The Siemens SENTRON 3VA1140-3EF36-0DA0 is a 3-pole molded case circuit breaker (MCCB) rated 40 A at 40 °C, with a TM240 thermal-magnetic overcurrent release. It carries a breaking capacity of 75.6 kA at 240 V AC, derating to 52.5 kA at 415 V and 11.9 kA at 690 V. Built for line protection in distribution panels, it includes an undervoltage release (UVR) as standard — no trip indicator, no ground-fault monitoring, no communication module.
Breaking capacity across voltage levels
This MCCB's interrupting rating is voltage-dependent: 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 11.9 kA at both 500 V and 690 V. For a 400 V distribution board, the 52.5 kA figure is the one that governs fault clearance — enough for most industrial main feeders. At 690 V the 11.9 kA rating still covers typical motor-circuit fault levels in heavy drive applications.
Current rating and thermal derating
Rated 40 A continuously at ambient temperatures from 40 °C through 50 °C. Above that, derating is gradual: 39 A at 55 °C and 60 °C, 38 A at 65 °C, 37 A at 70 °C. The operating ambient range is -25 °C to 70 °C, with storage from -40 °C to 80 °C. In a hot mill environment near the rolls, the 70 °C ceiling means the breaker can sit inside a ventilated enclosure without forced cooling — it takes the radiant heat.
Undervoltage release and auxiliary options
The UVR (undervoltage release) trips the breaker when line voltage drops below a threshold — standard on this variant for safety circuits where loss of control power must open the main contacts. No communication function, no ground-fault module, no trip indicator. The design is line protection, not motor protection; the TM240 thermal-magnetic release handles overload and short-circuit within the same package.
Dimensions and panel fit
Footprint: 76.2 mm wide (3 in), 130 mm tall (5.12 in), 70 mm deep (2.76 in). Three-pole block mounts on a DIN rail or direct-panel bolted. The 70 mm depth leaves clearance for rear-connected busbars in a standard 200 mm deep enclosure. Max power loss at rated load is 13.3 W — modest heat rejection for a 40 A frame, but account for it in a sealed cabinet with other breakers.