What this MCCB delivers
The Siemens 3VA2140-5JQ42-0AA0 is a 4-pole SENTRON molded case circuit breaker (MCCB) rated for 40 A continuous current, with an adjustable thermal-magnetic trip unit spanning 60 A minimum to 480 A maximum — meaning you set the actual protection point within that window to match the downstream load. Breaking capacity is 187 kA at 240 VAC, dropping to 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 3.7 kA at 690 V — the 240 V figure tells you this breaker handles high available fault current at lower voltages typical of North American distribution panels. Rated insulation voltage is 800 V, and the breaker carries a communication function for integration into higher-level monitoring or control schemes — not just a standalone overcurrent device. Ground-fault monitoring uses summation current formation on L+N conductors, so it detects leakage without a separate GFCI module.
Sizing and selectivity
The 40 A continuous rating holds flat from 40 °C through 70 °C ambient — no derating needed across that temperature band, which simplifies panel layout in warm enclosures. Maximum power loss is 1.6 W, low enough that adjacent devices see minimal heat rise in a crowded DIN-rail or panel-mount arrangement. The adjustable trip range (60–480 A) lets you coordinate with upstream and downstream devices for selective coordination — set the magnetic pickup above the inrush of downstream motor starters or downstream MCCBs.
Physical fit and environment
Dimensions are 86 mm deep, 140 mm wide, 181 mm high — the width is the critical panel cutout dimension; verify against existing busbar or mounting base spacing. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C — the storage limit governs handling and warehousing, not running conditions. Designed for line protection (not motor or generator protection), so the trip curve and time-delay characteristics are optimized for feeder and branch-circuit duty.