32 A MCCB with 220 kA interrupting capacity — what that means for your panel
The Siemens SENTRON 3VA1132-6EF36-0AD0 is a 3-pole molded case circuit breaker rated for a continuous current Iu of 32 A, carrying a TM240 thermal-magnetic release that handles overload and short-circuit protection in one device. What sets this unit apart is the interrupting capacity: 220 kA at 240 V, 154 kA at 415 V, and 121 kA at 440 V — figures that place it in the high-fault category, suitable for installation close to large transformers or in high-available-fault-current industrial distribution boards where a standard MCCB would cascade. The TM240 release is non-adjustable for the thermal element — fixed at 32 A — so the breaker is sized for a specific load and not meant for field re-rating. The magnetic trip threshold is factory-set for the 240 A range, giving short-circuit protection that clears fast on high faults without nuisance tripping on motor inrush. Rated insulation voltage Ui is 800 V, and the breaker carries 3 auxiliary switches HQ for status feedback to a PLC or annunciator panel. No undervoltage release, no shunt trip, no ground-fault module on this variant — it's a straight line-protection device with aux contacts for remote indication.
Thermal derating and ambient temperature — the real-world current limit
The 32 A rating holds from 40 °C through 50 °C ambient, then derates linearly: 30.72 A at 55 °C, 30.08 A at 60 °C, 29.44 A at 65 °C, and 28.8 A at 70 °C. For a panel that runs hot — say, a packed enclosure near a furnace line or in a rooftop unit — the effective continuous current drops by about 10% at the upper end. The storage range is -40 °C to 80 °C, wider than the operating range, which matters for spares kept in unheated warehouses. Front IP40 protection means the breaker face is sealed against tools and solid objects >1 mm, but not against moisture — fine for a dry indoor panel; not rated for washdown or outdoor exposure without a secondary enclosure.
Mounting and panel fit — 76.2 mm wide, 130 mm tall, 70 mm deep
The breaker occupies 76.2 mm of DIN-rail width (3-pole, standard 25.4 mm per pole), stands 130 mm tall, and projects 70 mm from the mounting surface. That depth leaves room for rear-connected busbars or a cable duct behind the panel door. The 3 auxiliary switches HQ add no extra width — they stack on the side within the same pole footprint.