KROHNE OPTISONIC 7300 Ex EN - Manual (Page 22)

4
ELECTRICAL CONNECTIONS
22
OPTISONIC 7300 / 8300
www.krohne.com 05/2012 - 7312262200 - AD EX OPTISONIC 7300/8300 R02
4.1 General
The display cover seals the electronics compartment of the converter housing and provides type
of protection “flameproof enclosure” (Ex d) according to EN 60079-1. The terminal compartment
is either in type of protection "increased safety" (Ex e) or performed as "flameproof enclosure"
(Ex d). The threaded joints formed by the covers and housing are a tight fit due to the
requirements for type of protection “flameproof enclosure”. Screw the covers on and off with
care and never use excessive force !
Keep the screw-threads free of dirt and well-greased (e.g. with PTFE grease). The grease will
help to prevent the threads from locking due to corrosion.
To unscrew the covers, first release the interlocking devices (one at each cover). Therefore
unscrew the M4 head screw with internal hexagon socket set using a No. 3 Allen key until the
interlocking device can be turned. After the covers are screwed back onto the housing, make
sure that the interlocking devices are properly refitted.
WARNING!
Allow the electronics to de-energize before opening the electronics compartment of the flow
converter housing. Wait at least 35 minutes for T6 and 10 minutes for T5 before opening.