MCCB for line protection — 20 A, 4-pole, high interrupting capacity
The Siemens 3VA1120-4ED46-0AA0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection in distribution panels. It carries a continuous current rating of 20 A across an ambient range of 40 °C to 55 °C, derating to 19 A at 60 °C through 70 °C — so the full 20 A holds in most ventilated enclosures without headroom loss. The 4-pole configuration handles three-phase-plus-neutral or three-phase with a switched neutral, common in North American and European panel builds. Breaking capacity is the standout: 121 kA at 240 V AC, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at 500 V and 690 V. That 121 kA figure at 240 V means it can interrupt a fault on a high-capacity transformer secondary without upstream fuses — a real advantage for main or feeder positions where available fault current is high. The TM210 thermal-magnetic release (fixed thermal, fixed magnetic) is set for line protection, not motor starting; no adjustment needed, no mis-coordination risk.
Integration and mounting
The breaker measures 70 mm deep, 101.6 mm wide, and 130 mm high — a compact footprint that fits standard panel-mount cutouts for 4-pole MCCBs. Front IP40 protection means it is suited for general indoor panel environments where tools or fingers might contact the front face but not for washdown or outdoor exposure. Rated insulation voltage is 800 V, so it can be applied in 480/277 V and 600 V systems with margin. Maximum power loss is 12 W, which is modest for a 4-pole 20 A device — panel thermal rise stays manageable even in densely packed enclosures.