630 A MCCB with ETU850 — what the ratings mean for panel fit
The Siemens 3VA2463-5KP32-0JH0 is a 3-pole SENTRON molded case circuit breaker rated for 630 A continuous current (Iu) at 40 °C, with an ETU850 electronic trip unit for line protection. Breaking capacity runs 187 kA at 240 V AC, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 17 kA at 690 V — so the interrupting rating drops sharply above 500 V; verify the available fault current at your system voltage before committing the BOM line. The 630 A rating is at 40 °C ambient; derate to 450 A at 70 °C if the panel runs hot. Maximum power loss is 162 W — account for that heat in the enclosure ventilation calculation.
Temperature derating and enclosure planning
Rated continuous current drops from 630 A at 40 °C to 600 A at 45 °C, 570 A at 50 °C, 540 A at 55 °C, 510 A at 60 °C, 480 A at 65 °C, and 450 A at 70 °C. If the breaker sits in a crowded panel or near other heat sources, size the buswork and downstream components for the derated figure at your actual ambient — not the 40 °C headline. Operating temperature range is -25 °C to 70 °C; storage range -40 °C to 80 °C. Dimensions are 248 mm high, 138 mm wide, 110 mm deep — confirm the mounting footprint against the existing switchgear cutout or DIN-rail adapter plate.
Trip unit, auxiliaries, and release options
The ETU850 overcurrent release provides electronic protection with adjustable pickup and time-delay settings for long-time, short-time, instantaneous, and ground-fault (though this variant ships without ground-fault monitoring). A shunt trip (STL) design of the auxiliary release is fitted — order code 3VA9688-0BL32 for the integrated auxiliary trip, and 3VA2463-5KP32-0AA0 for the supplied basic switch. The auxiliary contact configuration is 2 auxiliary switches plus 1 trip alarm switch (HQ version). A voltage trigger is present, and a communication function is included for integration into a higher-level monitoring system. No undervoltage release or phase failure detection on this variant.