MCCB with undervoltage release for line protection
The Siemens SENTRON 3VA1180-3EF32-0CA0 is a 3-pole molded case circuit breaker (MCCB) rated for line-protection duty. It carries 80 A continuously at 40 °C ambient, with minimal derating up to 70 °C — still delivering 74 A at the top end. The interrupting capacity is 75.6 kA at 240 V, dropping to 52.5 kA at 415 V and 11.9 kA at 690 V, so it handles high-fault scenarios on 400 V-class distribution panels. An integrated undervoltage release (UVR) is fitted as standard, which trips the breaker when control voltage drops — typical for emergency-stop or safety interlock circuits.
Sizing and thermal performance
Rated current holds flat at 80 A 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, and 74 A at 70 °C. For a panel running warm — say 55 °C internal ambient — you lose only 2 A off the nameplate. The TM240 thermal-magnetic release is fixed inside, meaning the thermal pickup and magnetic trip thresholds are factory-set. No field adjustment on the trip curve. Rated insulation voltage is 800 V, which covers 480 V and 600 V class systems with headroom.
Physical fit and panel integration
The breaker measures 76.2 mm wide, 130 mm tall, and 70 mm deep. That 70 mm depth is the key dimension when checking gland-plate clearance or enclosure depth — it fits standard 3-pole MCCB footprints in most distribution boards. No communication module, no ground-fault monitoring, and no trip indicator on this variant. It is a straight line-protection device with the undervoltage release as the only auxiliary release.