Siemens 3VA2140-6JQ32-0DH0 — 40 A MCCB with flat thermal derating to 70 °C
The Siemens SENTRON 3VA2140-6JQ32-0DH0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, carrying a full-scale value of 40 A and a minimum trip setting of 1.5 A. What sets this breaker apart for panel builders is its thermal performance: the 40 A rating holds flat from 40 °C all the way to 70 °C ambient — no derating curve to calculate for standard industrial enclosures. Breaking capacity reaches 242 kA at 240 V, stepping down to 187 kA at 415 V and 440 V, 121 kA at 500 V, and 3.7 kA at 690 V. That gives you headroom for high-fault installations without oversizing the frame.
Auxiliary and release configuration
This variant ships with 2 auxiliary switches plus 1 trip alarm switch (HQ designation) and an integrated undervoltage release (UVR). The UVR ensures the breaker trips on loss of control voltage — standard for emergency-stop chains or safety isolation where you need the load guaranteed off when the control supply drops. Communication function is built in, so it can report status to a higher-level system without an add-on module. A trip indicator is present for visual confirmation at the panel face.
Physical fit and panel integration
Dimensions are 105 mm wide, 181 mm high, and 86 mm deep — a standard SENTRON 3VA frame footprint that fits existing DIN-rail or panel-mount layouts without re-drilling. Maximum power loss is 4.1 W, which keeps internal enclosure temperature rise manageable even in a densely packed cabinet. Storage temperature range is -40 °C to 80 °C; operating range is -25 °C to 70 °C.