What this MCCB brings to the panel
The Siemens 3VA1125-4EE32-0AA0 is a SENTRON molded case circuit breaker (MCCB) built for line protection in distribution panels. It's a 3-pole unit rated 25 A at 40 °C, with a TM220 thermal-magnetic release — the thermal element handles overloads, the magnetic element clears short-circuits. The interrupting ratings are the headline: 121 kA at 240 VAC, 75.6 kA at 415 VAC, and still 11.9 kA at 690 VAC. That kind of SCCR headroom means it can sit upstream of a high-fault transformer or a large motor starter without worrying about cascading failure.
Sizing and thermal derating
At 40 °C you get the full 25 A. The TM220 holds that rating through 50 °C, then drops to 24 A at 55 °C and 23 A at 70 °C. If your panel ambient runs hot — say a packed enclosure near a furnace line — factor that 2 A loss. The insulation voltage is rated 800 V, so it's comfortable on 690 V systems.
Panel fit and dimensions
The 3VA1125-4EE32-0AA0 measures 70 mm deep, 76.2 mm wide, and 130 mm tall. That's a standard SENTRON 3VA footprint — it clips onto a DIN rail or bolts into a mounting plate. The front face carries an IP40 rating, so it's fine inside a closed panel but not for washdown zones. No undervoltage release or communication module on this variant; it's a straight line-protection breaker with a TM220 trip unit.