The Siemens 3VA1125-5EF36-0JA0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection in commercial and industrial distribution panels. It is a 3-pole unit rated 25 A continuous at 40 °C, with a TM240 thermal-magnetic overcurrent release and an integrated shunt trip (STL) for remote tripping. The interrupting rating hits 187 kA at 240 V AC — that is the figure that governs fault-clearing capability in low-voltage switchgear, not the higher-voltage numbers.
Interrupting and continuous ratings
This MCCB carries a 25 A continuous rating from 40 °C through 50 °C, then derates to 24 A at 55–60 °C and 23 A at 65–70 °C. That means in a warm enclosure — say a panel running 55 °C — you lose 1 A of headroom; plan the load accordingly. The interrupting capacity is 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 500 V and 690 V. The 187 kA figure at 240 V is what you use for SCCR coordination on a 240 V delta or 277/480 V wye secondary side; the 121 kA at 415 V covers most 400 V-class industrial feeds.
Release and auxiliary options
The TM240 release is a thermal-magnetic type — thermal element for overload protection, magnetic for short-circuit. The shunt trip (STL) allows a remote signal (e.g., from an emergency-stop relay or a PLC output) to open the breaker. No undervoltage release is fitted on this variant. The supplied basic switch is order code 3VA11255EF360AA0, which is the base MCCB without the shunt trip — so the -0JA0 suffix adds the STL as a factory-installed accessory. Rated insulation voltage is 800 V, which covers the full operating range up to 690 V with margin.
Physical fit and environment
Dimensions are 130 mm high, 76.2 mm wide, 70 mm deep. That is a standard 3-pole MCCB footprint for DIN-rail or panel-mount installation in a SENTRON distribution board. Operating temperature range is -25 °C to +70 °C; storage from -40 °C to +80 °C. Maximum power loss is 8.5 W — negligible for thermal budgeting in a ventilated enclosure, but worth noting if the panel is sealed and densely packed.