Heater
Power 6-9 kW for 8-15 m³ sauna. Dedicated 3-phase circuit: 5×6 mm², breaker C32-C40, from the panel with heat-resistant cable.
Zones
Zone 1 — above the heater: nothing but the heater and its controls at a safe distance. Lighting — SELV 12-24 V, IP65.
Heat-resistant cable
In the sauna zone — RKGM/RCGN cable, heat-resistant to 180 °C, not VVG. The junction box — outside the sauna.
RCD
Sauna circuit — RCD 10-30 mA per PUE. The heater — with thermal protection and a limiter.
Lighting
SELV 12-24 V with the transformer outside the sauna. IP65 fixtures. No sockets in the steam room.
Why design
A sauna mistake — fire or electric shock in wet heat. The design checks the cable, RCD and zones.