SENTRON 3VA with ETU550 — what the ratings mean for your panel
The Siemens SENTRON 3VA2125-7JP36-0AA0 is a 3-pole molded case circuit breaker (MCCB) rated for 25 A continuous current, with a flat thermal derating curve from 40 °C through 70 °C ambient — meaning no capacity loss in a warm enclosure as long as you stay within that range. It carries the ETU550 electronic trip unit, which gives you adjustable overload and short-circuit protection settings rather than fixed thermal-magnetic curves — useful for coordinating downstream breakers or accommodating motor inrush without nuisance trips. The interrupting ratings are substantial: 330 kA at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 3.7 kA at 690 V. That 330 kA figure at 240 V means it can safely clear a fault on a high-capacity transformer secondary without needing a current-limiting fuse upstream. The adjustable current range spans 38 A minimum to 300 A maximum, so the same breaker frame covers multiple tap sizes — a single line-item for the BOM that you set at commissioning.
Panel fit and communication
Dimensions are 105 mm wide, 181 mm high, 86 mm deep — a standard 3-pole MCCB footprint that drops into SENTRON distribution panels and most DIN-rail adapter plates without re-drilling. Front-face protection is IP40, adequate for enclosed switchboards. This variant includes a communication function, which on the 3VA platform typically means a modular communication-capable trip unit that can report status and measured values over a bus — useful for power monitoring without adding a separate meter.
Lifecycle and sourcing reality
The lifecycle stage is listed as current production — this is an active catalog number, not a phase-out or last-time-buy item. It is sourced through independent distribution and quoted to order against an RFQ; availability and current pricing are confirmed at quote time.