What this MCCB carries and where it fits
The Siemens SENTRON 3VA1020-3ED32-0DC0 is a 3-pole molded case circuit breaker rated for 20 A continuous current (Iu) at 40 °C, with a TM210 thermal-magnetic release — that means the thermal element handles overloads and the magnetic element handles short-circuits, no separate trip unit to order. Breaking capacity runs 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 7.5 kA at 690 V — so on a 480 V panel it clears faults well above typical available fault current, and the 690 V rating covers 600 V class gear without derating. It includes an undervoltage release (UVR) as the auxiliary release design, plus two HQ auxiliary switches — that's a built-in shunt for undervoltage protection and two form-C contacts for status feedback to a PLC or indication lamp. Front protection is IP40, so it's fine for a dry indoor panel; the 70 mm depth, 76.2 mm width, and 130 mm height match the standard SENTRON 3VA footprint for retrofit into existing Siemens MCCB panels.
Thermal derating and operating range
Rated continuous current holds at 20 A from 40 °C up to 50 °C — no derating needed in a warm panel. At 55 °C it drops to 19.2 A, at 60 °C to 18.8 A, at 65 °C to 18.4 A, and at 70 °C to 18 A. That's a linear derating curve, easy to apply if your enclosure runs hot. Operating ambient range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The storage limit governs handling and warehousing, not running conditions.
What's on the nameplate vs what's inside
The overcurrent release is a TM210 — thermal-magnetic, fixed, non-interchangeable. No ground-fault monitoring module, no phase-failure detection, no communication function, and no voltage trigger. It's a straight line-protection breaker for standard distribution. The integrated auxiliary trip accessory is order code 3VA9608-0BB25 — if you need a replacement shunt or UVR coil, that's the separate part number. Latching endurance is rated at 15,000 operations.