A revamp project at a German drinking water treatment plant has confirmed PROFINET’s advantages in terms of simplified commissioning and field device handling – as well as its speed, robustness, and ability to adapt to different network topologies.
The Wehebach Dam plant produces approximately 9 million cubic meters of drinking water per year for the Greater Aachen region. The plant was built in the 1980s, and owner WAG Nordeifel mbH decided the second filtration stage needed an update.
An important feature of the project was to test the advantages of PROFINET, which WAG Nordeifel and service provider enwor had not previously used. The two companies hoped to see simpler commissioning and easy device exchange as well as high reliability and powerful diagnostics.
In summer 2017, 42 PROFINET-enabled electric valve actuators (AUMA) were installed across the seven basins that make up the plant’s second filtration stage. The actuators control the movement of valves that in turn regulate the flow of water and air into and out of the sand filters.
Simple Cat 6 cables link the six actuators of each filtration basin to a PROFINET switch in a star topology. These switches communicate with the higher-level host system. Compared to the previous system there is more space in the control cabinet, as PROFINET does not require repeaters or cable terminators. Automatic polarity exchange and crossover functions further simplify cabling.
Device configuration was straightforward. First each actuator was assigned a device name and IP address, after which the necessary parameters and function blocks were configured. Settings from the first filter were simply copied to the other six.
Fault diagnosis and device exchange have also proved easy. ‘Neighbourhood detection’ lets the system recognize which IP address and hence which actuator is assigned to each port. A replacement actuator automatically picks up the device name and IP address of its predecessor, allowing seamless handover.
Thomas Hackenbroich, Head of the Control Engineering department at enwor, is convinced of the advantages of PROFINET. During installation and commissioning, simple cabling, compact layouts and easy device configuration are key. In operation, the biggest advantages arise from efficient fault diagnosis and rapid device exchange.
The Wehebach Dam project shows clearly that older plants can be successfully upgraded to the latest technology by installing PROFINET with suitable field devices.