What this MCCB carries and where it fits
The Siemens 3VA1180-5EF36-0AF0 is a SENTRON molded case circuit breaker built for line protection — 3-pole, rated 80 A continuous at 40 °C, with a TM240 thermal-magnetic release that handles overloads and short-circuits in one package. At 240 V it interrupts up to 187 kA, which gives serious fault-current headroom for a panel fed close to a large transformer. The interrupting rating drops to 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 500 V or 690 V — still solid numbers for most industrial service entrances. Rated insulation voltage is 800 V, so the breaker is comfortable on 480/277 V or 600 V systems without derating the insulation path. The TM240 release is fixed-thermal, fixed-magnetic — no field-adjustable trip settings, which simplifies spec-in for a BOM line that needs a known coordination curve.
Thermal derating and panel fit
The 80 A rating holds flat from 40 °C through 50 °C. Above that it derates gradually: 78 A at 55 °C, 77 A at 60 °C, 75 A at 65 °C, 74 A at 70 °C. If the panel ambient runs hot — say a sealed enclosure next to a furnace line — you lose about 6 A by the time you hit 70 °C. That's predictable and easy to factor into the load calculation. Footprint is 130 mm tall, 76.2 mm wide, 70 mm deep — standard 3-pole MCCB envelope that drops onto a DIN rail or direct-mount plate. The 76.2 mm width (3 inches) is the same as most SENTRON 3VA1 frames, so swapping into an existing panel with a different 3VA1 variant usually lines up with the bus bars and lug kit. Power loss at full load is 19.2 W maximum. That's moderate for an 80 A frame — the heat stays manageable inside a ventilated enclosure, but worth noting for a sealed stainless panel where every watt adds to the cooling budget.
Built-in auxiliary and alarm switching
This version ships with 1 auxiliary switch plus 1 trip alarm switch (HQ designation). That gives remote status on both the breaker position and whether it tripped on fault — useful for a PLC input or a remote annunciator panel without adding a separate accessory module. No undervoltage release, no ground-fault monitoring, no communication module on this variant. It's a straight line-protection breaker with basic aux contacts — the kind that goes into a distribution sub-panel where you need the trip alarm but don't need network connectivity or GF protection.