MCCB for line protection — 20 A, 121 kA interrupting
The Siemens 3VA1020-4ED36-0JA0 is a SENTRON molded case circuit breaker (MCCB) for line protection, rated 20 A continuous at 40 °C with a 3-pole configuration. Its interrupting capacity hits 121 kA at 240 V, tapering to 75.6 kA at 415 V and 52.5 kA at 440 V — that's the short-circuit current it can safely clear without welding contacts or rupturing the case. The TM210 thermal-magnetic release handles overload and short-circuit protection in one unit. This breaker includes a shunt trip release (STL) for remote tripping via a control voltage — useful for emergency-stop circuits or interlocking schemes where you need to drop the load from a PLC or safety relay. No undervoltage release, no ground-fault monitoring, no communication module; it's a straightforward line-protection MCCB with a single auxiliary function.
Footprint and panel fit
Dimensions are 70 mm deep, 76.2 mm wide, 130 mm tall — that's a compact 3-pole MCCB that fits standard SENTRON mounting bases and busbar systems. The 76.2 mm width is 3 inches, matching the common 3-pole MCCB footprint for retrofit into existing Siemens or compatible panels. No trip indicator on the front face; the shunt trip adds a secondary terminal block for the control wiring.
Thermal derating and operating range
Rated current holds at 20 A from 40 °C through 55 °C, then derates to 19 A at 60–70 °C. That's a generous thermal margin — most MCCBs start derating at 40 °C. Operating ambient spans -25 °C to 70 °C, storage from -40 °C to 80 °C. Insulation voltage rated 800 V, so it's fine on 480/600 V systems with headroom.