Selective RCCB for 4-pole 400 V AC circuits
The Siemens 5SV3444-8LA is a 4-pole selective residual current circuit breaker (RCCB) from the SENTRON series, rated 40 A with a 100 mA residual operating current for 400 V AC systems at 50/60 Hz. The selective design (Type S) means it incorporates a short time delay so that downstream RCCBs trip first during a ground fault, keeping this unit as the backup — critical for maintaining supply to upstream loads in a distribution board where you want only the faulted branch isolated. The 4-pole configuration handles three-phase plus neutral, so it fits three-phase 400 V distribution where all live conductors need residual protection.
Depth is 70 mm, installation depth also 70 mm. Supply connection can be top or bottom, giving flexibility in busbar routing.
40 A rated current at 400 V AC. The 100 mA residual sensitivity is for equipment protection or as a time-delayed upstream RCCB. The selective characteristic coordinates with downstream RCCBs. Mechanical service life of 10,000 operating cycles typical. Ambient temperature range -25 °C to +45 °C operating, -40 °C storage. Silicon-free construction for applications sensitive to silicone outgassing (e.g., paint shops, electronics assembly).