Siemens SENTRON 3VA2125-7KQ36-0AA0 — 25 A MCCB with 330 kA Breaking Capacity
The Siemens 3VA2125-7KQ36-0AA0 is a SENTRON molded case circuit breaker (MCCB) rated for 25 A continuous current in a 3-pole configuration, designed for line protection in industrial distribution panels. Its headline breaking capacity reaches 330 kA at 240 VAC, dropping to 242 kA at 415 V and 440 V, 187 kA at 500 V, and 3.7 kA at 690 V — meaning it can safely interrupt fault currents up to those levels without cascading upstream, critical for high-fault installations like transformer secondaries or large motor control centers. The 25 A rating holds flat across ambient temperatures from 40 °C to 70 °C, so no derating is needed in a warm panel — a practical advantage when the breaker sits near other heat sources.
Selectivity and Coordination
With a minimum trip setting of 38 A and maximum of 300 A, this MCCB offers a wide adjustment range for coordinating with downstream branch breakers — useful for achieving selective coordination in a multi-level distribution scheme where you want only the faulted branch to open. The 800 V rated insulation voltage gives headroom for 690 V systems, and the 0.6 W maximum power loss keeps heat dissipation low in a crowded enclosure.
Integration and Mounting
The breaker measures 105 mm wide, 181 mm high, and 86 mm deep — a standard 3-pole MCCB footprint that fits most DIN-rail or panel-mount enclosures without requiring a custom gland plate or busbar rework. A communication function and other measurement function are built in, along with summation-current ground-fault monitoring on the L-conductor — so this unit can report status and fault data to a higher-level control system without an external module.