Siemens SINAMICS G120 Installation Manual page 54

Connecting
4.1 Permissible line supplies
Description
In unfavorable cases, the harmonic currents of several converters in the neutral conductor
(N) add up to a value greater than the currents of the line conductors (L1, L2, L3). The
current carrying capacity of the neutral conductor must be sufficient for this. IEC 60364-5-
52:2019, section 524, makes recommendations for sizing the neutral conductor. If no more
precise information is available, the standard recommends dimensioning the neutral
conductor for 1.45 times the current carrying capacity of the line conductors.
Fire caused by neutral conductor (N) overload
The neutral conductor can heat up due to the load from harmonic currents and cause a fire.
• Consider the harmonic currents when dimensioning the neutral conductor.
Electric shock caused by PEN conductor overload
In TN-C supply networks, the protective function of the PEN conductor can be adversely
affected by exposure to harmonic currents.
• Consider the harmonic currents when dimensioning the PEN conductor.
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CAUTION
WARNING
Hardware Installation Manual, 01/2020, A5E33294624B AL
Power Module PM240-2