KROHNE M10 Converter H250-H 54 Ex II2G EN - Manual (Page 10)

Signal converter M10-EEx d – Supplementary instructions
11/2002
10
8.2 Dismantling
8.2.1 General
Should it prove necessary to open the Flameproof Enclosure of the electronics compartment in the
presence of an explosive atmosphere, the device must first be disconnected from supply. Be sure
to allow the waiting time printed on the nameplate of the signal converter of:
• 8 minutes for temperature classes T6 and T5
to elapse before opening the Flameproof Enclosure. There is no waiting time for any of the other
temperature classes.
Before connecting or disconnecting the device interconnecting cables, make sure that all cables
leading into the signal converter are isolated from the ground (reference potential) of the
hazardous area. This also applies to safety conductors (PE), functional ground (FE) and the
equipotential bonding conductor (PA).
After any maintenance work has been carried out, be sure to regrease the thread of the
flameproof cover of the signal converter, including cover gaskets, with a resin-free and acid-free
all-purpose grease.
8.2.2 Replacement of signal converter / display
Disconnect the device from supply before opening the Flameproof Enclosure. Be sure to follow the
procedure described in Section 8.2.1.
Note :
Only same-type displays and complete converter housings may be replaced.
Individual device inserts may not be replaced! Compare nameplates when
replacing the signal converter. Only same-type signal converters to be replaced.
The display can be replaced after opening the Flameproof Enclosure of the electronics
compartment. To replace a complete display, take note of the information given in Section 5.1.4.
The measuring tube of the variable-area flowmeter can in both cases remain in the pipeline, also
when product is flowing.
Note :
Always renew defective fastening clips (prisms) between measuring tube and
display housing.
8.2.3 Replacement of complete device
Please refer to Sections 8.2.1 and 8.2.2. In addition, make sure that all process connections and
the pipeline are non-pressurized and free of product. In the case of environmentally critical
substances, carefully decontaminate the wetted parts of the flange system after dismantling.