3. Neutral system

3.1 Low-voltage neutral system

A genset must be subject to the same neutral system as the installation it will be backing up. However, there is a special case to consider:

• when several groups are coupled in parallel, if the alternators are wound in full pitch (close to the diametral pitch), not all the alternator neutrals must be earthed. This arrangement leads either to the circulation of high harmonic currents 3.

If the installation requires a grounded neutral system, there are two possible solutions:...