Siemens SINAMICS G120XA 37kW Variable Frequency Drive

Technical Overview

37kW 3-phase AC 380-440V variable frequency drive with IP20, integrated Modbus RTU/BACnet/USS, and extensive I/O for pump/fan applications.

Key Features

Rated power of 37 kW with a 3-phase AC 380-440V input, providing robust motor control.
Integrated fieldbus communication protocols: MODBUS RTU, BACnet MS/TP, and USS for seamless system integration.
Features 6 standard digital inputs, 4 digital outputs (relay changeover contact), 2 analog/digital inputs, and 2 analog outputs.
Includes a dedicated motor temperature sensor input for PTC, KTY, PT1000, and Thermo-Click sensors.
IP20 protection degree, suitable for installation within a control cabinet.
Designed for reliable operation in harsh environments, with coated modules for increased resistance to humidity and dust (Class 3C2).
Supports a wide operating temperature range from -20 °C to +55 °C (or +60 °C with certain fieldbuses).
User-friendly setup options, including support for Intelligent Operator Panel (IOP-2) or the SINAMICS G120 Smart Access web server module.
Offers advanced functions such as continued run mode, hibernation mode, PID control for autonomous closed-loop operation, and skip frequencies.
Achieves high efficiency, up to 97% to 98%, contributing to energy savings.

Technical Specification Matrix

Parameter	Value
Input Number of Phases	3 AC
Line Voltage	380 ... 440 V +10 % -20 %
Line Frequency	47 ... 63 Hz
Rated Input Current (LO)	73.00 A
Output Number of Phases	3 AC
Rated Output Voltage	400 V
Rated Power IEC 400V (LO)	37.00 kW
Rated Output Current 400V (IN)	68.00 A
Max. Output Current	75.00 A
Pulse Frequency	4 kHz
Output Frequency for Vector Control	0 ... 240 Hz
Output Frequency for V/f Control	0 ... 550 Hz
Overload Capability (LO)	110% base load current IL for 60 s in a 600 s cycle time
Power Factor λ	0.75 ... 0.93
Power Factor cos φ 1	0.99
Efficiency η	0.97
Sound Pressure Level (1m)	62.2 dB
Power Loss	0.971 kW
Integrated Filter Class	Unfiltered
Protection Degree	IP20
Standard Digital Inputs (Number)	6
Digital Outputs (Relay Changeover Contact Number)	4 (DC 30 V, 1.0 A resistive load)
Analog / Digital Inputs (Number)	2 (Differential input, 12 bit resolution)
Analog Outputs (Number)	2 (Non-isolated output)
Motor Temperature Sensor Input	1 (PTC, KTY, PT1000, Thermo-Click compatible)
Communication Interfaces	USS, Modbus RTU, BACnet MS/TP
Ambient Operating Temperature	-20 °C to +55 °C (PROFINET, EtherNet/IP); -20 °C to +60 °C (USS, Modbus RTU, BACnet MS/TP)
Physical Weight (kg)	18.3
Dimensions L x W x H (cm)	23.9 x 20 x 47.2

Industrial Applications

1. Water Treatment Plant Pumping Stations

The SINAMICS G120XA can precisely control large centrifugal pumps in water treatment facilities to maintain optimal water flow and pressure through purification stages. Its 37 kW power rating handles significant pump loads, and the 380-440V input is standard for industrial pump motors. The integrated PID controller allows for autonomous closed-loop control based on tank levels or pressure sensors (using its 2 analog inputs and outputs), ensuring consistent water processing. The IP20 rating mandates installation within a control cabinet, protecting it from the dusty/humid environment of a pump house.

Problem Solved

Prevents over-pumping or under-pumping, reducing energy waste and wear on mechanical components, while ensuring consistent water supply and quality by maintaining precise flow and pressure.

Variable Frequency DrivePID Control3-phase AC37 kW380-440VIP20Analog InputsPump ControlWater Treatment

2. HVAC Air Handling Units (AHU) in Commercial Buildings

This drive can regulate the speed of large supply and exhaust fans within HVAC systems of commercial buildings. With a 37 kW output, it manages powerful fan motors for large-scale air circulation. The Modbus RTU and BACnet MS/TP communication protocols enable seamless integration with Building Management Systems (BMS), allowing the BMS to precisely adjust fan speeds based on air quality, temperature, or occupancy (using its digital and analog I/O for sensor feedback and control signals). This optimizes energy consumption and maintains comfortable indoor environments.

Problem Solved

Reduces energy consumption in HVAC systems by running fans only at the required speed, and provides precise environmental control, improving occupant comfort and air quality through adaptive airflow management.

Variable Frequency DriveHVACFan Control3-phase AC37 kWBACnet MS/TPModbus RTUIP20Digital InputsAnalog OutputsBuilding Management Systems

3. Industrial Compressor Control

In manufacturing or process industries, this drive can efficiently control the speed of a 37 kW compressor motor to match the compressed air demand. The 3-phase 380-440V input is common for industrial power, and the 110% overload capability for 60 seconds provides robustness against transient load spikes typical in compressor startup or fluctuating demand. Utilizing the drive's analog inputs for pressure feedback and its vector control capabilities (output frequency 0-240 Hz for vector control) allows for precise pressure regulation and energy savings by avoiding constant start/stop cycles of the compressor.

Problem Solved

Optimizes energy usage for compressed air systems by precisely matching compressor output to demand, reducing wear and tear on compressor components, and maintaining stable system pressure for critical industrial processes.

Variable Frequency DriveCompressor Control3-phase AC37 kW380-440VOverload CapabilityVector ControlAnalog InputPressure RegulationIndustrial Automation