Instructions

MANUALS
Technical changes reserved
0141 0316-112 05.2014
Level controller for conducting liquids
WLS-GEH230V
2.2 Operating sequence diagram
Initial condition : The reservoir is rst empty. The electrode E1 is not in water contact. Relay 1 is in closed position (because of this e.g.
the inlet valve is open). The water level rises in the reservoir. Water contact with the lower Electrode E1 (1) does not change the relay
status and only when Electrode E2 comes into water contact (2), Relay 1 switches OFF (as an effect e.g. the inlet valve closes).
Upper level: If the level in the reservoir continues to rise further and reaches Electrode E3, Relay 2 still remains in off state. After the
water level reaches Electrode E4 (4), Relay 2 is switched ON (and with that e.g. the outow pump). When the level falls and Electrode
E4 is released free (5), the relay remains closed until Electrode E3 is released free. (6). This means that between the upper switching
ON point E4 and the lower switching OFF point E3, there is a hysteresis gap.
Lower level: If the level continues to fall, the Electrode E2 becomes free (7). In the reducing level direction, Relay 1 is kept in off state,
till Electrode E1 is also out of water contact (8). Only then Relay 1 closes. If again the water level is in rising direction, Relay 1 remains
closed even after water contact with Electrode E1 (9). Only if Electrode E2 again comes under water contact, Relay 1 is switched OFF
(10). Hence, the lower level also has a provision of hysteresis margin.
The referred appliances “Inlet valve“ or “Pump“ are taken only as examples for illustration of the working principle. What appliances are
used nally depends on the application. The switching behaviour of both the relays can be reversed through two jumper connections.
The two relay circuits work as level regulators and are independent of each other. Hence, it is not necessary to use both the circuits, the
device is also suitable for controlling only one level. For this purpose, only two sensing electrodes and a reference electrode are required.
In such a case, the second channel (relay and electrode inputs) is not used.
2.3 Model description
There are two relays with NO/NC contacts for control of the appliances (valve/pump). The NO contact can be loaded up to 230 V / 5 A
AC and is provided with a varistor for surge suppression. The NC contact can be loaded up to 230 V / 2 A .
The model in housing is provided with a 230 V AC power supply and a control unit with LEDs for level indication and also pushbuttons
for manual switching of the relays.
Typical areas of application: Water harvesting/monitoring in rain water cisterns, monitoring of condensate tubs and compressor pressure
chamber, boiler, fountains and wells, cattle watering places, control of pumps.
B+B Thermo-Technik GmbH | Heinrich-Hertz-Straße 4 | D-78166 Donaueschingen
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