Water Treatment

Operating condition keywords for the water industry arescattered sites, humid environments, frequent lightning strikes, unattended operation. A wastewater treatment plant often covers multiple scattered sites such as lifting pump stations, screens, aeration, secondary settling, chemical dosing, sludge dewatering and effluent monitoring, with overhead lines and outdoor electrical cabinets exposed to rain and lightning over the long term.

Common challenges:During the thunderstorm season, surges intrude along power and signal lines, causing batch damage to transmitters, PLC modules and communication equipment; signals from submersible pumps, ultrasonic level meters and float switches are susceptible to interference in humid environments; signals from online analysers such as pH, residual chlorine and turbidity need to be isolated from the control system; scattered sites lead to high manual inspection costs, creating an urgent need for remote monitoring.

Our solution:Surge protectors providing graded protection for control power, 4–20 mA and communication lines are the most cost-effective first step of retrofit; signal isolators ensure stable signals between analysers and the control system; submersible level meters and level switches are isolated and converted before entering the acquisition system; temperature transmitters are used for water temperature monitoring in aeration and biochemical tanks; H-System remote I/O can be installed close to the pump station site and, combined with 4G transmission, enables minimally attended operation.

After the retrofitthe lightning damage rate drops significantly and inspection frequency is reduced, providing greater assurance that effluent quality stably meets standards.

• Level monitoring for lifting pump stations, screen rooms and equalisation tanks
• Dissolved oxygen, water temperature and blower interlock loops for aeration tanks
• Flow, level and metering pump status of dosing systems
• Signal isolation for influent/effluent online analysers and in-station communication protection