Quanzhou Ausenist Technology Co., Ltd How to Choose a Constant Pressure Water Pump VFD for Industrial Systems
A constant pressure water pump VFD automatically adjusts motor speed according to real-time water demand. In factories, buildings, irrigation systems and booster stations, the right drive can stabilize pressure and protect the pump system.
However, industrial buyers should not select a water pump inverter based only on motor power. Input voltage, output phase, motor current, pressure sensor type, control method and the number of pumps must all be considered.
This guide explains the main selection criteria and introduces the Ausenist YS620 smart water pump drive as a practical solution for single-pump and multi-pump water supply systems.
What Is a Constant Pressure Water Pump VFD?
A constant pressure water pump VFD combines variable-frequency motor control with pressure feedback.
A pressure sensor continuously measures pipeline pressure. The drive's built-in PID controller compares the measured pressure with the target value and automatically changes pump speed.
When water consumption increases, the drive raises the motor frequency to maintain pressure. When demand falls, it reduces the frequency. If there is no water demand, the pump can enter sleep mode and restart when pressure drops below the configured value.
Typical applications include industrial process water, factory pressure boosting, building booster systems, agricultural irrigation, water treatment and multi-pump stations.
1. Match the Input Voltage and Motor Voltage
Voltage compatibility is the first selection step. The Ausenist YS620 series includes the following configurations:
| Power supply | VFD output | Available motor power |
|---|---|---|
| Single-phase 220V input | Three-phase 220V output | 0.75kW, 1.5kW and 2.2kW |
| Three-phase 380V input | Three-phase 380V output | 0.75kW to 7.5kW |
The specified input-voltage tolerance is ±15%, and the supported input frequency is 50/60Hz with ±5% fluctuation.
A single-phase 220V input model can therefore be useful when a facility has only a single-phase supply but needs to operate a compatible three-phase 220V water pump.
Before ordering, confirm:
- Available power supply
- Motor rated voltage
- Motor rated current
- Motor power in kW or HP
- Input and output phase requirements
- Local grid frequency
Motor current is especially important. Two motors with the same nominal kW rating can have different rated currents and load characteristics.
2. Confirm the Pressure Sensor Signal
A constant pressure pump controller depends on accurate feedback from the pipeline. The YS620 supports several analog input signals, including:
- 0–10V remote pressure gauge
- 4–20mA pressure transducer
- 0–5V analog input
For industrial installations, 4–20mA pressure transmitters are widely used because the signal is suitable for longer cable distances and is easier to monitor for abnormal conditions.
The sensor range should match the actual working pressure. For example, a 10-bar sensor may not provide the best control resolution for a system that normally operates at only 2 bar.
When requesting a quotation, tell the supplier the sensor signal and pressure range. If the sensor has not yet been selected, provide the required operating pressure so that a compatible option can be recommended.
3. Evaluate the Multi-Pump Control Architecture
For installations with variable and high water demand, one pump may not be sufficient. A multi-pump system starts or stops additional pumps according to pipeline pressure and demand.
The YS620 uses RS485 communication for coordinated multi-pump control. One drive acts as the master and can communicate with up to four auxiliary drives. Each pump is normally equipped with its own drive; the master coordinates the complete system rather than directly powering several motors from one VFD output.
Important multi-pump functions include:
- Automatic addition and removal of pumps
- Real-time communication between master and auxiliary drives
- Configurable pump rotation
- Automatic bypass of an auxiliary drive that has failed
- Master and standby-master configurations
- Synchronous or master-and-auxiliary control modes
In a standby-master system, a second drive can take over system control if the primary master fails. This is valuable for factories, buildings and other installations where an interruption in water supply would affect production or operations.
The pumps can also operate alternately. Balancing operating hours helps prevent one pump from accumulating excessive wear while the others remain underused.
4. Check the Essential Pump Protection Functions
A pump VFD should do more than regulate speed. It should also protect the pump and pipeline.
