KROHNE BM 26 A EN User Manual
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Installation and Operating Instructions BM 26 A
Contents
General advice on safety............................................................................................................. 4
Description: BM 26 A bypass level indicator with magnetic flaps or bar scale ..................... 4
Documentation symbols ............................................................................................................. 5
Handling ....................................................................................................................................... 5
Product liability and warranty..................................................................................................... 5
Items supplied.............................................................................................................................. 5
Standards / Approvals................................................................................................................. 6
Official approvals and certificates ............................................................................................. 7
Principal gauge components...................................................................................................... 7
1
Installation ......................................................................................................................... 8
1.1
Packing and storage ............................................................................................................. 8
1.2
BM 26 A construction details............................................................................................... 10
1.3
Mechanical installation requirements .................................................................................. 12
1.4
Mounting on the tank........................................................................................................... 13
1.5
Start-up procedure .............................................................................................................. 14
1.6
True level indication ............................................................................................................ 15
1.6.1
Level measurement using the local indicator and scale .................................................. 15
1.6.2
Floats ..................................................................................................................... 16
1.6.3
Changing the process conditions .................................................................................... 18
1.6.4
Correcting the scale position to accurately read true liquid level..................................... 20
1.6.5
Functional check of local level display (bar indicator only).............................................. 22
2
Level transducer ............................................................................................................. 23
2.1
General notes...................................................................................................................... 23
2.2
Transmitters ........................................................................................................................ 24
2.2.1
Transmitter versions for the BM 26 A.............................................................................. 24
2.2.2
Electrical connections ..................................................................................................... 24
3
Limit switches / contacts................................................................................................ 26
3.1
General notes...................................................................................................................... 26
3.2
Designation code for defining limit switch versions ............................................................. 26
3.3
Limit switch options for the BM 26 A (non-Ex)..................................................................... 26
3.4
Limit switch options for the BM 26 A (ATEX version) .......................................................... 27
3.5
How to use a limit switch ..................................................................................................... 27
3.5.1
Operating principle .......................................................................................................... 27
3.5.2
Installation ..................................................................................................................... 27
3.5.3
Overall dimensions of limit switches mounted on measuring tube .................................. 29
3.5.4
Limit switch dimensions (without bracket and clamp)...................................................... 30
3.5.5
Electrical connections ..................................................................................................... 31
3.6
Fine adjustments to the limit switch trigger point................................................................. 33
3.6.1
General notes.................................................................................................................. 33
3.6.2
Fine adjustments to the limit switch trigger point............................................................. 33
3.6.3
Switching point diagram and offset values for limit switches........................................... 34