14
BM 70M-EEx/ BM 70Mi-EEx
After any maintenance work has been carried out, be sure to regrease the flameproof cover
thread of the signal converter including cover gaskets with a grease suitable for stainless steel
threads (e.g. Copper-Anticorrosion paste).
Within the scope of checks required to be carried out in hazardous areas to maintain systems in
proper working order, the following visual inspections should be carried out at regular intervals:
•
Inspection of the housing, cable entries and incoming cables for signs of corrosion and
damage.
•
Inspection of the tank connections for leakages.
8.2 Flange
Systems
The flange systems do not require any maintenance under normal operating conditions and when
used for the intended purpose. Depending on the application, however, in unfavourable operating
conditions the measuring function may be impaired by contamination of the antenna system. The
antenna should then be cleaned as described in the Installation and Operating Instructions for the
non-hazardous-duty versions. Cleaning requires that the flange system be dismantled. Such
dismantling work will need to be coordinated with field conditions (e.g. check for presence of a
flammable liquid and/or potentially explosive atmosphere in or at the tank, pressurized tank) and is
the responsibility of the operator.
9 Dismantling
9.1
Replacement of Signal Converter
The modular design of the BM 70 M-EEx level gauges allows replacement of the converter to be
carried out by undoing bolts (M) as shown in the diagram below. The flange system need not be
removed from the tank. This also applies to pressurized tanks.
Caution:
On pressurized tanks, do not remove the 4 screws (H) connecting the wave
guide window to the tank mounting flange.
DANGER TO LIFE!
Before detaching the interconnecting cables of the device, 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) and equipotential bonding conductors (PA).
Should it prove necessary to open the Flameproof Enclosure of the electronics compartment in
the presence of an explosive atmosphere, first make sure that the device is disconnected from
supply. Before opening the Flameproof Enclosure, be absolutely sure to allow the waiting time,
specified on the converter nameplate (27 minutes), to elapse first.
Summary of Contents for BM 70 M Series
Page 75: ...BM 70 M 75 10 Certificates and approvals 10 1 Declaration of Conformity...
Page 83: ...BM 70 M 83 Annex C Spare parts...
Page 84: ...84 BM 70 M...
Page 85: ...BM 70 M 85...
Page 102: ...16 BM 70M EEx BM 70Mi EEx 11 Approvals...
Page 103: ...BM 70M EEx BM 70Mi EEx 17...
Page 104: ...18 BM 70M EEx BM 70Mi EEx...
Page 105: ...BM 70M EEx BM 70Mi EEx 19...
Page 106: ...20 BM 70M EEx BM 70Mi EEx...
Page 107: ...BM 70M EEx BM 70Mi EEx 21...
Page 108: ...22 BM 70M EEx BM 70Mi EEx...