Afriso EURO-INDEX OWWG3 Series, Operating Instructions Manual

Page: 51 / 156

Product description
ÖWWG 3 11
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 collecting areas of oil
storage rooms implies the danger 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 waste
water 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, any oil that may result from a leak and floats
on the water is not detected by ELT 8 since oil is not conductive. The
PTC thermistor probe of ÖWWG 3 is submerged in the oil on the
water. ÖWWG 3 triggers visual and audible alarms and keeps the
waste water pump from being switched on.