What it is and what it does
The Siemens 3VA1020-2ED36-0BH0 is a SENTRON 3VA1 molded case circuit breaker (MCCB) built for line protection in distribution panels. Rated 20 A continuous at 40 °C, it carries a solid 52.5 kA interrupting capacity at 240 V AC — enough to handle a stiff utility fault without upstream coordination headaches. The 800 V rated insulation voltage tells you it's comfortable in 480 V and 600 V class systems too.
Breaking capacity — where it matters
This MCCB delivers 52.5 kA at 240 V, 32 kA at 415 V, 13.6 kA at 440 V, and 7.5 kA at both 500 V and 690 V. That's a strong curve for a 20 A frame — the high 240 V number means it's a good fit for North American 120/240 V split-phase panels where available fault current can run high. At 690 V the 7.5 kA still covers most industrial motor branch circuits.
Thermal performance and panel fit
The 20 A rating holds steady from 40 °C up to 55 °C, then only drops to 19 A at 65 °C and 70 °C. That's a tight derating curve — you don't lose headroom in a warm enclosure. Dimensions are 130 mm tall, 76.2 mm wide, and 70 mm deep, which is the standard 3VA1 footprint. Fits a typical 3-pole MCCB slot on a DIN rail or panel-mount base.
Built-in auxiliaries and releases
This variant 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 a machine must isolate on power loss. The trip alarm switch gives a positive signal when the breaker trips on fault, not just manual open. Max power loss at rated load is 14.5 W, which is modest for a 3-pole 20 A MCCB with auxiliaries.