Siemens SINAMICS G120, S120 and Perfect Harmony Drives

Short answer

SINAMICS is the Siemens family of variable frequency drives. In low voltage, the G120C and G120 cover standard applications, the G120X is designed for pumping, ventilation and water, and the S120 for high performance. In medium voltage, the Perfect Harmony GH180 and GM150 now belong to Innomotics, the former large drives unit of Siemens. All control the speed of induction motors and integrate into plant automation.

What it is and where it is used

SINAMICS G120, G120C, G120X and S120 are the low-voltage variable frequency drives from Siemens, and SINAMICS Perfect Harmony GH180 and GM150 are the medium-voltage ones. A drive converts the fixed-frequency grid into a supply of variable frequency and voltage, to control the speed and torque of an induction motor. They are used on pumps, fans, compressors, conveyors, mills and extruders, in industry, mining, oil and gas, water and buildings.

Who owns it today? The low-voltage SINAMICS remain with Siemens. Since 1 July 2023, the large drives business, which includes the medium-voltage drives such as the Perfect Harmony GH180, is part of Innomotics. For the motor and its protections, see induction motor and its protections.

Variants: G120, G120C, G120X, S120, Perfect Harmony GH180 and GM150

Model	Application	Main difference
SINAMICS G120C	Compact general applications	Standard performance, 0.55 to 132 kW
SINAMICS G120	Modular general applications	Separate control unit and power module
SINAMICS G120X	Infrastructure: ventilation, pumping, water	Industry-specific, 0.75 to 630 kW
SINAMICS G180	Specific industrial applications	2.2 to 6,600 kW according to the catalog
SINAMICS S120	High performance and multi-axis systems	0.55 to 6,840 kW, also in cabinet modules
Perfect Harmony GH180	Medium voltage	Low-voltage cells in series, 2.3 to 11 kV according to Siemens
SINAMICS GM150	Medium voltage	Medium-voltage drive focused on cost and space

Main features

Speed and torque control of the motor, with soft starting and energy savings on variable-torque loads.
Converter and motor protections: overcurrent, thermal overload, DC bus voltage and ground faults, depending on the model.
Perfect Harmony GH180: input transformer with phase-shifted secondaries that reduces harmonics toward the grid, and a cell bypass function that lets it keep operating if a cell fails.
Integrated safety functions in several series, such as safe torque off.

A drive injects harmonics into the grid. If the plant has many, or if there are capacitor banks, a power quality study is advisable before connecting more drives.

How Siemens organizes the SINAMICS family

A Siemens presentation from May 2019 (in Romanian, with tables in English) and the SINAMICS G120 page on Siemens’ German site let us organize the family in three levels:

Level	Ranges	Use
SINAMICS V, basic performance	V20 (0.12 to 30 kW), V90 (servo drive)	Simple applications
SINAMICS G, general performance	G120, G120C, G120X, G120D, G130, G150	Pumps, fans, compressors, conveyors
SINAMICS S, high performance	S120, S210	Machining, positioning, multi-axis systems

Data from the presentation and from the G120 page that can be cited:

V20. USS and Modbus RTU communication; the V20 Smart Access web server module that turns a phone or laptop into a virtual operator panel; parameter download without powering the drive; and energy-saving and hibernation modes.
G120. Second modular generation, from 0.55 to 250 kW according to the presentation, with three voltage variants for 200, 400 and 690 V networks. It consists of the power module, the control unit and the operator panel, which can be combined with each other. Siemens’ German page lists safety functions (Safety Integrated) with SIL 2 according to EN 61508 and PL d according to EN ISO 13849-1, including STO, SS1, SBC, SLS, SDI and SSM, and integration in TIA Portal with Startdrive. That same page gives two different power ranges for the module (0.55 to 250 kW and 0.37 to 250 kW), so the exact range must be taken from the catalog.
G120C. Compact drive from 0.55 to 132 kW.
G120X. From 0.37 to 630 kW according to the table in the presentation (the text cites from 0.75 kW). It is delivered ready to switch on with a single order reference. It uses the smart access web server (SAM) and the IOP-2 panel. It has 3C3 coating and an operating temperature of -20 to 45 degrees Celsius (up to 60 with derating, and 55 for the PROFINET version). It meets EMC C1 and C2, has an integrated DC link choke and Safe Torque Off with SIL 3 hardware. It integrates with TIA Portal through a GSD file.
G110D and G120D. For decentralized applications, from 0.75 to 7.5 kW.
S210. Intermediate servo drive system with PROFINET IRT (250 microsecond cycle), basic and extended safety, and outputs from 0.05 kW (single-phase) to 7 kW (400 V three-phase), according to the progress of the presentation.
S120. Modular high-performance system with servo, vector and V/f control, integrated safety and positioning, and Profibus, PROFINET and EtherNet/IP communications; the 2019 presentation gives a range of 0.12 to 5,700 kW, and other sources cited above a higher maximum.

