Current ratings and thermal derating
The 20 A rated current holds at 30 °C ambient. At 40 °C it derates to 18.6 A, at 45 °C to 17.6 A, at 50 °C to 17.2 A, and at 55 °C to 16.6 A. For a panel running warm — say 45 °C internal — the continuous load should not exceed 17.6 A per pole. Maximum power loss is 2.25 W.
Installation and wiring
Installation depth is 70 mm; the overall depth is 77 mm. Width is 126 mm (7 width units at 18 mm each), height 90 mm. Supply can enter from either top or bottom. Touch protection is integrated.