Watchdog Guards Against Tank Overfill

Afriso’s (Germany) NB 220 QSA Watchdog overfill alarm system, consisting of the type 76...(A, C, E, M, N) level sensor and the NB 220 QSA transducer which serves as a level controller, is designed to prevent overfilling of tanks with water-polluting liquids. The overfill alarm system may be used with stationary tanks for storing inflammable and non-inflammable water-polluting liquids (such as fuel oil EL, biodiesel, diesel, gear oils, hydraulic oils and vegetable oils). The level sensors may be used for fluid temperatures between –25 °C to +50 °C (version H up to +80 °C).

Operational safety is high since the unit continuously monitors the characteristic of the level sensor and checks for short circuits and cable breaks between the level sensor and the level controller. If a signal is generated, the filling process is interrupted and the unit triggers audible and visual alarms.

Control lamps as well as a test and a reset button at the front ensure easy operation. The NB 220 QSA transducer is supplied with AC 230 V; 2 voltage-free changeover contacts (1 can be reset) are available for alarm and control devices. The overfill alarm system is optionally available as NB 220 QSA-AC 24 V for supply with AC 24 V or as NB 220 QSA-DC 24 V for 24 V direct voltage. The additional device type 907 Z can be connected to the transducer as an additional control unit to enable connection to a tank lorry with a filling system.