Water Shortage Protection
If detected pressure remains below the configured water-shortage level, the system can stop automatically. It can attempt a specified number of delayed restarts and resume normal operation if pressure recovers. This helps reduce the risk of a pump running without sufficient inlet water.
High-Pressure Protection
If pipeline pressure exceeds the configured limit, the drive can stop the pump automatically. This helps protect pipes, valves and connected equipment from excessive pressure.
Low-Pressure Monitoring
Low-pressure monitoring can help identify insufficient inlet water, pipe leakage, incorrect pump rotation or a pump that cannot reach the required operating point.
Electrical and Motor Protection
The drive also provides configurable protection for conditions such as overload, input or output phase loss, low voltage and other drive or motor faults.
For procurement projects, ask the supplier to confirm which protection parameters will be configured before shipment and which settings must be adjusted during commissioning.
5. Consider Motor Control and Operating Range
The YS620 uses V/F control and provides an output-frequency range of 0–200Hz. Its specified overload capability is 150% of rated current for 60 seconds and 180% for one second.
The drive must still be correctly matched to the motor, pump curve and normal operating point. Higher frequency does not automatically mean the system can safely produce more flow; motor load, pressure rating and mechanical limits must be checked.
For an accurate model recommendation, provide:
- Pump type and model
- Motor nameplate photograph
- Rated voltage and current
- Rated power and frequency
- Required flow rate
- Required pressure or head
- Number of pumps
- Intended operating schedule
Why Consider the Ausenist YS620?
The YS620 is designed specifically for water pump control rather than as a general-purpose industrial inverter. Its main advantages include:
- Built-in PID constant pressure control
- Single-pump and multi-pump operation
- RS485 communication between pump drives
- Master and standby-master control options
- Support for common pressure sensor signals
- Water-shortage and high-pressure protection
- Automatic pump rotation
- Automatic energy-saving operation under light load
- 220V and 380V model options
- Power ratings from 0.75kW to 7.5kW
It can be considered by pump manufacturers, system integrators, distributors and industrial buyers looking for a dedicated water pump VFD solution.
OEM and Customization Support
Ausenist supports OEM and ODM cooperation for pump manufacturers, distributors and system integrators. Depending on the project, customization can cover product branding, labels, packaging, operating parameters, voltage requirements and pump-system matching. Buyers should submit their target market, technical requirements, expected quantity and required certifications for factory evaluation.
Information Required for a Factory Quotation
To receive the correct model and an accurate quotation, send the following information:
- Country and destination
- Required quantity
- Input power supply
- Motor voltage, current and power
- Pump type
- Number of pumps in the system
- Required pipeline pressure
- Pressure sensor signal and range
- Single-pump or multi-pump control requirement
- OEM branding, packaging or customization requirements
- Required certificates or local market standards
Providing a motor nameplate photograph and a simple system diagram can significantly reduce model-selection errors.
Frequently Asked Questions
Can one YS620 control several pumps?
One YS620 can act as the system master and coordinate up to four auxiliary drives through RS485 communication. Each pump is normally connected to its own appropriately sized drive.
Can the YS620 use a 4–20mA pressure transmitter?
Yes. The YS620 supports a 4–20mA pressure transducer as well as other analog feedback options.
Can single-phase 220V power operate a three-phase pump?
Selected YS620 models accept single-phase 220V input and provide three-phase 220V output for compatible motors from 0.75kW to 2.2kW. The motor must be rated for the output voltage.
What is the maximum YS620 motor power?
The documented YS620 range reaches 2.2kW for single-phase 220V input models and 7.5kW for three-phase 380V models.
Is the YS620 suitable for OEM pump packages?
Yes. Pump manufacturers and system integrators can request model matching, volume quotations and OEM customization according to their motor and market requirements.
Request a Model Recommendation
Choosing the correct constant pressure water pump VFD starts with accurate system information.
Send Ausenist your motor nameplate, input voltage, pump quantity, target pressure, sensor specification and required order quantity. Our team can recommend a suitable YS620 model and prepare a quotation for your OEM, distribution or industrial water supply project.