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
Dimensions are 105 mm wide, 181 mm high, and 86 mm deep — a standard SENTRON 3VA2 frame footprint that mounts on DIN rail or can be screw-fixed to a backplate. The 86 mm depth is shallow enough to fit standard 200 mm deep enclosures without crowding the door clearance. 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. No undervoltage release, no ground fault monitoring, no communication module on this variant. Rated insulation voltage is 800 V, and the maximum power loss is 75 W. The latching endurance is rated at 20 000 operations — a mechanical endurance figure that matters for applications with frequent switching, such as compressor or pump cycling.
Lifecycle and compliance — current production
Operating temperature range is -25 °C to +70 °C, with storage from -40 °C to +80 °C. The 75 W maximum power loss should be factored into enclosure thermal calculations, particularly in sealed cabinets without forced ventilation.