What this 3VA2 MCCB is and what it does
The Siemens SENTRON 3VA2225-5KP32-0BC0 is a 3-pole molded case circuit breaker (MCCB) rated for 250 A continuous current, designed for line protection in distribution panels. It carries an interrupting capacity of 187 kA at 240 V AC, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 4.5 kA at 690 V — so the available fault current at the installation point determines which voltage rating governs the selection. A built-in communication function and other measurement function (per the datasheet) allow this breaker to report status and measured values over a network, which is useful for remote monitoring in a plant-floor power distribution scheme.
Thermal derating and ambient conditions
The continuous current rating holds at 250 A from 40 °C through 50 °C ambient. Above that, it derates linearly: 238 A at 55 °C, 225 A at 60 °C, 213 A at 65 °C, and 200 A at 70 °C. If the panel ambient runs above 50 °C, the actual load current must be reduced per this curve — the breaker does not carry its full 250 A nameplate at elevated temperatures. 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.
Auxiliaries and releases
This variant includes an undervoltage release (UVR) and two auxiliary switches (HQ design). The UVR trips the breaker when control voltage drops below a threshold — common in safety circuits or emergency-stop chains where loss of control power must open the main contacts. Maximum power loss is 50.5 W at rated current — relevant for enclosure thermal calculations if multiple breakers are ganged in a small cabinet.
Physical fit and panel integration
Dimensions are 105 mm wide, 181 mm high, 86 mm deep. The 105 mm width is a 3-pole frame size — verify the panel cutout or mounting base matches before specifying. No trip indicator or voltage trigger on this variant.