KROHNE OPTISONIC 3400 Ex EN - Manual (Page 21)

ELECTRICAL CONNECTIONS
4
21
OPTISONIC 3400
www.krohne.com 10/2013 - 7312472200 - AD EX OPTISONIC 3400 -en- R02
4.2 Cable glands
The three cable entry holes in the MH-300-... housing have a M20x1.5 screw thread. Make sure
that the custom selected cable glands and/or stopping plugs have the same screw thread.
For use in gaseous hazardous areas: For use in gaseous hazardous areas: For use in gaseous hazardous areas: For use in gaseous hazardous areas: the chosen cable glands and/or stopping plugs, must have
the appropriate type of protection for the terminal compartment that is increased safety (Ex e) or
flameproof enclosure (Ex d). They MUST be suitable for the conditions of use and correctly
installed.
The flowmeter with the terminal compartment in type of protection increased safety “Ex e” is
factory supplied with two “Ex e” approved cable glands and one “Ex e” approved blanking element
(i.e. stopping plug).
4.3 Field Wiring
The wiring of instruments has to be in accordance with the requirements as specified in the
relevant national or international standard for electrical installations in hazardous areas, e.g.
EN 60079-14. Section 9 (wiring systems) of this standard applies to all types of protection.
Section 10 (additional requirements for type of protection “d” - flameproof enclosures), section
11 (additional requirements for type of protection “e” - increased safety) and section 12
(additional requirements for type of protection “i” - intrinsic safety) apply to respectively “Ex d”,
“
Ex e” and “Ex i” performed connection (terminal) compartments.
WARNING!
When the terminal compartment performed as flameproof enclosure
“ Ex d ” , the MH 300-..
housing is supplied with one “ Ex d ” approved stopping plug and two temporary plugs. The
temporary plugs are only intended for sealing the housing against entry of dust, moisture or else
during transport, handling and storage. These temporary plugs must be replaced by suitable
“
Ex
d ” approved cable glands, stopping plugs or conduit adapters with sealing devices before the
flowmeter is put into operation. Unused openings must be sealed by suitable certified plugs.