What ships in the carton
The Siemens SENTRON 3VA2125-6JP42-0AA0 is a 4-pole molded case circuit breaker (MCCB) rated 25 A continuous, fitted with the ETU550 electronic trip unit. Breaking capacity runs 242 kA at 240 V, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 3.7 kA at 690 V — so the same frame covers high-fault service-entrance duty and downstream distribution without a frame-size jump. Insulation voltage is rated 800 V. The front carries IP40 protection; the unit is 140 mm wide, 181 mm tall, 86 mm deep. Communication function is built in, and a motor-drive option is available as an extension.
Trip unit and protection profile
The ETU550 is an electronic overcurrent release — adjustable long-time, short-time, instantaneous, and ground-fault (though this unit ships without ground-fault monitoring). That means you can shape the trip curve to coordinate with downstream breakers and upstream transformers, not just rely on a fixed thermal-magnetic bimetal. The 25 A rating holds flat from 40 °C through 70 °C, so no derating curve to chase in a warm panel.
Panel fit and environment
At 140 mm wide × 181 mm tall × 86 mm deep, this 4-pole frame fits standard MCCB panel cutouts. Operating range is -25 °C to 70 °C; storage from -40 °C to 80 °C. Maximum power loss is 0.6 W — negligible for thermal budgeting inside a sealed enclosure.