What this MCCB is and what it does
The Siemens SENTRON 3VA1040-3ED36-0DC0 is a 3-pole molded case circuit breaker (MCCB) rated for 40 A continuous current across the 40 °C to 50 °C ambient band, with a slight derating curve starting at 55 °C (38.4 A) down to 36 A at 70 °C. It is designed for line protection — meaning it sits at the feeder or branch point to protect cables and buswork from overloads and short circuits, not as a motor-protective device with integrated overload class. The interrupting capacity tells you where this breaker can safely clear a fault: 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 7.5 kA at both 500 V and 690 V. That 75.6 kA at 240 V is a high-fault rating — suitable for main or subfeed positions on a large industrial panel where available fault current is substantial. The drop at higher voltages is typical for a compact MCCB frame; if your system runs at 690 V, verify the 7.5 kA SCCR is adequate for your upstream transformer.
Built-in auxiliary and undervoltage release
This variant ships with two auxiliary switches (HQ type) and an undervoltage release (UVR) factory-installed. The UVR trips the breaker when control voltage drops below a threshold — common in emergency-stop chains or undervoltage protection schemes where a loss of control power must open the main breaker. The two auxiliary switches provide status feedback (open/closed/tripped) to a PLC or indication lamp. No ground-fault monitoring is included on this version.
Physical fit and panel integration
Dimensions: 130 mm height, 76.2 mm width, 70 mm depth. The 3VA frame mounts on a DIN rail or can be screw-mounted to a backplate. The 76.2 mm width (3 inches) is a standard 3-pole MCCB footprint — it occupies three 25.4 mm module positions on a DIN rail. Rated insulation voltage is 800 V, and the maximum power loss at rated current is 13.3 W — factor that into enclosure thermal calculations if the panel is densely populated.
Environmental limits
Operating temperature range: -25 °C to +70 °C. Storage range: -40 °C to +80 °C. The storage limits exceed the operating range, which governs handling and warehousing, not running conditions.