KROHNE BM 100A ATEX EN - Manual (Page 13)

Section 6 - Service / Maintenance
10/2001 BM 100 A ATEX 13
6HUYLFHPDLQWHQDQFH
The device has no maintenance requirement when used for the intended purpose and in standard
applications.
6.1 Signal converter
Disconnect from power before starting work!
Should it prove necessary to open the flameproof enclosure or the electronics compartment in the
presence of an explosive atmosphere, allow the waiting time specified on the nameplate of the
signal converter to elapse first:
•
27 min for Temperature Class T6
•
12 min for Temperature Class T5
Before connecting or disconnecting the electrical interconnecting cables, make sure that all
cables leading into the signal converter are isolated from the ground (reference potential) of the
hazardous location. This also applies to protective conductors (PE) and equipotential bonding
conductors (PA).
After carrying out any maintenance work, always regrease the flameproof cover thread of the
signal converter housing, including the cover gaskets, with a resin-free and acid-free all-purpose
grease.
Dismantling of the electronic unit is described in the standard Installation and Operating
Instructions. Use only same-construction units with identical supply voltage and configuration of
the output modules.
i
Within the scope of checks required to be carried out in hazardous locations to maintain
systems in proper working order, carry out the following visual inspections at regular
intervals:
•
Check housing, cables entries and incoming cables for signs of corrosion and damage.
•
Check the tank connections for leakages.
6.2 Probes
The probes do not require any maintenance when used for the intended purpose and under
normal operating conditions. However, heavy deposits on the probe can cause measurement
deviations or faulty operation.
If the probe is dirty, clean according to the directions given in the standard Installation and
Operating Instructions. When dismantling the probe, be aware of working conditions (e.g. check
for presence of flammable liquid and/or potentially explosive atmosphere in or around the tank,
pressurized tank, etc.).
6.3 Replacement of complete device
Make quite sure that all process connections and the tank are non-pressurized.
In connection with environmentally critical products, carefully decontaminate the wetted parts of
the flange system after dismantling.