Automation Project Plan for Sewage Treatment Plant

In the automation project of a sewage treatment plant, Schneider 24 V/10 A switching power supply ABLS1A24100 is preferred to provide stable power supply for PLC and sensor modules. Its wide input range of 100–240 VAC and built-in overload and short-circuit protection ensure continuous system operation.

The key PLC is recommended to use Siemens SIMATIC S7‑1500 series controllers. Its modular design and future scalability enable it to handle the complex control requirements of large-scale water treatment processes.

For PLC I/O, Beckhoff EtherCAT plug-in I/O modules can be selected. With IP67 protection and a compact design, they support direct on-site installation, simplifying wiring and improving reliability.

The flow meter is selected as the Endress+Hauser Proline Promag W 400 electromagnetic flow meter, which has high measurement accuracy, no moving parts, and can adapt to solid-containing fluids, suitable for various flow measurement conditions.

For water level monitoring, the Pepperl+Fuchs LUC‑M40 ultrasonic level sensor is recommended. With a range of up to 10 m, its non-contact measurement reduces maintenance costs and supports continuous online monitoring of liquids and bulk solids.

For chemical dosing equipment, Grundfos digital chemical dosing pumps are selected. They communicate with the PLC system via 4–20 mA or Modbus RTU, achieving precise dose control and remote diagnostics.

The key human-machine interface can use Schneider Magelis series HMIs, which provide high-resolution touchscreens and intuitive software, facilitating on-site monitoring and process parameter adjustment.

System power redundancy is achieved by Siemens SITOP DC UPS modules, which can maintain 24 V critical circuit power supply for several hours during power outages, ensuring the safe shutdown or continuous operation of critical pumps, valves, and control logic.

In the main distribution cabinet, Phoenix Contact electronic miniature circuit breakers can be used to provide overload and short-circuit protection. They feature intelligent diagnostic functions to ensure the safe operation of the control cabinet.

In addition, to meet plant safety regulations, Banner Type 4 safety light curtains are recommended to provide personnel protection for gates and maintenance entrances.