What it is and what it does
The Siemens 3VA1125-5EE32-0AA0 is a SENTRON molded case circuit breaker (MCCB) rated for 25 A continuous at 40 °C ambient, in a 3-pole configuration. It uses a TM220 thermal-magnetic trip unit — the thermal element handles overloads, the magnetic element handles short circuits. This is a line-protection design, meaning it's meant for feeder circuits, not motor protection (no adjustable overload class). Breaking capacity is the headline: 187 kA at 240 V AC, 121 kA at 415 V, 75.6 kA at 440 V. That's a high-interrupting rating — it safely clears faults up to those levels without welding contacts or rupturing the case. For a 25 A frame, that's serious fault-current headroom, typical for main or sub-main distribution panels where available fault current is high. Rated insulation voltage is 800 V, and the breaker is rated for operation from -25 °C to 70 °C ambient. Power loss at rated load is 8.5 W maximum — useful for thermal calculations in a crowded enclosure.
Mounting and integration
Dimensions: 130 mm height, 76.2 mm width, 70 mm depth. The 3-pole width (76.2 mm) is standard for this frame size — it fits the typical panel cutout for a 3VA1 MCCB. Front protection is IP40, so it's fine for a dry indoor panel but not for washdown areas. No undervoltage release, no voltage trip, no communication function, no ground-fault monitoring version on this variant. It's a straight thermal-magnetic breaker with no accessories built in — add them externally if needed.