SENTRON 3VA2125-6HM36-0AA0 — 25 A MCCB for Line Protection
The Siemens SENTRON 3VA2125-6HM36-0AA0 is a 3-pole molded case circuit breaker (MCCB) rated for 25 A continuous current, designed specifically for line protection in distribution panels. Its adjustable thermal trip range spans 38 A to 300 A, giving the specifying engineer flexibility to match the breaker to the actual load without swapping the frame. Breaking capacity is the headline here: 242 kA at 240 V AC, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 3.7 kA at 690 V. At 240 V, that 242 kA rating means this breaker can safely interrupt a fault current up to 242,000 A without rupturing — critical for high-fault installations near large transformers or in industrial mains. The steep drop to 3.7 kA at 690 V tells you this is a 240–500 V class device; at 690 V the interrupting capability is much lower, so verify the available fault current at that voltage before specifying. Ground-fault monitoring is built in via summation current formation on the L-conductor, which means the breaker can detect leakage by summing phase currents — no separate GFCI module needed for that function. The unit does not include undervoltage release or communication functions; it's a straightforward line-protection MCCB with no frills.
Panel Fit and Thermal Performance
Dimensions are 105 mm wide, 181 mm high, 86 mm deep — a standard SENTRON 3VA frame footprint that drops into existing Siemens panel layouts. The 86 mm depth (3.39 in) is shallow enough for most 200 mm deep enclosures, leaving room for wiring gutters. Operating temperature range is -25 °C to 70 °C, with no derating needed across the full 25 A rating from 40 °C through 70 °C — all temperature points show 25 A continuous, so the breaker holds its rating in warm cabinets. Maximum power loss is 0.6 W, negligible for thermal budgeting in a dense panel. Storage range is -40 °C to 80 °C, covering most warehouse and shipping conditions.