Advanced Pump Control for a Wastewater System

Pump control was crucial for improving the site’s wastewater management. Initially, the site had two tanks connected in series, each equipped with two pumps at their outlets. Tank one had two parallel pumps pumping wastewater to the second tank. The second tank mirrored this layout to pump the wastewater to the public utility system. The tanks were over 150 meters apart with a silo blocking the line of sight, complicating communication and control.

Client requirements

Meeting the client’s requirements for the pump control system involves several key elements to ensure efficient and reliable operation. First, the system will include one pump panel for each pair of pumps. This setup provides centralized control and monitoring for the paired units. To enhance reliability and prolong the lifespan of the pumps, each pair will operate in a duty standby configuration with an automated switchover mechanism that activates every five running hours. This ensures that each pump shares the workload and reduces downtime. The system will also incorporate mechanisms to start and stop the pumps based on the active water level, allowing for responsive and efficient water management.

Variable speed control will enable precise adjustments to pump operation based on real-time demands. For ease of use and monitoring, visualization and setpoint control will be centralized at one pump panel, offering operators a convenient interface for system management. Finally, the entire installation will be designed with a minimal footprint in mind, ensuring that the system is space-efficient and suitable for a variety of installation environments

We successfully supplied and installed a pump control and tank monitoring system for the two tanks, establishing reliable communication despite the distance and obstacles. The system ensured automated, safe operation with minimal human intervention.

The solution

Two panels were installed to achieve these objectives. One panel had an S7-1200 PLC and KTP400 Basic for the user interface. We deployed a Phoenix Contact Trusted Wireless 868Mhz Master module for wireless communication. Furthermore, linked the wireless module to the PLC using the RS485 protocol. We connected two Danfoss FC360 drives to the PLC via Profinet for pump control. For Panel 2, we installed two Danfoss drives and added Trusted Wireless Slave modules equipped with digital inputs, outputs, and analog input cards. Additionally, we installed ultrasonic sensors and float switches on each tank, to monitor and control tank levels.

The end Result

This project achieved significant milestones, including variable speed control and configuring pumps to operate in duty and standby modes, ensuring efficient and automatic pump control. Seamless wireless communication between the tanks was enabled, overcoming physical obstacles and distance. The reliable and automated system reduced the need for manual intervention, increasing operational efficiency. This project also demonstrated our capability to deliver complex control solutions, enhancing our portfolio and expertise in pump control systems.