The figures in the presentation are from 2019 and those on the German page correspond to the edition in force when consulted; always confirm with the catalog and the order number of your unit.

Points of attention when selecting and commissioning

DC link choke. A drive with an integrated choke, such as the G120X, reduces harmonics toward the grid compared with one without it; to comply with IEEE 519 at the point of common coupling, the total distortion of the plant is calculated. See harmonics of variable frequency drives.
Functional safety. The SIL and PL levels of the STO and related functions are declared for the drive; the machine’s safety function is validated as a whole.
Long cable and motor. Cable length and the output filter affect motor insulation and bearings; see transient overvoltages in industrial plants.
Medium-voltage motor. When the drive is medium voltage, the motor, the cable and the input transformer are studied as a single system; see Siemens SIMOTICS motor and ABB medium-voltage motor.
Trips. Before blaming the drive, check the grid, the cable and the load; see VFD tripping.

Communications and integration

PROFINET and PROFIBUS with Siemens PLCs, and in several series EtherNet/IP and Modbus for other systems (Modbus RTU and TCP).
Configuration with Startdrive in TIA Portal for the current low-voltage series.
For the plant SCADA, the drive is read through the PLC or a gateway, with standardized statuses, measurements and alarms (PLC and automation).

Frequent technical questions

Which manual applies to the SINAMICS G120C?: the operating manuals and the parameter list are on the Siemens support portal; there is one manual per series and per firmware version.
Fault codes: each series has its list of faults and alarms in the parameter manual. A fault that repeats almost always points to the motor, the cable or the grid, not the drive.
Upstream protection trips at start or from harmonics: they are checked with the coordination and power quality study, not only with the drive parameters.
Motor tests: the insulation of the motor and cable is tested with the drive disconnected, because the electronics cannot withstand the test voltage.

How we help

We do not sell or repair drives. At Tiza Group we integrate the drive into the control system and the SCADA, coordinate its protections with those of the grid, test the motor and the cable and support the commissioning, in Colombia or elsewhere on request. See control, protection and communications configuration, motor testing and, if the problem is harmonics, power quality. Write to us through contact.

References

IEC 61800 (series), adjustable speed electrical power drive systems.
IEEE 519, harmonic control in electric power systems.
Siemens, catalogs of low-voltage SINAMICS converters, SINAMICS G120X and SINAMICS Perfect Harmony GH180.
Innomotics, catalog D 17 of SINAMICS Perfect Harmony GH180 (December 2023).

Frequently asked questions

What is the difference between the SINAMICS G120C and the G120X?

Siemens groups the G120C with the G120 in the standard performance range, for general applications from 0.55 to 132 kW. The G120X is a drive specific to infrastructure (ventilation, pumping, water and wastewater), from 0.75 to 630 kW according to the catalog.

Is the Perfect Harmony GH180 still a Siemens product?

Since 1 July 2023 the large drives business of Siemens, which includes the Perfect Harmony GH180, is part of Innomotics. That is why some documentation appears under one brand or the other.

What protects a motor fed by a drive?

The drive has its own motor and converter protections, but in medium voltage and in critical processes they are usually complemented by a motor protection relay and by coordination of the upstream protection. What is needed depends on the application and on the protection study.