What the interrupting ratings mean for your panel coordination
The Siemens 3VA1150-4EF36-0KH0 is a 3-pole SENTRON molded case circuit breaker rated for line protection, carrying 50 A continuously at 40 °C without derating. Its interrupting capacity hits 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, and holds 11.9 kA all the way up to 690 V — so it handles high-fault scenarios across common industrial voltage levels without needing an upstream current-limiting fuse. That SCCR headroom means you can coordinate downstream branch breakers with confidence, especially on 480 V or 400 V distribution where fault currents can exceed 50 kA. Thermal derating is mild: the breaker holds full 50 A up to 50 °C, then drops to 49 A at 55 °C, 48 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. In a warm enclosure near the top of a panel, you lose only 5 A — plan your continuous load at 45 A if ambient hits 70 °C.
Auxiliary switches and shunt trip — what's inside
This variant ships with a shunt trip (STL) release and a pre-configured auxiliary switch block: 2 auxiliary switches plus 1 trip alarm switch HQ. The shunt trip lets you remotely trip the breaker via a control voltage — useful for emergency-stop circuits or interlocking with a VFD safety relay. The auxiliary contacts provide status feedback (open/closed/tripped) to a PLC or annunciator panel. No undervoltage release is fitted, so if you need UVR for machine-restart prevention, this isn't the variant. The base switch is order code 3VA11504EF360AA0 — that's the core mechanism this assembly builds on. Communication function is absent; this is a standalone breaker, not a 3VA2 with PROFIBUS or Modbus.
Panel fit — dimensions and mounting
Footprint is 76.2 mm wide (3 in), 130 mm tall (5.12 in), and 70 mm deep (2.76 in). That's a standard SENTRON 3VA1 three-pole width — it snaps onto a DIN rail or mounts with screws onto a backplate. The 70 mm depth leaves clearance for wiring gutters and busbar connections; no need to oversize the enclosure just for this breaker.