Main Features
Digital Inverters
The DFNT series frequency converters are designed for open loop control of three-phase asynchronous motors, combining ease of use and flexibility with high control characteristics. The modulation optimization (SVPWM and DPWM) allows over-modulation and provides stability at high frequencies (2 to 3 times the rated current).

Special Functions

• Motor Interface: Includes motor auto-tuning for low-speed optimization, slip compensation, line loss restart, motor stall protection, de-rating current curve selection for self-cooling motors, and initial boost for under-load start.
• Technology and Control: Features energy-saving functions, over-modulation for voltage increase, skip frequencies with programmable bandwidth, DC current injection braking, regeneration during power interruptions, DC voltage limitation in braking mode, and inverter temperature self-monitoring.
• Set-up and Programming: Offers PC monitor software with scope function, parameters and alarms storage, RS485 serial port with Modbus protocol, diagnostic and programming keypad, and optional fieldbus programming.

Power

• Technical data includes three-phase 400 to 440V with frequency 50/60 Hz, power supply from external DC bus, IGBT power stage, PWM frequency of 3 to 9 kHz, built-in soft start device, and maximum overload of 150% for 30 seconds (S1) and 200% for 30 seconds (S2).

Control and Regulation

• Features full digital regulation with high calculation performance (DSP), frequency regulation with internal torque loop, output frequency range of 0 to 1,300 Hz, programmable V/F characteristic, and independent ramps with S or linear motion profile.
• Protections include diagnostics for short-circuit, inverter over-temperature, motor over-temperature, motor overload, and voltage issues.
• Signals and references include 8 opto-isolated digital inputs, 3 analog inputs for frequency and torque references, 3 configurable digital outputs, 2 programmable analog outputs, and digital speed jog references.

Technical Data

• Mains supply voltage is three-phase 400 to 440V with line frequency of 50 to 60 Hz. The environment temperature range is 0 to 45°C with protection IP 20.
• Overload capabilities vary by size, with specific ratings for different overload percentages and durations.

Options

• Communication cards available include CAN BUS, PROFIBUS DP, and RS232/485 interface card for PC connection.
• Accessories include remote keypad, clamping circuit predisposition, clamping resistors, line inductors, EMC filters, and predisposition for analog inputs 4 to 20 mA.

Dimensions
Dimensions vary by size, with specific height, width, and depth measurements provided for each model.