Updated: May 4, 2022
Morton Electric understands the needs of water processing facilities and the importance of being able to provide fresh clean drinking water reliably to humanity. Our combined background in the automation industry and renewable energy allows us to provide a PLC controlled architecture with variable frequency drives (VFD’s) that will allow water processing plants to operate at higher reliability and efficiencies. The design approach can be used in the construction of new plants, or in retrofits of older plants. Our mission is to help water treatment facilities lower their operating costs and improve their reliability with the ultimate goal of allowing the facility to operate in off-grid mode powered by solar energy and battery if necessary.
There are many features of VFD’s that allow pump motors to operate at higher efficiencies versus the old standard on/off contactor relay. When a large motor is turned on with an electro-mechanical relay, a large inrush of current is required to start the motor and create rotation. This results in large demand charges by the utility company which can sometimes be as much as the amount the facility pays for Kilowatt hours. With VFD’s, the pump motor can be started gradually or slowly with a controlled power output or current and has the benefit of reducing demand charges and also is much easier on the pump resulting in longer life for the pump. Morton’s programming architecture allows the plant operator to monitor the current levels of the VFD’s and set alarms to monitor and predict future problems with pumps such as a bearing or impeller failure. By being able to see these issues before they occur, maintenance or replacement can be scheduled in more predictable and convenient time periods.
Also, with on/off contactors, pumps are always operating at maximum speed and/or load even when water demand from the public may not be as high. When a pump operates at full speed and water flow requirements are low, the pumps sends water through a pressure relief valve which simply sends water back to the plant. This is a large waste of energy when the pump is sending large amounts of water through a pressure relief valve. With VFD’s, pumps can be operated at lower speeds which will be directly dependent on the amount of water flow or demand that is required by the public. This can be monitored by upstream pressure and flow sensors in the water distribution system and the speed of the pump can be adjusted accordingly with the goal of sending less water through the pressure relief valve when demand is low.
Other benefits of utilizing VFD’s in water plant design include the ability to power the pumps from a DC Bus which could be directly coupled to a battery energy storage system, or BESS. This would allow greater efficiency when the pumps are operating from a DC Bus coupled directly to a battery-powered by solar energy, and eventually pave the way for the plant to operate in ‘off-grid’ mode.
The basis of knowledge comes from years of experience designing and programming automated machinery for hydraulic power units specifically for Caterpillar, Inc. Our preferred platform is based upon the Rockwell Automation solutions of ControlLogix PLC’s and PowerFlex drives. Additional advantages that can be gained with our platform include enhanced fault detection, operator controllable startup sequences, full automatic or manual operation, intuitive HMI operator interfaces, fault current setpoints, and fully customizable sequences to fit individual plant characteristics.
Morton Electric is a Certified B Corporation located in Evansville, Indiana. We provide all levels of electrical support to water processing facilities from engineering to electrical maintenance and operation.
Brad D. Morton