In order to ensure the water pressure for users living in high-rise apartments in the past, water tanks were generally placed on the top floor to solve the problem. The disadvantage of this method is that the water pressure of high-level users is obtained by natural gravity, and the pressure is relatively small. At the same time, the water tank will be polluted by the environment, resulting in poor water quality. In addition, at the peak of water use, even if you live on the bottom floor, you cannot get the proper water pressure. Therefore, using frequency conversion for constant pressure water supply is an ideal solution. The frequency conversion constant pressure water supply system independently developed by our company has been widely used in factories, hotels, apartments and residential areas. Since 2001, it has been recognized by the Shinan Branch of Shanghai Water Supply Company. Our company's variable frequency and constant pressure water supply device is used as a supporting facility for residential communities.

Electric circuit of variable frequency and constant pressure water supply device

ØThe system consists of a human-machine interface (PMU), PLC, and frequency converter to form a complete automation system. PMU is used as the master switch and system information display unit, and the operation of the inverter is controlled by the PLC.
ØSet start, stop, interlock, target value display and feedback value, operation status of each motor, fault information, etc. in the PMU.
Ø Make the electrical interlock control program in the PLC, and set the target value through the analog input and output module.
Performance characteristics of variable frequency constant pressure water supply device
ØHigh efficiency and energy saving: The system can set the pressure or flow rate as required, and automatically control and adjust the running speed and number of pumps, so that the equipment runs in an efficient and energy-saving state.
ØStable water supply pressure: The system adopts closed-loop control, which can automatically adjust the system pressure according to the setting to keep the pressure constant.
ØEasy operation: adopts inverter and PMU man-machine interface, Chinese display, operation is extremely simple.
ØStable system and long service life of the motor and water pump: The system adopts frequency converter control, and the system water pump has a soft start function, which eliminates the starting impulse current and prolongs the service life of the equipment. The system water pump has an automatic timing cycle operation to prevent the water pump from rusting due to long-term use or frequent use and wear.
ØPerfect protection function: The system has protection functions such as short-circuit, over-current, over-voltage, and overload. When the system fails, it can automatically stop working and alarm output; the system has self-checking, fault judgment, fault memory, fault display, and automatic start standby
Functions such as use, overpressure and underpressure alarms, set pressure and actual pressure display.
ØSmall flow sleep function: It can be equipped with an attached small pump, so that the system will automatically turn off the main pump and turn on the small pump to save energy and reduce noise at night or under low flow conditions. The pump opening time and working mode can be set freely.
Ø Equipped with manual switch control: it can ensure the safe and continuous operation of the equipment. It can be connected to a computer through a serial port to realize direct control of the computer's network connection.
Main Specifications
1. Flow rate adjustment range: 0-50 m³/h 2. Pressure adjustment range: 0-1.6 mPa
3. Control motor capacity: 0.37-400Kw 4. Pressure adjustment accuracy: <±0.01mPa
5. Pressure stabilization time: <15s 6. Control mode: constant pressure at outlet
7. Operation mode:
□Single control □One use and one standby □Two use and one standby □Three use and one standby □Other control modes