General
Product type	surge protector
Technology	Diode combination
Operating voltage	24 V DC
Compatibility	Contactors 3RT2.2

The overvoltage limiter 3RT2926-1ER00 from Siemens is a diode combination protection device for DC systems with 24 V. It is specifically designed for use with contactors of the 3RT2.2 series, which are integrated into the SIRIUS system building kit. The function is to limit transient overvoltages that occur when switching off inductive loads such as motors or coils, thereby protecting the electronic components in the contactor as well as in the connected system. The integrated diode combination diverts the voltage spike, thus increasing the service life of the contactors and connected control elements.

Overvoltage limiter
The overvoltage limiter operates as a passive protection mechanism that activates during sudden voltage spikes. It is designed for DC systems, particularly for operating voltages of 24 V DC. The diode combination enables efficient diversion of the inductive energy generated when interrupting a circuit with an inductive load. This prevents damage to sensitive semiconductor components in the contactor and control electronics.

Applications
The overvoltage limiter is primarily intended for use in industrial plants where motors, relays, or other inductive loads are controlled via 3RT2.2 contactors. It is used in automation technology, manufacturing industry, and in plants with electric drives, where switching off loads can cause transient voltage spikes. Its use within the SIRIUS system building kit enables modular and compact integration into existing control panels.

Functions and equipment in detail
The overvoltage limiter 3RT2926-1ER00 is designed as a modular component that is directly plugged into the mounting slot of the 3RT2.2 contactor. This mounting slot is already integrated into the contactor, so no additional mounting work or changes to the external dimensions of the control panel are required. The simple plug connection ensures quick and secure installation without tools. The diode combination is designed for an operating voltage of 24 V DC and provides reliable protection against overvoltages caused by inductive loads.

Technology explained simply
The diode combination in the overvoltage limiter works on the principle of voltage diversion. When a contactor interrupts an inductive load circuit, a high voltage spike is generated due to self-induction. The diodes in the device divert this voltage spike by providing an alternative current path for the inductive energy. This limits the voltage in the circuit to a tolerable level. The use of diodes enables a rapid response to voltage spikes that can occur within nanoseconds. The technology is particularly suitable for DC systems, as the diodes are able to control the direction of current flow and thus divert the voltage spike specifically.

Compatibility and accessories
The overvoltage limiter 3RT2926-1ER00 is exclusively intended for use with contactors of the 3RT2.2 series, which are part of the SIRIUS system building kit. Compatibility is based on the integrated mounting slot in the contactor, which can directly accommodate the overvoltage limiter. The device is used exclusively in combination with the specified contactors, and installation requires no additional mounting components.

Mounting and installation
Mounting of the overvoltage limiter is done by simply plugging it into the mounting slot of the 3RT2.2 contactor. This slot is already integrated into the contactor, so no additional drilling, screws, or mounting aids are required. Installation can be performed without tools and without affecting the external dimensions of the control panel. The connection is mechanically stable and ensures a secure electrical connection. The mounting position is fixed by the slot, so no additional positioning or adjustment is necessary.

Advantages in operation
The use of the overvoltage limiter 3RT2926-1ER00 leads to increased reliability and service life of the contactors and connected control elements. Avoiding overvoltages protects sensitive electronic components from damage caused by transient voltage spikes. The modular design enables quick and easy integration into existing installations, reducing maintenance and replacement times. Compatibility with the SIRIUS system building kit ensures a uniform and standardized solution widely used in industrial applications. The simple tool-free installation without changing the external dimensions of the control panel facilitates installation and maintenance in operation.