Its C tripping characteristic handles moderate inrush currents — typical for motor starters, contactor coils, and small transformers — while the 20 A rating at 35 °C (19 A at 40 °C) sets the continuous load limit.
Sizing and derating for the panel
The 5SY5220-7CC occupies 2 modular width units (36 mm) on a DIN rail, with a depth of 76 mm and an installation depth of 70 mm. It mounts in any position and uses a quick-assembly fastening system — no tools needed for rail snap-on. Ambient temperature derating is published: 20 A at 35 °C, 19 A at 40 °C, 18.48 A at 45 °C, 17.96 A at 50 °C, 17.4 A at 55 °C.