KROHNE BM 70A EEx EN - Manual (Page 6)

07/2010 - 4000662402 MA BM70x-Ex-AD-R02-en www.krohne.com 6
3. Main safety-relevant characteristics
3.1. Signal converter
The BM 70..-Ex level gauges consist in each case of a combination of signal converter and flange
system. The main characteristics of the explosion-protected signal converter are described below.
3.1.1. Category / Zone allocation
The signal converter part of the BM 70..-Ex is basically designed in Category 2 for application in
Zone 1.
3.1.2. Type of protection
BM 70..-Ex with non-intrinsically safe I/O functions
Variant Device part Type of protection Symbol
Electronics compartment Flameproof Enclosure
Terminal compartment Increased Safety BM 70./E-Ex
Pin coupler compartment Increased Safety
Ex de
Electronics compartment Flameproof Enclosure
Terminal compartment Flameproof Enclosure BM 70./D-Ex
Pin coupler compartment Increased Safety
Ex de
BM 70Ai/.-Ex and BM 70Pi/.-Ex with intrinsically safe I/O functions
Variant Device part Type of protection Symbol
Electronics compartment Flameproof Enclosure
Terminal compartment Increased Safety BM 70.i/E-Ex
Pin coupler compartment Increased Safety
Ex de [ia]
Electronics compartment Flameproof Enclosure
Terminal compartment Flameproof Enclosure BM 70.i/D-Ex
Pin coupler compartment Increased Safety
Ex de [ia]
BM 702-Ex / BM 702 A-Ex with intrinsically safe I/O functions
Variant Device part Type of protection Symbol
Electronics compartment intrinsic safety
BM 702i-Ex
Terminal compartment intrinsic safety
Ex ia
3.1.3. Special lock
For all device variants BM 70A./.-Ex, BM 70P./.-Ex and BM 700/.-Ex, the sealing covers of terminal
compartment and electronics compartment are secured by special locks. The locking screw requires
use of an Allan key (4 mm size).