KROHNE BM 26 A EN - Manual (Page 26)

26 Installation and Operating Instructions BM 26 A
3 Limit switches / contacts
3.1 General notes
To signal specific liquid levels, the BM 26 A bypass level indicator can be equipped with 13 different
types of limit switch that are clamped to the measuring tube and are adjustable over the whole
measuring range. They are actuated by a magnet incorporated into the float. The operating
conditions define which limit switches may be used. Refer to section 7.3 for detailed technical data
on each type of limit switch.
The limit switches are delivered separate from the BM 26 A gauge and have to be mounted on site.
See sections 3.5 to 3.6 for installation instructions.
3.2 Designation code for defining limit switch versions
Housing
protection
Cut-out
power Housing
material NAMUR
conformity Process
temperature
applications
STD (Without) LC (Low power
cut-out) PC (Polycarbonate /
Standard) NN (Non-
NAMUR) BT (Low
temperature)
EXI (EEx ia)
EXD (EEx d)
HC (High power
cut-out) AL (Aluminium) NO (NAMUR) HT (High
temperature)
3.3 Limit switch options for the BM 26 A (non-Ex)
Designation Housing
protection
Housing
material Power cut-out Process temperature Ambient
temperature
/ °C Ambient
temperature
/ °F
MS20/STD/L
C/PC/NN/BT Without PC 30VA
0.5A
230V AC <250°C <480°F -20...+120 -5...+245
MS15/STD/L
C/PC/NO/BT Without PC NAMUR <250°C <480°F -20...+120 -5...+245
MS15/STD/L
C/AL/NN/HT Without ALU 20VA
1.5A
250V AC
<300°C <570°F -20...+120 -5...+245
MS15/STD/L
C/AL/NO/HT Without ALU NAMUR <300°C <570°F -20...+120 -5...+245
MS15/STD/H
C/PC/NN/BT Without PC Max.: 100VA
Min.: 3VA
1.5 A
250V AC
<250°C <480°F -20...+120 -5...+245
MS15/STD/H
C/AL/NN/HT Without ALU Max.: 100VA
Min.: 3VA
1.5A
250V AC
<300°C <570°F -20...+120 -5...+245