What this MCCB is and what it protects
The Siemens 3VA1110-4EF46-0AA0 is a SENTRON molded case circuit breaker (MCCB) in a 4-pole configuration, rated for 100 A continuous current (Iu) and fitted with a TM240 thermal-magnetic fixed-trip release. It is the line-protection version, meaning it is designed to protect cables and distribution buswork from overload and short-circuit faults — not motor or generator protection, which would use a different release curve. The TM240 release provides an adjustable long-time pickup (Ir) up to 1000 A and a fixed magnetic instantaneous trip. The 4-pole construction covers three-phase plus neutral switching, common in North American and IEC distribution panels where the neutral must be switched or isolated.
Interrupting capacity — where it clears faults
This MCCB delivers 121 kA interrupting capacity at 240 V AC, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at both 500 V and 690 V. Those numbers tell you the maximum fault current the breaker can safely interrupt at each voltage level without welding contacts or rupturing the case. For a 480 V panel with a 65 kA available fault current, this breaker has headroom; for a 240 V service entrance with 100 kA available, it still holds. Rated insulation voltage (Ui) is 800 V, and the maximum operational voltage for DC circuits is 600 V — relevant if this breaker lands in a battery or UPS distribution cabinet.
Thermal derating — what 100 A means at panel ambient
The 100 A continuous rating holds at 45 °C and 50 °C ambient. Above that, derating kicks in: 98 A at 55 °C, 96 A at 60 °C, 94 A at 65 °C, and 91 A at 70 °C. If the panel runs hot — say a non-ventilated enclosure near a molding press — the effective ampacity drops. Plan the load at 91 A if the enclosure ambient hits 70 °C, not the nameplate 100 A. Maximum power loss is 25 W. That's the heat the breaker dumps into the panel at full rated current — a factor for enclosure thermal calculations, especially in sealed cabinets.
Physical fit and panel integration
Dimensions are 130 mm high, 101.6 mm wide, 70 mm deep. The 4-pole width of roughly 4 inches (101.6 mm) is standard for this frame size. It mounts on a DIN rail or directly to a backplate via the breaker's own mounting lugs. IP40 on the front means protection against tools and wires >1 mm — typical for a panelboard interior, but not washdown-rated.