80 A MCCB with UVR — panel fit and interrupting capacity
The Siemens SENTRON 3VA1080-3ED36-0CH0 is a 3-pole molded case circuit breaker (MCCB) rated 80 A at 40 °C, designed for line protection in distribution panels. It carries a 75.6 kA interrupting rating at 240 V and 52.5 kA at 415 V — figures that govern its fault-clearing capability in low-voltage mains or feeder circuits. The 70 mm depth and 76.2 mm width (3 in) fit standard SENTRON mounting footprints; the 130 mm height clears most enclosure gutters without crowding. An undervoltage release (UVR) is built in, so the breaker trips when supply voltage drops below a set threshold — useful for motor circuits that must not auto-restart after a brownout. The auxiliary switch complement (2 aux + 1 trip alarm HQ) gives status feedback to a PLC or annunciator without an add-on module.
Thermal derating and power loss — what the numbers mean for panel loading
The 80 A rating holds from 40 °C through 50 °C ambient; above that it derates to 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 inside the enclosure — the breaker's effective continuous current is 78 A, not 80 A. Maximum power loss is 21.7 W, which feeds into the enclosure's thermal budget; a tightly packed cabinet needs that figure for the cooling calculation.
Interrupting capacity across voltages — where it fits in the fault-current map
The interrupting ratings step down with system voltage: 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 7.5 kA at both 500 V and 690 V (–). At a 480 V corner-grounded delta or a 400 V wye panel, the 52.5 kA figure at 415 V is the closest reference — sufficient for most industrial services with transformer impedances above 5%. The 800 V rated insulation voltage confirms suitability for 690 V systems where the breaker is applied.