Interrupting capacity and selectivity
The 3VA1020-4ED36-0AF0: At 240 V the 121 kA SCCR lets this MCCB sit upstream of downstream breakers without cascading failure, provided the let-through energy is coordinated. The 800 V rated insulation voltage (Ui) supports use in 480/277 V and 600 V panels with adequate clearance. The 12 W maximum power loss at rated load matters for enclosure thermal rise — a sealed stainless enclosure may need derating or forced ventilation above 40 °C ambient.
Thermal derating and ambient range
The breaker holds 20 A from 40 °C through 55 °C, then derates to 19 A at 60 °C and 65 °C, and stays at 19 A through 70 °C. Operating ambient spans -25 °C to +70 °C; storage range is -40 °C to +80 °C. The TM210 release is fixed thermal-magnetic — no electronic adjustment, which simplifies spares but limits field tweaking.
Auxiliary and alarm contacts
Factory-fitted with 1 auxiliary switch and 1 trip alarm switch (HQ design). The trip alarm signals on overcurrent or short-circuit trip — useful for remote fault annunciation on a PLC DI. No undervoltage release, no ground-fault monitoring, no communication module on this variant.
Dimensions and panel fit
Footprint is 76.2 mm wide (3 in), 130 mm tall (5.12 in), 70 mm deep (2.76 in). Standard 3-pole MCCB spacing — mounts on a DIN rail or panel-mount base. The 70 mm depth includes the handle throw; allow clearance for arc-chamber venting per Siemens mounting instructions.