Connection and operation manual
Technical changes reserved
0141 0316-152 13.05.2016
Level controller for conducting liquids
24 V OEM-version without housing
5.4.1
Pin configuration of input socket (RJ12)
Pin
Function
Colour (6 core cable ) Description
1
UB
White
15 V
2
E 4
Brown
Level 4 (E4), highest
3
E 3
Green
Level 3 (E3)
4
E 2
Yellow
Level 2 (E2)
5
E 1
Grey
Level 1 (E1), lowest
6
COM
Pink
Reference electrode
Top view of contacts on the plug!
5.6
Construction of sensor
The sensor can be constructed in various ways:
•
In plastic containers, the electrodes can be fitted in pairs on the container wall. Each pair always consists of a reference electrode
and a sensing electrode, which are placed at a distance of approx. 5-15 cm from each other. For liquids of high conductivity, just
one electrode at the bottom of the container is also good enough. The reference electrodes are connected together to the terminal
COM. Due to contamination deposits on the container walls with time, such constructions are probably not maintenance free. The
wall area between the electrodes should be periodically cleaned.
•
Electrodes of stainless steel rods, hanged from top into the medium, are ideally suited for this purpose. The reference electrode is in
the middle of the 4 diagonally arranged sensing electrodes which are placed in a span of approx. 1-5 cm. The spacing should be wide
enough so that no drop of liquid sticks back to the rods when the level falls down. These electrodes are practically maintenance free.
•
Cable probes are very simple to manufacture. For this purpose, multi-core silicon cable can be stripped at the end and joined to stain
-
less steel balls which act as weight and also contact surface. The individual weights are lowered in the container up to the desired
switching point and then the cable is tied up. For reference electrode, a bare stainless steel rope with weight can be used, which goes
up to the bottom of the container. Cable sensing elements are also very reliable and practically maintenance free.
•
For applications in condensate tubs and for low liquid levels, the sensing system can be constructed as a PCB which is mounted on
the tank wall. Such sensing elements should also be periodically cleaned if the medium is polluted.
B+B Thermo-Technik GmbH | Heinrich-Hertz-Straße 4 | D-78166 Donaueschingen
Fon +49 771 83160 | Fax +49 771 8316-50 | [email protected] | bb-sensors.com
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