Siemens 3VA1020-3ED32-0HH0 — SENTRON MCCB, Line Protection, 20 A
The Siemens 3VA1020-3ED32-0HH0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection in distribution panels. It carries a rated current of 20 A at 40 °C, with a 3-pole configuration and an interrupting capacity of 75.6 kA at 240 V — enough to handle high-fault utility feeds or transformer secondaries without cascading upstream. The 800 V rated insulation voltage and 12 W maximum power loss are the numbers that govern panel thermal design and busbar spacing.
Interrupting Capacity and Selectivity
The interrupting capacity varies with system voltage: 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 7.5 kA at both 500 V and 690 V (–). For a site electrical engineer coordinating with an upstream feeder, the 52.5 kA at 415 V is the figure that determines selectivity with a larger-frame MCCB or air circuit breaker. At 690 V the 7.5 kA limit means this breaker is only suitable for low-fault sub-distribution in 690 V systems — not for main service entrance duty.
Thermal Derating and Panel Fit
The 20 A rating holds from 40 °C through 55 °C; at 60 °C it derates to 19 A, and at 70 °C it stays at 19 A (–). For a panel builder in a non-climate-controlled enclosure, this means the breaker delivers its full 20 A up to 55 °C ambient — no headroom lost until the panel hits 60 °C. The dimensions — 70 mm depth, 76.2 mm width, 130 mm height (–) — fit a standard 3-pole MCCB footprint on DIN rail or direct panel mounting. The auxiliary switch configuration includes 2 auxiliary switches plus 1 trip alarm switch HQ, and a shunt trip (STL) release is built in, which simplifies remote tripping for emergency-stop circuits.