The Siemens SENTRON 3VA1112-5MH36-0CH0 is a 3-pole molded case circuit breaker (MCCB) rated for 125 A continuous current, with a TM120M thermal-magnetic overcurrent release and an undervoltage release (UVR) factory-fitted. It's the starter-protection variant of the 3VA series — meaning it's sized for motor branch circuits where you need coordinated overload and short-circuit protection in one package.
Interrupting capacity and what it means for your panel
The interrupting capacity is the headline number that determines whether this breaker clears a fault without welding contacts or venting gas. At 240 V it's rated 187 kA, at 415 V it's 121 kA, at 440 V it's 75.6 kA, and at 690 V it drops to 8.5 kA. For a 125 A frame, those are high-interrupting figures — enough for most industrial service-entrance or main-switchboard positions where available fault current is high. The 690 V rating is lower, so if you're on a 690 V delta system, verify the SCCR at that voltage against your transformer's nameplate.
Rated current and thermal derating
The rated continuous current Iu is 125 A, and it holds that rating from 40 °C up to 50 °C ambient. Above 50 °C it derates gradually: 122 A at 55 °C, 120 A at 60 °C, 117 A at 65 °C, and 114 A at 70 °C. If your panel ambient runs above 50 °C — say, in a non-ventilated enclosure near a furnace line — size the load to the derated figure, not the nameplate 125 A. The rated insulation voltage is 800 V, so the breaker's internal clearance and creepage are fine for 480/600 V class systems.
Auxiliary contacts and undervoltage release
This breaker ships with an auxiliary contact configuration of 2 auxiliary switches plus 1 trip alarm switch (HQ designation). That's enough for a remote status indication — open/closed plus a separate trip signal — without adding an external contact block. The undervoltage release (UVR) is factory-installed; it trips the breaker when control voltage drops below a threshold, which is standard for safety circuits where a loss of control power must open the motor circuit. The integrated auxiliary trip is order code 3VA9608-0BB24, in case you need to replace it separately.
DIN-rail footprint and panel fit
The 3VA1112-5MH36-0CH0 measures 130 mm high, 76.2 mm wide (3-pole), and 70 mm deep.