What this MCCB delivers
The Siemens 3VA1020-4ED32-0JA0 is a SENTRON molded case circuit breaker (MCCB) rated for line protection, carrying 20 A continuous at 40 °C through all three poles. Its interrupting capacity hits 121 kA at 240 V AC — enough to clear high-fault industrial feeders without cascading upstream. The TM210 thermal-magnetic release handles overload and short-circuit curves; the integrated shunt trip (STL) lets a remote signal or safety relay drop the breaker on demand.
Interrupting capacity across voltages
This breaker's short-circuit rating is voltage-dependent — a key detail when the panel feeds multiple bus voltages. At 240 V it clears 121 kA; at 415 V that drops to 75.6 kA; at 440 V it's 52.5 kA; at 500 V and 690 V it holds at 11.9 kA. That 11.9 kA floor at 690 V still covers most motor-drive branch circuits. The insulation voltage is rated 800 V, so the breaker itself is built for 690 V systems.
Thermal derating and power loss
Rated current is 20 A from 40 °C up through 55 °C, then derates to 19 A at 60 °C and 65 °C, and stays at 19 A at 70 °C. That's a shallow derating curve — useful in a crowded enclosure where ambient runs warm. Maximum power loss is 12 W, which matters for heat buildup in a sealed panel.
Panel fit and wiring
The 3VA1020-4ED32-0JA0 measures 130 mm tall, 76.2 mm wide, and 70 mm deep. That 70 mm depth is shallow enough for most 200 mm deep enclosures without crowding the gland plate. Three-pole construction; the shunt trip (STL) requires a separate control voltage — no undervoltage release here, so verify the trip coil wiring if replacing a UVR-specified breaker.