6SE6440-2UD24-0BA1 MICROMASTER 440
The Siemens MICROMASTER 440 (MM440) is a high-performance general-purpose variable frequency drive (VFD) belonging to the MICROMASTER 4 series. The specific part number 6SE6440-2UD24-0BA1 is a 4.0 kW, 3-phase 400 V AC unit designed for precise speed and torque control of standard induction motors. It is manufactured by Siemens and represents a well-established platform widely deployed across industrial automation environments.
The 6SE6440-2UD24-0BA1 features vector control capability including sensorless flux current control (FCC) and closed-loop vector control with encoder feedback, enabling high dynamic performance. It supports multiple communication options via optional PROFIBUS, DeviceNet, or CANopen communication modules, and includes a built-in RS-485 serial interface (USS protocol). The drive provides a programmable digital I/O complement of 6 digital inputs, 3 digital outputs, 2 analog inputs, and 1 analog output, along with an integrated EMC filter and a DC link choke for improved harmonic performance. Protection features include overvoltage, undervoltage, overcurrent, overtemperature, and motor stall protection, with a degree of protection of IP20 as standard.
The MICROMASTER 440 series is used extensively in manufacturing, material handling, pumping, fan and compressor control, and process industries such as food and beverage, chemical, and automotive. The 4.0 kW rating of this unit makes it suitable for driving conveyor belts, small pumps, fans, mixers, and similar loads where variable speed control is required. Its robust feature set and flexible I/O configuration make it adaptable to both standalone and integrated PLC-controlled automation systems.
Technical Specifications
| Power Rating | 4.0 kW |
|---|---|
| Input Voltage | 380 – 480 V AC (3-phase) |
| Output Voltage | 0 – 480 V AC (3-phase) |
| Output Current (Continuous) | 10.2 A |
| Output Frequency Range | 0 – 650 Hz |
| Control Type | V/f control, Sensorless vector control (FCC), Closed-loop vector control |
| Digital Inputs | 6 programmable digital inputs |
| Digital Outputs | 3 programmable digital outputs (relay) |
| Analog Inputs | 2 (0–10 V / 0–20 mA) |
| Analog Outputs | 1 (0–20 mA) |
| Communication Interface | RS-485 (USS protocol); optional PROFIBUS DP, DeviceNet, CANopen |
| EMC Filter | Integrated Class A EMC filter |
| Protection Rating | IP20 |
| Operating Temperature | –10 °C to +50 °C |
| Storage Temperature | –40 °C to +70 °C |
| Relative Humidity | 95% non-condensing |
| Certifications | CE, UL, cUL |
| Series/Product Family | MICROMASTER 440 (MM440) |
Frequently Asked Questions
What is the power rating and supply voltage of the 6SE6440-2UD24-0BA1?
This unit is rated at 4.0 kW and requires a 3-phase 380–480 V AC supply. The continuous output current is 10.2 A.
Does the MICROMASTER 440 support closed-loop vector control?
Yes, the MM440 supports closed-loop vector control with an encoder feedback module (optional), as well as sensorless vector control (FCC) and standard V/f control modes.
What communication protocols are supported?
The drive includes a built-in RS-485 interface supporting the USS protocol. Optional communication modules allow PROFIBUS DP, DeviceNet, or CANopen connectivity.
Is an EMC filter integrated into this unit?
Yes, the 6SE6440-2UD24-0BA1 includes an integrated Class A EMC filter suitable for industrial environments.
What is the default protection rating of this drive?
The standard enclosure provides IP20 protection. For higher ingress protection, an optional IP54 cabinet or enclosure kit is required.
Troubleshooting
Drive displays fault F0001 (overcurrent) on startup or during acceleration
Check motor cable for short circuits or ground faults. Verify motor nameplate data matches drive parameter settings (P0304–P0311). Check acceleration ramp time (P1120).
Increase acceleration ramp time (P1120), verify correct motor data entry, and inspect motor and output cables for insulation faults. If fault persists, check for a seized or overloaded mechanical load.
Drive displays fault F0002 (overvoltage) during deceleration
Measure DC bus voltage during deceleration. Overvoltage typically occurs when regenerative energy from the motor cannot be dissipated quickly enough.
Increase deceleration ramp time (P1121), enable the Vdc-max controller (P1240), or connect an external braking resistor to the DC bus terminals.
Drive displays fault F0003 (undervoltage) during operation
Measure the incoming supply voltage at the drive input terminals. Check for voltage dips or supply interruptions during operation.
Verify that the supply voltage is within the 380–480 V AC range. Check supply fuses, contactors, and cable connections. Adjust the undervoltage trip threshold if supply fluctuations are within acceptable limits.
Motor runs but speed does not respond to analog reference signal
Check analog input wiring at terminals 3 and 4 (AIN1). Verify parameter P0700 (command source) and P1000 (frequency setpoint source) are configured for analog input.
Set P1000 = 2 for analog input frequency setpoint and confirm the signal level at the analog input terminals using a multimeter. Check DIP switch settings for voltage/current input mode on the control board.
Drive powers up but display (BOP/AOP) shows no response or remains blank
Check 24 V DC internal power supply. Verify the operator panel is fully seated on the drive. Inspect the ribbon connector between the panel and the drive control board.
Re-seat the operator panel firmly. If the display remains blank, test with a known-good BOP panel. If the drive itself shows no signs of power, check input fuses and the internal power supply board.
| Condition | Repair, Used, Refurbished, New in box (sealed) |
|---|