A variable-frequency constant-pressure water supply system adjusts pump speed on demand via a pressure sensor and drive, keeping pipeline pressure steady. Compared with conventional fixed-speed or throttled water supply, it delivers the following benefits. Suitable drives are the XFC550 vector-control VFD (380 V, 1.5–450 kW) (see the full low-voltage VFD range).
1. Energy Saving
The system matches pump speed to actual water demand and can save 20%–40% of electricity, enabling green operation.
2. Compact Footprint, Low Investment, High Efficiency
Smaller footprint, lower capital outlay and higher operating efficiency than traditional water-supply schemes.
3. Flexible Configuration, High Automation
Flexible configuration, high automation, complete functions, reliable and adaptable operation.
4. Smooth Operation — Soft Start and Soft Stop, No Water Hammer
Because pumps start and stop softly rather than abruptly, the system eliminates the water-hammer effect. Average torque and wear on the motor shaft are reduced, maintenance work and cost are cut, and pump service life is greatly extended.
5. No Secondary Pollution
Variable-frequency constant-pressure supply draws water directly from the source, removing the secondary contamination caused by older water-supply methods.
6. Unmanned Operation
Communication-based control enables unattended pump stations, saving both labor and material resources.
7. Networked Monitoring
Real-time monitoring of each station: motor voltage, current, operating frequency, pipeline pressure and flow.
8. Flexible Control Modes
Stage-wise water supply, timed water supply, and manual selection of operating mode.
9. Comprehensive Self-Protection
Complete self-protection: if one pump faults, the system actively sends an alarm to the host/upper computer.


