The 30 mA Type A residual current detection covers sinusoidal AC and pulsed DC fault currents, which is the standard requirement for circuits feeding electronics or single-phase rectified loads.
Rated 20 A at 30 °C, the 5SU1326-7FP20 derates to 18.4 A at 60 °C — a 1.6 A drop across the typical panel ambient range. If the device sits in a crowded enclosure near other heat sources, size the downstream load against the 60 °C figure, not the 30 °C headline. Installation depth of 70 mm plus conductor space fits typical 85 mm deep enclosures. Supply can enter from top or bottom — no mandatory orientation.