The Siemens SENTRON 3VA1020-3ED36-0CC0 is a 3-pole molded case circuit breaker (MCCB) rated for 20 A at 40 °C, with a breaking capacity of 75.6 kA at 240 V AC. It's designed for line protection in distribution panels — the kind of duty where you need a clean trip curve and a reliable undervoltage release (UVR) to drop the load when control voltage disappears.
Breaking capacity and thermal derating
Breaking capacity drops as voltage climbs: 52.5 kA at 415 V, 32 kA at 440 V, and 7.5 kA at both 500 V and 690 V. That's a steep derate above 440 V — verify your system's available fault current at the point of installation before committing this breaker to a 480 V or 600 V panel. Thermal rating holds steady at 20 A from 40 °C through 55 °C, then drops to 19 A at 60 °C and 65 °C, and stays at 19 A through 70 °C. No derate below 55 °C simplifies panel sizing in most industrial environments — you don't lose headroom until the ambient pushes past that mark.
Undervoltage release and auxiliary switches
This MCCB ships with an undervoltage release (UVR) fitted — the design of the auxiliary release is undervoltage release (UVR), per the spec. That means the breaker trips when control voltage drops below a threshold, which is standard for safety circuits where a loss of control power should open the main contacts. It also carries two auxiliary switches (HQ design) for status feedback back to the PLC or annunciator.
Physical fit and panel integration
Dimensions: 130 mm height, 76.2 mm width, 70 mm depth. That's a standard SENTRON 3VA1 footprint — mounts on a DIN rail or directly to a mounting plate via the screw terminals. The 70 mm depth (2.76 in) is shallow enough for most 200 mm deep enclosures without crowding the wiring gutter.