What it is and what it does
Siemens SENTRON 3VA1332-5GF42-0AA0 is a 4-pole molded case circuit breaker (MCCB) rated 320 A continuous, carrying a TM240 thermal-magnetic release. It's built for line protection — feeding a main bus, a distribution panel, or a large motor control center. The 320 A rating holds flat through 50 °C ambient; at 70 °C it still carries 292 A. That matters when the panel runs hot and you need the breaker to hold without nuisance tripping. Breaking capacity is the headline number that decides whether this breaker clears a fault without blowing up upstream. At 240 V it interrupts 187 kA — that's industrial-scale fault current, typical for transformer secondaries or large motor banks. At 415/440 V it still holds 121 kA. At 690 V it drops to 11.9 kA, so if you're on a 690 V system, confirm the available fault current is under that number. Insulation voltage is rated 800 V, so the breaker itself is insulated for 690 V line-to-line work.
Lifecycle and sourcing
The 3VA series is Siemens' current-generation MCCB platform. The TM240 release is a fixed thermal-magnetic trip — not electronic, not adjustable. If the BOM calls for a 320 A 4-pole with a fixed thermal-magnetic curve, this is a direct fit. No communication function, no ground-fault monitoring, no undervoltage release on this variant.
Panel fit and integration
Dimensions: 248 mm tall, 184 mm wide, 110 mm deep. That's a standard 4-pole MCCB footprint — mounts on a DIN rail or directly on a mounting plate. Front protection is IP40, meaning it's protected against tools and wires >1 mm, but not against water ingress. Keep it inside the enclosure, not on the door. Power loss at full load is 80.1 W. That's not trivial — if you're packing a dozen of these in a panel, factor that heat into the ventilation budget. Storage temperature range is -40 °C to 80 °C; operating range is -25 °C to 70 °C. The storage spec governs handling and shipping, not running.
What it doesn't have — and why that's fine
No trip indicator, no undervoltage release, no communication module, no ground-fault monitoring. This is a plain-vanilla line-protection MCCB. If you need adjustable trip curves or remote monitoring, look at the 3VA electronic-trip variants. But if the spec says '320 A, 4-pole, thermal-magnetic, line protection,' this is the exact part.