What this MCCB is and where it fits
The Siemens SENTRON 3VA1120-6EF36-0AH0 is a 3-pole molded case circuit breaker (MCCB) rated 20 A at 40 °C, designed for line protection in distribution panels and industrial switchboards. It carries a TM240 thermal-magnetic release — the thermal element handles overloads, the magnetic element clears short-circuits — and delivers a 220 kA interrupting capacity at 240 V, dropping to 154 kA at 415 V and 121 kA at 440 V. At 500 V and 690 V the rating holds at 17 kA. The 800 V rated insulation voltage (Ui) means it can be used in 480 V and 600 V class systems without derating the insulation. It mounts on a DIN rail or panel base, occupying 76.2 mm width, 130 mm height, and 70 mm depth — a standard 3-pole MCCB footprint that fits existing SENTRON panel layouts.
What the ratings mean for your panel
The 20 A rating is continuous at ambient temperatures up to 55 °C; at 60 °C and 65 °C it derates to 19 A, and at 70 °C it holds at 19 A. That means in a warm enclosure — say a non-ventilated panel near a motor drive — you still get 19 A of continuous current. The 220 kA SCCR at 240 V is the short-circuit current the breaker can safely interrupt without welding contacts or rupturing the case. In a 480 V system the 121 kA at 440 V applies; if your available fault current exceeds that, you need a current-limiting upstream device or a higher-rated frame. The TM240 release is adjustable — the thermal pickup and magnetic trip thresholds are set at the factory but can be field-adjusted within the release's range. The breaker includes a trip indicator and comes with 2 auxiliary switches plus 1 trip alarm switch (HQ) built in, so you get status feedback without adding external modules. Maximum power loss is 12 W — negligible for thermal budgeting in most enclosures.
Integration and compliance notes
Mounts on a DIN rail or panel base — the 76.2 mm width matches the standard 3-pole MCCB pitch, so it drops into existing SENTRON or third-party panel cutouts without re-drilling. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C, covering most indoor and sheltered outdoor installations. The breaker has no undervoltage release, no ground-fault monitoring, and no communication function — it is a straight line-protection device. For compliance, Siemens provides the usual documentation package: CE marking for the European market, UL/CSA listings for North America (standard for SENTRON 3VA), and RoHS/REACH declarations. Specific certification numbers are available on request.