Siemens SENTRON 3VA2450-6JQ32-0AA0 — 500 A MCCB with ETU560 Release
The Siemens 3VA2450-6JQ32-0AA0 is a SENTRON molded case circuit breaker (MCCB) rated for 500 A continuous current at 40 °C, with the same 500 A rating holding through 50 °C before derating begins — 477 A at 55 °C, 455 A at 60 °C, 432 A at 65 °C, and 410 A at 70 °C. This thermal stability across a 30 K band means the breaker does not force a frame-size upsizing for most panel ambient conditions; the 500 A rating is usable up to 50 °C without derating. Breaking capacity is specified per voltage: 242 kA at 240 V, 187 kA at both 415 V and 440 V, 121 kA at 500 V, and 9 kA at 690 V. The 187 kA figure at 415 V is the one that governs most European industrial distribution — it tells you this breaker can sit at the main incoming position in a high-fault panel without needing a current-limiting upstream device.
ETU560 Electronic Trip Unit — What It Means for Coordination
The overcurrent release is the ETU560, an electronic trip unit with communication function. Electronic trip units give you adjustable long-time, short-time, instantaneous, and ground-fault pickup and delay settings — not just the fixed thermal-magnetic curve of a standard MCCB. That adjustability is what makes selective coordination achievable downstream: you can set the short-time delay to ride through downstream faults up to the breaker's short-time withstand (6 kA for 1 s, per) without tripping the main. Rated insulation voltage is 800 V, which covers 690 V systems with margin. The 3-pole construction is standard for three-phase line protection. The ground-fault monitoring version uses summation current formation on the L-conductor — meaning it measures vector sum of the phase currents to detect leakage, not a separate neutral CT.
Physical Fit and Panel Integration
Dimensions are 248 mm height, 138 mm width, 110 mm depth. The 138 mm width is the 3-pole frame width — verify the mounting footprint against your existing switchboard or panel cutout. The IP40 rating on the front means the breaker face is protected against tools and wires >1 mm, but the enclosure itself must provide the overall panel IP rating. Maximum power loss is 99 W — account for that heat in the panel thermal calculation, especially if the breaker is enclosed with other heat sources.