FST-650S Water Pump VFD Dedicated Pump Inverter Constant Pressure Control 18.5kW

The Anyhz FST-650S is a dedicated water pump VFD engineered specifically for pump applications from 18.5kW to 110kW. This all-in-one pump inverter integrates variable frequency drive, PID controller, and protection systems in a rugged IP54 cabinet—delivering constant pressure water supply with minimal installation and maintenance.

Designed for municipal water supply, building services, irrigation, and industrial pumping, the FST-650S features built-in dual PID controllers for pressure/flow control, intelligent sleep function for energy savings during low demand, and wide voltage operation (320V-450V) for unstable grid conditions. With 20-40% energy savings compared to throttle valve control, the FST-650S pays for itself within 1-2 years while improving system reliability.

• All-in-One Design: VFD + PID + protection in IP54 cabinet, no external controllers needed
• Built-in Dual PID: Two independent PID parameter sets for pressure and flow control, switchable via terminal or communication
• Intelligent Sleep Function: Automatic sleep/wake based on demand, reducing energy waste by 30-50% during low-flow periods
• Wide Voltage Operation: Normal operation from 320V-450V handles grid fluctuations without tripping
• Pump-Specific Protection: Dry-run protection, underload detection, pipe burst detection, and soft-fill function
• Environmental Hardening: IP54 protection, high dust resistance, and operation in hot/humid environments
• Easy Commissioning: Auto-tuning and pre-configured pump parameters minimize startup time

The FST-650S includes two independent sets of PID parameters that can be switched via digital input or serial communication. This allows seamless transition between pressure control (for constant pressure systems) and flow control (for variable demand systems), or between different operating schedules. Each PID has separate proportional, integral, and derivative gains for optimal response in different conditions.

• PID1: Primary control (e.g., discharge pressure)
• PID2: Secondary control (e.g., flow rate or tank level)
• Auto/manual mode switching
• PID output limiting and ramping

The sleep function automatically stops the pump when demand drops below a set threshold (e.g., at night), then wakes instantly when pressure drops or flow is detected. Unlike simple on/off control, the FST-650S monitors system pressure during sleep and can wake before critical low pressure occurs. This eliminates energy waste from running pumps against closed valves while ensuring immediate response to demand.

• Sleep frequency and pressure thresholds adjustable
• Wake on pressure drop or external signal
• Zero-flow detection for leak identification
• Pre-sleep pressure boost for extended sleep periods

Standard VFDs only protect the motor—the FST-650S protects the entire pump system. Dry-run protection detects loss of prime and stops the pump before damage occurs. Underload detection identifies broken shafts or coupling failures. Pipe burst detection recognizes sudden pressure drops indicating line breaks. The soft-fill function prevents water hammer when filling empty pipes.

• Dry-run protection: Current and power monitoring
• Underload detection: Broken shaft/coupling alarm
• Pipe burst detection: Rapid pressure drop shutdown
• Soft-fill: Controlled acceleration prevents water hammer

The FST-650S supports multi-pump systems with automatic rotation and cascade control. Connect up to 4 pumps (1 variable speed + 3 fixed speed) for efficient staging. The built-in logic automatically starts/stages fixed-speed pumps as demand increases, while the variable-speed pump handles trim control. Automatic rotation ensures equal runtime across all pumps, extending system life.

• 1 variable speed + 3 fixed speed pump control
• Automatic pump sequencing and staging
• Runtime balancing and automatic rotation
• Backup pump auto-start on failure

Designed for challenging electrical and environmental conditions, the FST-650S operates reliably from 320V to 450V input —handling voltage sags and swells that would trip standard drives. The IP54 cabinet protects against dust and water spray, while the high-temperature design ensures operation in outdoor installations up to 45°C. No additional enclosures or cooling systems needed.

• 320V-450V operation: Handles ±15% grid fluctuations
• IP54 protection: Dust and water spray resistant
• High ambient temperature: 45°C without derating
• Instant stop function: Emergency shutdown capability

Integrate with SCADA systems via RS-485 Modbus RTU for centralized monitoring and control. Remote access to all parameters, real-time pressure/flow data, and alarm history enables predictive maintenance and reduces site visits. The LED display shows frequency, voltage, current, and pressure feedback for local monitoring.

• RS-485 Modbus RTU standard
• Remote parameter access and adjustment
• Real-time pressure, flow, and power monitoring
• Alarm history and fault logging

• Input Voltage: 3-phase 380V (-20% to +15%), 47-63Hz
• Output Voltage: 0 to rated input voltage
• Output Frequency: 0-500Hz (pump applications typically 0-60Hz)
• Efficiency: ≥97%
• Control Methods: Sensorless vector control (SVC), V/F control
• Starting Torque: 0.5Hz/180% (SVC), 1Hz/180% (V/F)
• Speed Regulation Range: 1:100 (SVC)
• Speed Control Accuracy: ±0.5% maximum speed (SVC)
• Overload Capacity: G type: 150% for 60s, 180% for 10s; P type: 120% for 60s, 150% for 10s
• Carrier Frequency: 1.0-15.0kHz (auto-adjust based on temperature)

• Protection Class: IP54 (dust and water spray resistant)
• Operating Temperature: -10°C to +45°C (derate above 45°C)
• Humidity: <95% RH, no condensation
• Altitude: ≤1000m (derate 1% per 100m above)
• Cooling: Forced air cooling
• Cabinet: Floor-standing, RAL 7035 standard

• Standard: RS-485 with Modbus RTU
• Digital Inputs: 7 switch inputs (including 1 high-speed pulse)
• Analog Inputs: 2 channels (0-10V, 4-20mA, -10V to +10V)
• Digital Outputs: 1 open collector + 2 relay outputs
• Analog Outputs: 2 channels (0-20mA or 0-10V)
• Display: LED showing frequency, voltage, current, pressure