Switch and protect motors intelligently

Fully electronic motor starters, such as the Simatic ET 200SP e-Starter now being presented by Siemens for the first time, offer a promising solution in such short-circuit-prone environments. Whether in the food and beverage industry, intralogistics or mechanical engineering - it is not least the current EU eco-design regulations that have ensured that highly efficient three-phase asynchronous motors, or three-phase motors for short, continue to gain ground and are now a driving force in all industries. Malfunctions and failures can quickly lead to considerable damage and costs. Against this background, motor starters play an important role: they start motors reliably and protect them from overloads and short circuits.

Conventional electromechanical switching and protective devices switch off safely, but the device is usually no longer operational and the entire system is at a standstill until the component is replaced. Until now, there has been no real alternative, especially for applications with a generally increased risk of short circuits.

With this in mind, Siemens Smart Infrastructure launched a fully electronic starter with semiconductor technology for the first time in 2024: the Simatic ET 200SP e-Starter. Already a leading provider of hybrid switching devices, Siemens is now taking a fundamental step further with a fully electronic product: the new development, which was created in close consultation with potential users, uses semiconductor technology with SiC MOSFETS (silicon carbide metal-oxide semiconductor field-effect transistors) and combines modern power semiconductors, powerful microcontrollers and ultra-fast-responding electronics. The recently introduced fully electronic protective switching device Sentron ECPD is also based on this principle.

Full protection in a short time

As a result, the Simatic ET 200SP e-Starter is characterized by short-circuit protection that is up to a thousand times faster than conventional solutions and is virtually wear-free. This ensures long-term protection for motors and other types of loads and the applications operated with them. The practical advantages are obvious: because the fully electronic e-starter detects a short-circuit in less than 5 µs and switches off the power semiconductors, a high and potentially dangerous short-circuit current cannot even occur in the event of a short-circuit. This significantly reduces the electrical load on the feeder. In addition, no mechanical components can wear out. The device therefore does not need to be replaced, but is ready to be switched on again immediately after the fault has been rectified. This not only increases the availability and productivity of machines and systems, but also reduces the effort and costs involved in maintaining and stocking replacement devices. The integrated Smart Start of the Simatic ET 200SP e-Starter significantly reduces starting currents and thus also the associated torque surges during the starting process. Damage to the drive mechanism is greatly reduced. Phase-optimized switching of the semiconductors neutralizes the inrush currents, which prevents false tripping.