What this MCCB is and what it does
The Siemens 3VA2110-5MN32-0AD0 is a SENTRON molded case circuit breaker (MCCB) in the motor protection version, meaning it is built to protect motor circuits from overloads and short circuits with a dedicated electronic trip unit. It carries a rated continuous current Iu of 100 A and a rated insulation voltage Ui of 800 V, so it handles standard 400 VAC motor feeders comfortably. The 187 kA breaking capacity at 240 V and 121 kA at 415 V give it headroom for high-fault installations like transformer secondaries or large distribution boards where the available fault current is substantial. At 690 V the breaking capacity drops to 17 kA — still adequate for most 690 V motor circuits, but worth checking against the transformer rating.
Thermal derating and real-world current
This breaker is rated 100 A continuously up to 50 °C ambient. Above that it derates: 96 A at 55 °C, 94 A at 60 °C, 92 A at 65 °C, and 90 A at 70 °C. If the panel runs hot — say a crowded enclosure with drives — the 70 °C figure is the one to size against. The maximum power loss is 75 W, which adds to the enclosure heat load and should be factored into the thermal design.
Trip unit and auxiliary contacts
The overcurrent release is the ETU350M, an electronic trip unit with phase failure detection — it will trip on loss of a phase, which is critical for motor protection where single-phasing can burn out a winding. The breaker ships with 3 auxiliary switches HQ (high-qualified) for status feedback to a PLC or indication panel. There is no undervoltage release, no ground fault monitoring, and no communication function built in; those would need add-on modules. The integrated auxiliary trip is order code 3VA9608-0BB24, and the supplied basic switch is 3VA2110-5MN32-0AA0.
Panel fit and mechanicals
The breaker measures 105 mm wide, 181 mm high, and 86 mm deep — a standard 3-pole MCCB footprint that fits most DIN-rail or panel-mount enclosures without surprises. The latching endurance is rated at 20 000 operations, which is typical for a motor-protection MCCB in a panel that sees regular switching. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.