
Fieldbus
ER Bus
ANB11S/ANB11D
/A2BE2D
AEA4D etc.
ESB Bus Node Unit
ANB10S/ANB10D/A2BE2D
Intrinsic safety
device
Intrinsic safety
device
Type “n”
Ex "ec" device
Field wiring
terminal for
Type "n"
F020201.ai
Terminal board
Signal cable
Power
supply
module
Optical ESB Bus
Repeater Master
Module
Optical ESB Bus
Repeater Slave
Module
Optical ESB Bus Node Unit
Cabinet
Optical ESB Bus
I/O module,
terminal block
*1
*1
*1
*1
Safety
Barrier (*2)
Safety
Barrier (*2)
*1
*1:
Explosion-proof wiring that is defined in EN 60079-14 and the rules/standards of each country or region.
*2:
Explosion-proof structure for hazardous area is required.
Figure Example of Ex “ec”/Type “n” Standard Compliant Devices
Dec .3, 2021-00
