The Siemens SENTRON 3VA1020-4ED36-0BH0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, carrying 20 A continuously at 40 °C and derating to 19 A at 70 °C. Its interrupting capacity hits 121 kA at 240 V AC, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at both 500 V and 690 V — so the SCCR you need for a 480 V panel is well covered, and it still holds up on 690 V drives.
Ratings and what they mean for fit
The 20 A rating holds flat from 40 °C to 55 °C, then drops 1 A per 5 °C step to 19 A at 70 °C. That thermal curve means you can load it to nameplate in a warm enclosure without derating early — the headroom is built in. Rated insulation voltage is 800 V, so it's suitable for 690 V systems with margin. The breaker ships with an undervoltage release (UVR) and a complement of 2 auxiliary switches plus 1 trip alarm switch (HQ). The UVR means the breaker drops out on loss of control voltage — standard for safety circuits where you want fail-safe disconnection. No ground-fault monitoring is built in; that's handled externally if needed.
Panel fit and integration
Footprint is 76.2 mm wide, 130 mm tall, 70 mm deep — a standard 3-pole MCCB envelope that drops into most SENTRON or third-party distribution blocks without panel modifications. The 70 mm depth is the dimension you check against gland-plate clearance or shallow enclosures; it's shallower than many older-frame MCCBs, so retrofits into tight spaces are straightforward. Maximum power loss is 14.5 W — negligible for thermal budgeting in a populated panel, but worth noting if you're stacking multiple breakers in a sealed enclosure without forced ventilation.