Siemens 6SE6440-2AD37-5FA1 MICROMASTER 440 Frequency Converter Unit

Module Feature

6SE6440-2AD37-5FA1 is Siemens MICROMASTER 440 high performance general-purpose inverter, with built-in Class A EMC input filter, 3AC 380–480V input. Constant torque rating 75kW, overload capability 150% for 60s, 200% for 3s; square-law fan/pump duty reaches 90kW. It supports V/F control and sensorless vector control, maximum output frequency 650Hz. Standard RS485 Modbus communication interface, optional Profibus communication card. It integrates dynamic brake chopper terminal for external brake resistor connection. Cooling method is internal forced fan cooling, IP20 protection. Widely used for water pumps, centrifugal fans, conveyors, mixers and other general industrial motor speed control.

Working principle

Three-phase mains power is rectified to DC, then the IGBT inverter bridge converts DC into adjustable frequency and adjustable voltage three-phase AC to drive asynchronous motor. The control core executes V/F or vector algorithm according to setpoint from panel or communication. When motor decelerates, regenerative energy is absorbed by external brake resistor through the built-in chopper circuit. The drive feeds back current, speed and fault signals to the host PLC.

Onboard components

Three-phase rectifier module, IGBT power stage, built-in Class A EMC filter, current sampling circuit, brake chopper circuit, main control DSP board, RS485 communication circuit, cooling fan, power and control terminal block.

LED indicators

Front panel status LEDs for power, run, fault; parameter and alarm codes can be displayed on optional BOP/AOP keypad.

Hardware self‑diagnosis

Power-on self-test detects input phase loss, DC bus overvoltage/undervoltage, output overcurrent, module overtemperature, fan stall and communication failure. Fault codes and runtime records are stored inside the drive.

Programming software

Siemens STARTER software for parameter setting, motor identification, curve monitoring and firmware upgrade; local BOP/AOP panel for on-site adjustment.

Electrical & Process Parameters

Model:6SE6440-2AD37-5FA1 Brand:Siemens Series:MICROMASTER 440 Device type:Three-phase Frequency Inverter CT rating:75kW VT rating:90kW Input voltage:3AC 380~480V Output frequency:0~650Hz Communication:RS485 Modbus, optional Profibus EMC:Built-in Class A input filter Cooling:Forced air cooling Protection:IP20 Function:Variable speed regulation for asynchronous AC motors

Mechanical & Structure

Mounting:Cabinet backplane mounting Dimension:H1150mm * W350mm * D320mm Protection class:IP20 Housing:Metal chassis

Environmental

Operating temperature:-10℃ ~ +50℃ Storage temperature:-40℃ ~ +85℃ Ambient humidity:5~95% non‑condensing Certification:CE compliant Status:Siemens original MM440 spare drive

Installation

Install in ventilated control cabinet and reserve heat dissipation clearance. Wire three-phase input, motor output and brake resistor cables. Connect RS485 communication wiring if remote control is required. Perform motor data identification and ramp setting via STARTER or BOP panel. Test emergency stop and overload protection before commissioning. Keep fan and air filter clean regularly.

Interface

L1/L2/L3 power input terminals, U/V/W motor output terminals, brake resistor terminals, RS485 communication terminals, analog/digital I/O terminals.

Diagnostic

Overcurrent fault: Motor insulation damage, cable short-circuit or mechanical jam. DC bus overvoltage: Deceleration time too short, brake resistor missing or damaged. Over-temperature alarm: Fan failure, blocked air inlet or continuous heavy-duty operation. Communication loss: RS485 wiring error, wrong station address or bus termination issue.

Product BriefSiemens 6SE6440-2AD37-5FA1 MICROMASTER 440 inverter, 75kW constant torque /90kW variable torque, 380–480V, built-in Class A EMC filter, vector control, used for pump, fan and general automation motor speed control.