What it is and what it does
The Siemens SENTRON 3VA2140-7JQ36-0AA0 is a 3-pole molded case circuit breaker (MCCB) rated for 40 A continuous current, with a maximum frame rating of 480 A and a minimum setting of 60 A. It's designed for line protection in distribution panels, with a communication function for integration into monitored systems.
Breaking capacity — the real-world fault handling
This MCCB delivers 330 kA breaking capacity at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 3.7 kA at 690 V. Those numbers tell you it can safely interrupt high fault currents typical in industrial distribution — the 330 kA at 240 V covers large transformer secondaries and busway feeds. The steep drop to 3.7 kA at 690 V means it's not intended for 690 V main service; that's a coordination point for the panel designer.
Thermal performance and derating
The breaker holds its 40 A rating continuously from 40 °C up to 70 °C ambient — no derating needed across that range. That's useful in a crowded panel where internal temperatures run high. Rated insulation voltage is 800 V, and the maximum power loss is 1.6 W, which is low enough to ignore for thermal budgeting in most enclosures.
Mounting and integration
The 3VA2140-7JQ36-0AA0 measures 105 mm wide, 181 mm high, and 86 mm deep — a standard MCCB footprint that fits most DIN-rail or panel-mount enclosures without surprises. The 3-pole block lands on a 105 mm wide busbar or lug kit, and the communication function means it can report status to a higher-level control system.
Ground-fault and monitoring
This variant includes summation-current ground-fault monitoring on the line conductors — it measures the vector sum of the phase currents to detect leakage to earth. No undervoltage release or voltage trigger is fitted, and there's no trip indicator. The trip unit is set for line protection, not motor or generator protection.