The Siemens 5SU1644-1RC32 is an RCBO (residual current circuit breaker with overcurrent protection) rated 32 A, 4-pole, in an 8-module width, with a C characteristic and Type AC 300 mA residual current sensitivity. The Type AC 300 mA residual detects sinusoidal AC earth faults only, not pulsating or DC components, so it fits general-purpose distribution boards where no variable-speed drives or electronic loads are downstream.
Panel Integration
The 8-module width (roughly 144 mm on a standard DIN rail) means it occupies eight 18 mm pole spaces in the enclosure. For a 4-pole RCBO that is a compact footprint — typical for sub-distribution boards where space is tight.