SENTRON 3VA2125-7JP32-0AA0 — 25 A MCCB with ETU550
The Siemens SENTRON 3VA2125-7JP32-0AA0 is a 3-pole molded case circuit breaker (MCCB) rated for 25 A continuous current across the full ambient range from 40 °C to 70 °C — no derating needed up to that ceiling. It carries the ETU550 electronic trip unit, which gives you adjustable overload and short-circuit protection curves rather than a fixed thermal-magnetic response. That matters when you need selectivity downstream of a larger feeder or want to coordinate with upstream relays without sacrificing nuisance-trip margin. Breaking capacity is the headline here: 330 kA at 240 V, 242 kA at 415/440 V, 187 kA at 500 V, and 3.7 kA at 690 V. Those numbers put it in the high-interrupting category — it clears faults up to 330 kA without venting or cascading upstream, which simplifies panel SCCR calculations in high-capacity distribution boards. The steep drop at 690 V (3.7 kA) is typical for a 25 A frame; at that voltage the arc extinction limits the rating, so verify your fault current at the service voltage before specifying.
Integration and mounting
The 3VA2125-7JP32-0AA0 measures 105 mm wide × 181 mm high × 86 mm deep. It mounts on a DIN rail or directly to a backplate via the fixed lugs. The IP40 front protection means it's suited for enclosed panel installation where the front face is behind a door — not for washdown or outdoor exposure without an additional enclosure. Communication function is onboard, so you can integrate it into a higher-level monitoring system without an external module. Power loss is listed at 0.6 W maximum — negligible for thermal budgeting inside a sealed panel, but worth noting if you're packing dozens of these into a small enclosure. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.
What the ETU550 trip unit gives you
The ETU550 is an electronic trip unit with LSI protection curves — long-time (overload), short-time (short-circuit with adjustable delay), and instantaneous. Unlike a thermal-magnetic breaker, the ETU550 lets you dial in the short-time pickup and delay, which is what you need for selective coordination in a multi-level distribution system. It also supports communication for remote monitoring of load current and trip events, though the exact protocol (PROFIBUS, PROFINET, Modbus) depends on the communication module fitted — the base breaker has the communication function enabled, but the specific interface card is ordered separately.