What this MCCB carries and where it fits
The Siemens 3VA1120-5EE32-0AA0 is a SENTRON 3-pole molded case circuit breaker rated 20 A continuous at 40 °C, with a TM220 thermal-magnetic release. It breaks up to 187 kA at 240 V AC, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 500/690 V — high-interrupting capacity that covers most industrial panelboard and distribution applications. The 70 mm depth, 76.2 mm width, and 130 mm height fit standard SENTRON mounting footprints, and the IP40 front protection suits enclosed panel mounting.
Interrupting capacity and release design
The 187 kA at 240 V is the headline number, but the 121 kA at 415 V is the one that matters for most three-phase 400 V distribution — that's well above typical available fault current in commercial and light industrial panels, so you get selectivity headroom without oversizing. The TM220 release is a fixed thermal-magnetic design: the thermal element handles overloads, the magnetic element handles short-circuits. No undervoltage release, no ground-fault monitoring, no communication function — this is a straight line-protection breaker, not a multifunction device.
Thermal derating and power loss
The 20 A rating holds flat from 40 °C to 55 °C, then derates to 19 A at 60–70 °C — no surprises for a panel running warm. Maximum power loss is 12 W, which is modest for a 20 A MCCB. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. Insulation voltage is rated 800 V, so it's fine for 690 V systems.