What it is and why the ratings matter
The Siemens 3VA2110-5KP32-0CC0 is a SENTRON molded case circuit breaker (MCCB) built for line protection in distribution panels. Three poles, 100 A rated continuous current (Iu), and an ETU850 electronic trip unit — that combination tells you it's a microprocessor-based breaker, not a thermal-magnetic, so you can dial in the trip curve to coordinate with downstream devices. The interrupting capacity climbs to 187 kA at 240 V and stays at 121 kA through 440 V; at 690 V it still clears 4.25 kA. That's a lot of fault energy for a 100 A frame, meaning it's sized for high-available-fault panels where a standard MCCB would weld itself shut. Thermal derating is published all the way to 70 °C ambient: it holds 100 A flat from 40 °C to 50 °C, then drops to 96.25 A at 55 °C, 92.5 A at 60 °C, 88.75 A at 65 °C, and 85 A at 70 °C. If the panel runs hot — say a packed enclosure near a furnace line — that curve tells you exactly where you land without guessing.
Panel fit and integration
The breaker occupies 105 mm width, 181 mm height, and 86 mm depth. That's a standard SENTRON 3VA frame footprint — mounts on a DIN rail or bolts directly into the panel backplate. The depth matters when you're up against a gland plate or a shallow enclosure door; 86 mm leaves room for cable bends and the undervoltage release module that comes fitted on this variant. Two auxiliary switches (HQ type) are built in, plus an undervoltage release (UVR) — the UVR coil pulls from the control voltage and drops the breaker if the supply dips, which is standard for safety circuits that need a loss-of-voltage trip. Communication function and other measurement functions are present, so this breaker can report status and energy data back to a BMS or PLC without a separate metering module.
What's on the van — field-service perspective
If you're swapping this into an existing panel, the key gotcha is the undervoltage release: it needs a control voltage to hold the breaker closed. No control power means the breaker stays tripped, which is the intended behaviour but can surprise someone who expects a plain thermal-magnetic that stays latched. The ETU850 is programmable via the front keypad or software, so you can adjust long-time, short-time, instantaneous, and ground-fault settings without swapping trip units. Power loss is 12.5 W max — negligible for thermal budgeting in a ventilated enclosure. Operating range is -25 °C to 70 °C; storage goes from -40 °C to 80 °C. That covers most indoor industrial environments, including unheated warehouses. The 20 000 mechanical endurance cycles mean it's rated for switching duty, not just backup protection — it'll handle regular load-break operations on a production line.