The KOSTAL BackUp Switch G3 is a compact manual backup switch designed for use with KOSTAL PLENTICORE G3 hybrid inverter systems. In combination with a connected battery and available solar energy, it allows selected household loads to continue receiving power during a grid outage.

Installed within the building’s electrical distribution system and connected to the inverter, the BackUp Switch G3 enables a manual changeover to backup operation in the event of a power failure. This makes it a practical solution for homeowners who want greater energy security and the ability to supply important circuits when the public grid is unavailable.

The unit is compatible with all PLENTICORE G3 series inverters and features a space-saving design requiring only 8 DIN rail modules, allowing it to fit neatly on the same top-hat rail as the KOSTAL Smart Energy Meter. It can be installed either in an existing sub-distribution board or in a separate enclosure, depending on the application.

Key benefits

• Designed for KOSTAL PLENTICORE G3 systems

• Manual 3-phase mains changeover switch

• Enables backup supply for selected household loads during grid failure

• Compatible with systems using solar energy and a connected battery

• Compact 8-module DIN rail design

• Can be installed in an existing sub-distribution board or separate housing

• Separate outputs for backup loads and loads remaining on normal grid operation

• Suitable for house connections up to 63A

• Supports connection of a local neutral point replica

• Includes integrated cable break detection for switch position evaluation signal

User-friendly information

The KOSTAL BackUp Switch G3 is a good choice for users who want a clear and reliable manual backup solution for their PLENTICORE G3 system. During normal operation, all connected loads remain supplied by the public grid as usual. In the event of a power outage, the switch allows the inverter to supply the designated backup branch, while loads assigned to the normal grid branch remain separated accordingly.

Because the switch is manual, the changeover is performed by the user or installer rather than automatically. This makes it a straightforward and robust solution for applications where controlled manual backup activation is preferred. The rotary switch has a 90° switching angle and a handle interlock in the OFF position.

Technical highlights

• Grid connection: 3N~, 230/400 V, 50 Hz

• Public grid form: TN/TT

• Island grid form: TN-S

• Continuous current: 63 A

• Operating voltage: 400 V AC

• Operating power: 22 kW at AC-23A, 400 V

• Dimensions (W x H x D): 144 x 102 x 97 mm

• Weight: 520 g

• Warranty: 2 years

• Certifications / standards: DIN EN IEC 60947-3, DIN EN IEC 60947-6-1, VDE-AR-E 2510-2

Installation notes

• Installation and maintenance must be carried out only by competent and authorized personnel

• Maximum rating is 400 V / 63 A

• After installation, the BackUp Switch must be activated in the inverter settings via the operating mode menu

• The operating mode change can only be performed by an installer