What this MCCB does — and what the ratings mean for your panel
The Siemens SENTRON 3VA2110-7MS36-0HA0 is a 3-pole molded case circuit breaker (MCCB) in the starter protection version, designed to protect motor branch circuits and feeder lines in industrial distribution panels. It carries a rated continuous current Iu of 100 A, and the interrupting capacity hits 330 kA at 240 V — that is the fault current it can safely clear without welding contacts or rupturing the case. At 415 V and 440 V it still holds 242 kA, and at 690 V it is rated 52.5 kA. For a 100 A frame, those numbers put it in the high-interrupting category, meaning it can sit upstream of smaller breakers and still coordinate selectivity without needing a current-limiting fuse ahead of it. The ETU310M electronic overcurrent release gives it adjustable long-time, short-time, and instantaneous pickup settings — not just a fixed thermal-magnetic curve. That matters when you are protecting a motor: you can set the long-time pickup to ride through the inrush without nuisance tripping, and the short-time delay lets you coordinate with downstream starters or contactors. The shunt trip release (STL) allows remote tripping from an E-stop or PLC output, which is standard for safety circuits. No undervoltage release is fitted, so the breaker stays latched on loss of control power — a deliberate choice if you do not want the line to drop on a brownout.
Current ratings and thermal derating — the real continuous capability
At 40 °C, 45 °C, and 50 °C the breaker carries the full 100 A without derating. At 55 °C it drops to 96 A, at 60 °C to 94 A, at 65 °C to 92 A, and at 70 °C to 90 A (–). If your panel ambient runs above 50 °C — say a non-ventilated enclosure near a furnace line — you need to factor that 4–10 % reduction into the load calculation. The maximum operating temperature is 70 °C, so it will run in a hot cabinet, but you lose headroom. Storage range is -40 °C to 80 °C (–), which covers most warehouse and shipping conditions.
Physical fit — panel dimensions and mounting
The breaker measures 105 mm wide, 181 mm high, and 86 mm deep (–). That is a standard 3-pole MCCB footprint for the SENTRON 3VA frame — it fits the same cutout and bus-bar spacing as other 100 A 3VA units. No special adapter plate needed for a typical 600 mm wide distribution panel. The 86 mm depth means it clears most standard gland plates and backpanels without interference.