What this MCCB carries and what it protects
The Siemens 3VA1020-3ED36-0JH0 is a 3-pole SENTRON molded case circuit breaker rated 20 A continuous at 40 °C, with a breaking capacity of 75.6 kA at 240 V AC. It is designed for line protection — not motor protection — so it goes upstream of the contactor or downstream of the main disconnect in a distribution panel. The 70 mm depth and 76.2 mm width mean it fits a standard MCCB mounting footprint without crowding the adjacent poles.
Breaking capacity by voltage — where it clears
This breaker's interrupting rating drops as system voltage climbs: 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. For a 480 V panel downstream of a transformer, the 32 kA at 440 V is the closest reference — verify the available fault current at the point of installation. The 7.5 kA at 690 V is a hard ceiling; do not apply where prospective short-circuit exceeds that.
Thermal derating — the real continuous current
Rated 20 A from 40 °C through 55 °C ambient. At 60 °C it drops to 19 A, and holds there through 70 °C. In a packed enclosure with internal temperature rise, plan for the 19 A ceiling if the panel ambient exceeds 55 °C. The rated insulation voltage is 800 V, so the breaker itself handles the voltage stress; the limitation is purely thermal.
Auxiliary contacts and shunt trip included
Factory-fitted with two auxiliary switches plus a trip alarm switch (HQ configuration), and a shunt trip release (STL) for remote opening. The shunt trip lets a safety PLC or E-stop circuit drop the breaker without a manual reset cycle. No undervoltage release, no ground-fault monitoring, no communication module on this variant.