What this 3VA MCCB is and what it does
The Siemens SENTRON 3VA1110-5MH36-0AA0 is a 3-pole molded case circuit breaker (MCCB) rated at 100 A at 40 °C. It uses a TM120M thermal-magnetic overcurrent release — the thermal element handles overloads, the magnetic element handles short circuits. That's the workhorse trip unit for general distribution and motor branch protection where you don't need electronic adjustability. Breaking capacity is the headline number that decides whether this breaker clears a fault without blowing up. At 240 V AC it's rated for 187 kA; at 415 V AC it's 121 kA; at 440 V AC it's 75.6 kA; at 500 V and 690 V AC it holds at 7.5 kA. That 187 kA at 240 V is a high-interrupting rating — it's sized for large transformer secondaries or high-fault industrial panels where a standard 65 kA or 100 kA breaker won't hold coordination. Rated insulation voltage is 800 V, and the maximum operating voltage is 690 V AC. That puts it squarely in the 480/277 V and 600 V industrial distribution world — it's not a 1 kV solar breaker. Power loss is 25 W maximum, which matters for enclosure heat rise in a packed panel.
Temperature derating — the real ampacity on your panel
This breaker is listed at 100 A from 40 °C up through 50 °C. At 55 °C it drops to 98 A; at 60 °C it's 96 A; at 65 °C it's 94 A; at 70 °C it's 91 A. That's a shallow derating curve — you lose only 9 A over a 30 °C rise above 40 °C. That means in a warm enclosure or near a motor starter you don't have to oversize the frame just to hold the load. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The IP40 front protection means it's fine in a dry indoor panel but not for washdown areas — that's the panel builder's call on gland plates and gaskets.
Dimensions and panel fit
The breaker measures 130 mm high, 76.2 mm wide (3 inches), and 70 mm deep. That 3-inch width is the standard 3-pole MCCB footprint for this frame size — it fits the same cutout and busbar spacing as other SENTRON 3VA 100 A frames. Depth of 70 mm means it clears most shallow backpan enclosures without a sub-panel extension.