Zone 0 and Zone 1

In order to ensure the safety of bathers and those around the pool, areas are defined in pools where only SELV (Safety Extra Low-Voltage) can be used.
This voltage cannot exceed 12 V AC (alternate current) or 30 V DC (direct current).
In zones 0 and 1, only protection by SELV circuits with the safety source installed outside zones 0 and 1, or installed in zone 2 if its power supply circuit is protected by a differential protection device with a nominal differential current not exceeding 30 mA, is allowed.
Junctions are not allowed in zones 0 and 1. Junction boxes are only allowed in zone 1 if the circuits are SELV.
The reference standard is CEI 64-8. For further information, consult the link.