Afriso EURO-INDEX OWWG 3, Operating Instructions Manual

Page: 51 / 135

Product description – German –
12 ÖWWG 3
3.5 Application examples
1 Mains voltage
2 Control unit
3 Control line
4 Waste water pump
5 PTC thermistor
probe
6 Maximum level
7 Minimum level
8 Residual water
Fig. 3: Waste water pump control with automatic oil safety facility
The operation of automatic drainage pumps in collection facilities of
oil tanks implies the hazard of oil reaching the sewage system in
case of a tank leak. The combination of ÖWWG 3 and ELT 8 with
probes selected for this purpose prevents oil damage. The
wastewater pump is controlled by ELT 8 and a 3-rod probe and
pumps the water from the soakaway. The pump is switched on when
the water has reached the maximum level and switched off when it
has fallen to the minimum level. Since ELT 8 operates on the basis
of the conductivity principle, non-conductive oil that may result from a
leak and floats on the water is not detected by ELT 8. The PTC ther-
mistor probe of ÖWWG 3 is submerged in this oil, triggers visual and
audible alarms and keeps the wastewater pump from being switched
on.