TN system - Protection in high fire-risk locations
From Electrical Installation Guide
According to IEC 60364-422-3.10, circuits in high fire-risk locations must be protected by RCDs of sensitivity ≤ 500 mA. This excludes the TN-C arrangement and TN-S must be adopted.
A preferred sensitivity of 300 mA is mandatory in some countries (see Fig. F47).
Fig. F47: Fire-risk location
