KROHNE OPTISONIC 3400 CSA EN - Manual (Page 25)

MAINTENANCE AND SERVICE
5
25
OPTISONIC 3400
www.krohne.com 10/2013 - 7313222100 - AD CSA OPTISONIC 3400 -en- R01
5.1 Maintenance
The flowmeters are maintenance free with respect to the flowmetering properties. Within the
scope of periodic inspections required for electrical equipment installed in hazardous areas it is
recommended to check the flameproof converter housing and covers for signs of damage or
corrosion.
For information about the explosion-proof joints please contact your KROHNE representative.
The four M6 bolts to screw the MH300-Ex housing have a strength of 700N/mm2.
5.2 Before and after opening
Before opening:
• Make absolutely sure that there is no explosion hazard!
• Make sure that all connecting cables are safely isolated from all external sources!
• Allow the electronics to de-energize before opening the electronics compartment of the
converter housing. Wait at least 35 minutes for T6 and 10 minutes for T5 before opening.
When the instructions above are strictly followed, the display cover (includes glass window) of
the electronics compartment may be removed. First unscrew the head screw with internal
hexagon socket set (size M4) of the interlocking device by a No. 3 Allen key, until the cover can
rotate freely.
After opening:
• Before the cover is screwed back onto the housing, the screw-thread must be clean and well-
greased with an acid and resin-free grease, e.g. PTFE grease.
• Screw the cover as tight as possible onto the housing by hand, until it cannot be opened by
hand anymore. Fixate the screw of the interlocking device tight with the No. 3 Allen key.
WARNING!
the following instructions must always be carefully followed, if the housing of the signal
converter has to be opened respectively closed again.