Monitoring and Alarm

Large scale monitoring and alarming systems (SCADA).

Underground mining system:

A wide area monitoring system in an underground mine covering 27 km. Monitoring gas levels, fire sensors, blowers, alarm buttons and indicators, water reservoirs, safety doors, emergency shelters, etc., a total of 2'000 analogue and discrete I/O points, some serial.

The system was interconnected by a dual RS-485 redundant serial ring. A number of breaks were allowed, without affecting the performance. Each break was shown with approximate location and timestamp. The response time of the system is 3 seconds.

Information is displayed at the safety control centre and a couple of secondary displays around the area.

 

Fresh water pump stations:

Fresh water collection for suburb of 500'000 people. A system of 27 underground pumps collecting water in 3 reservoirs. Pumping according to schedule, water level or emergency situations (i.e. fire fighting).

Each pumping station is equipped with a local controller. All controllers interconnected by optical fibre to a redundant central control.

Bacterial leaching control:

For copper-sulphide treatment, a new bacterial leaching process was implemented. The activity of the bacteria is controlled by the concentration of sulphuric acid sprayed on top. The reaction is measured by temperature sensors. This system is installed at an altitude of 5'000 meters above sea level.

A total of 1'200 analogue temperature sensors distributed over an area of 60'000 m² monitor the bacterial activity. A number of local controllers (PLCs) regulate the concentration of the acid solution, to ensure optimal production level.

Electrical substation fault treatment:

Earth fault or phase-to-phase fault cause sections or areas of suburbs to disconnect. To counter-react the sudden voltage raise, a certain number of capacitor banks at the substation are disconnected until the supply regulation is stable again (after some seconds).

The exact fault pattern is verified in 400 ms to react with the appropriate number of capacitor banks and to filter spurious signals like lightning. The whole fault process is logged and the voltage variation graphically displayed with the resolution of one cycle.

contact: info@NovaTerra.ch