RCCB for 400 V three-phase panels
The 5SM3642-0LB: The 300 mA residual-current rating means this device is sized for protection against fire risk from earth faults, not direct personal shock protection (which typically calls for 30 mA). That makes it a fit for general-purpose distribution where the load is predominantly resistive or inductive AC, such as lighting, heating, and motor circuits with no rectified or variable-speed drive loads downstream.
Mounts on a DIN rail (REG) in any position — top or bottom supply feed is acceptable. The IP20 protection class applies when installed in a distribution board with conductors connected. The silicon-free designation matters for applications where outgassing from silicone compounds can contaminate contacts or optics, such as in automotive paint lines or clean-room environments.