Siemens 3VA1020-3ED36-0HH0 — 20 A SENTRON MCCB for Line Protection
The Siemens 3VA1020-3ED36-0HH0 is a 3-pole SENTRON molded case circuit breaker (MCCB) rated for a continuous current Iu of 20 A, with a TM210 thermal-magnetic overcurrent release. It is configured for line protection — meaning its primary role is cable and busbar protection in a distribution panel, not motor or generator protection. The interrupting ratings are 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 7.5 kA at 690 V, which gives you the SCCR headroom for high-fault utility feeds or transformer secondaries. The thermal derating curve is flat from 40 °C to 50 °C at 20 A, then drops to 19.2 A at 55 °C, 18.8 A at 60 °C, 18.4 A at 65 °C, and 18 A at 70 °C. For a panel that runs warm near the top of a switchboard, you can still count on 18 A at 70 °C — no need to oversize a frame for ambient. The rated insulation voltage Ui is 800 V, so it is suitable for 690 V line-line systems common in mining or heavy industrial sites.
Auxiliary and Trip Configuration
This variant ships with 2 auxiliary switches plus 1 trip alarm switch (HQ type), and a shunt trip (STL) auxiliary release. The shunt trip allows remote tripping from a PLC or emergency-stop circuit — useful when the MCCB is in a remote panel and you need a hard-wired trip without a communication module. The integrated auxiliary trip order code is 3VA9688-0BL30, which is the factory-fitted accessory. There is no undervoltage release, no ground fault monitoring, no phase failure detection, and no communication function — this is a pure line-protection breaker with a remote trip capability.
Mechanical Endurance and Environmental Range
The latching endurance is rated at 15,000 operations — typical for a distribution MCCB that sees infrequent switching. The operating temperature range is -25 °C to 70 °C, with storage from -40 °C to 80 °C. Front protection is IP40, which means it is protected against tools and small wires entering from the front, but not against dust ingress from the sides — standard for panel-mounted breakers. Dimensions are 130 mm height, 76.2 mm width, and 70 mm depth, fitting the standard 3-pole SENTRON 3VA footprint.