What this 3-pole MCCB carries — the ratings that decide fit
The 3VA1125-5EF32-0CH0 is a Siemens SENTRON molded case circuit breaker (MCCB) built for line protection in distribution panels. Its headline interrupting capacity hits 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 690 V — the 240 V figure is the one that governs fault-clearing duty on low-voltage mains, while the 690 V rating confirms it handles industrial 600 V class systems where available fault current stays under 17 kA. Rated continuous current Iu is 25 A, flat from 40 °C to 50 °C, then derated stepwise: 24 A at 55 °C, 23.5 A at 60 °C, 23 A at 65 °C, 22.5 A at 70 °C. That thermal curve means an enclosure at 50 °C ambient still carries the full 25 A; push past 55 °C and you lose about 1 A per 5 °C rise. The overcurrent release is a TM240 — a thermal-magnetic design, fixed-trip, no electronic adjustability. That tells you this is a straight line-protection breaker for fixed loads, not a variable-trip feeder. It carries an undervoltage release (UVR) as the auxiliary release, so the breaker trips on loss of control voltage — common in emergency-stop chains or undervoltage protection schemes. The auxiliary contact block is a 2 aux + 1 trip alarm switch HQ variant, giving you two signal contacts plus a dedicated alarm contact that changes state on a fault trip. Rated insulation voltage Ui is 800 V, which covers 480/277 V and 600 V systems with margin. Front protection is IP40 — fine inside a closed panel, not for washdown zones.
Panel fit — dimensions and mounting
The 3VA1125-5EF32-0CH0 measures 130 mm high, 76.2 mm wide, 70 mm deep. That 76.2 mm width is a standard 3-pole MCCB footprint — three module-widths at roughly 25.4 mm per pole. It mounts to a DIN rail or direct-panel screw pattern typical of the SENTRON 3VA platform. The 70 mm depth means it clears a standard 200 mm deep enclosure without crowding the gland plate or busbar shroud. Verify the screw-terminal torque spec from the device manual before torquing to busbar or cable lugs.
Traceability and documentation
The auxiliary trip module specified for this unit is 3VA9608-0BB24 — that is the factory-matched undervoltage release module. The device manual (linked from Siemens Service & Support) covers DC network application notes if you are switching power values in DC circuits. For compliance documentation, Siemens provides RoHS and REACH declarations for the SENTRON 3VA series; UL and IEC listings are standard for MCCBs of this class — verify the specific UL file number against the nameplate on arrival.