Our customers manage great values ​​and expect full control over their systems. Our experience gives confidence that their interests are taken care of.

Wolfgang Trötscher working on VSD 45kW

Responsive & Ready to Rock.

Nebb delivers complete control systems for subsea systems, including topside control rooms.

The Nebb design principle is to go for robust, common-off-the-shelf (COTS) components in the subsea electronic module. The COTS and standard components are used throughout to create a cost-effective, reliable, and maintainable solution. 


Subsea safety control modules

Designed with common-off-the-shelf (COTS) components, the subsea safety control module provides a reliable and safe solution.  

The Functional Safety Programming tool is a part of the selected hardware components. It uses programming "blocks" that are TüV Rheinland certified according to IEC 61508.

The ESD & EQD shall be programmed to a predefined sequence with safety analog inputs to perform a safety action.


Subsea Electronics Module

The SEM includes standard COTS components in a “sleeved” design of payload. The payload is mounted to the top lid, providing easy access to the components with minimal need for any electrical disconnections.

The NEBB SEM comes with Modbus TCP Fieldbus support to be interfaced with RIO/networking switch. Configurable DI/DO/AO is also available for use if necessary.

An insulation monitoring device is installed for monitoring the 24V DC auxiliary supply of the SEM.

A modular RIO system made especially for harsh applications is used and can be expanded upon customer needs. 


Nebb VSD-narrow


Subsea Battery UPS

The subsea battery UPS consists of several Li-ion cells, with a complete charging unit and battery management system. The subsea battery is contained in a separate 300 bar pressure housing to be interfaced with the safety SEM.

The UPS operates in "online" mode, hence is connected in series with the external 24V power supply. The power is fed through the UPS and to the safety SEM.

  • The UPS has two modes of operation:
    Idle: Power is taken from the UPS input, regulated to steady 24V, and delivered to the SEM. (battery is not activated in this mode).
  • Power failure: When there is no power available on the UPS input, it will go into power failure mode. The battery will activate to supply a steady 24V on the UPS output to feed the safety SEM.


  • Qualified according to
    • ISO 13628-6
    • API 17F
  • Operating depth: 0-3000m.
  • EMC compliance to
  • Overload protection
  • Functional Safety IEC 61508
  • RoHS IEC63000:2016
  • No 765/2008 CE marking

Key characteristics

  • Small - low complexity compared to custom solutions.
  • Proven - Consisting of COTS providing field-proven components.
  • Robust - tolerate vibration, shock, and electrical fluctuations. 
  • Dual barrier - seals for canister and connectors.