Every water pump has one VFD, which is connected to one another through CAN communication interfaces to accomplish the controlling of constant pressure water supply and alternative operation of water pumps.
Working Principle After starting the system, one VFD drives one water pump to run. If the water is supplied in accordance with required amount, (i.e. feedback pressure is equal to the set pressure), then other water pumps retain in standby mode. At the same time, operator can set the alternation time for VFDs, enabling the VFDs to be operated alternatively. When the required water is increased, the second water pump will be activated by another VFD. In the same manner, the third, fourth up to fifth pump will be operated until the water demand is met. Five VFDs can be connected and operated at the same time. When the need of water amount is decreased, the pumps gradually enter sleep mode and stay in standby mode. And all pumps start sleep mode when water supply is no longer required. In this multi-pump system, if any VFD failure occurs, it will be replaced by another VFD to ensure smooth operation. ApplicationsAll pumps from this system adopt soft starting function for system protection, providing high precision of constant pressure. The system is suitable for various applications, such as water supplying for high-end residential areas, commercial fields, agricultural irrigation, industrial production, etc.