MCCB for motor protection — 100 A frame, ETU350M trip unit
The Siemens SENTRON 3VA2110-5MN32-0KA0 is a 3-pole molded case circuit breaker (MCCB) rated for 100 A continuous current at 40 °C, with the same rating holding flat through 50 °C before a gentle thermal derating curve begins — 96 A at 55 °C, 94 A at 60 °C, 92 A at 65 °C, and 90 A at 70 °C. That means for most panel environments below 50 °C, you get the full 100 A without having to oversize the frame. This is the motor protection variant, fitted with the ETU350M electronic overcurrent release. The ETU350M provides adjustable thermal-magnetic or electronic protection curves suited to motor starting inrush, plus phase failure detection — a key requirement for three-phase motor circuits where a lost phase can single-phase a motor and burn the winding before a standard thermal overload reacts. Breaking capacity is substantial: 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 17 kA at 690 V. At typical 400 V class distribution voltages, the 121 kA SCCR gives generous headroom for high-fault installations without needing a current-limiting upstream fuse.
Integration and mounting — panel fit and auxiliary options
This order code ships without an auxiliary contact block (auxiliary contact version: Without) and without a trip indicator. The shunt trip (STL) is integrated as the auxiliary release design — part number 3VA9688-0BL33 for the auxiliary trip module, and the basic switch assembly is 3VA2110-5MN32-0AA0.
Lifecycle and compliance — current production
The 75 W maximum power loss should be factored into enclosure thermal calculations, particularly in sealed cabinets without forced ventilation.