Electrotechnically instructed person (EuP)
Only work under the direction and supervision of an electrical specialist when the battery systems or low-voltage modules are de-energized or carry out non-electrical work in the vicinity (safe distance) of active parts.

Electrical specialist for defined tasks (ESfdt)
Carry out standardized electrical engineering work independently, incl. Disconnect and commission (e.g. low-voltage switchgear, inverters). However, with the restriction: Only according to work instructions (checklist). Live line work is only permitted with the additional qualification LLW.

Electrical specialist (ES)
The electrical specialist carries out the necessary work independently, including Troubleshooting. Can and may also independently select suitable work equipment. Appropriate maintenance of professional competence must be ensured. The corresponding additional qualification is required for live line work.

Live line work (LLW) on battery systems
Additional qualification for ES and ESfdt for authorization to perform live line work, if required.
This is not uncommon in systems such as battery systems, as a battery system always supplies voltage due to its electrochemistry.

Chief responsible electrical specialist (CRES)
The chief responsible electrical specialist assumes corporate responsibility for electrical safety. Depending on the responsibility, this can affect both the construction of the battery systems and their operation.