40 A, Curve B, 1-Pole — DIN-Rail MCB
It provides thermal-magnetic overload and short-circuit protection for branch circuits up to 40 A, with a 50 kA interrupting rating at 230 V AC — enough to handle high-fault-current industrial panels without cascading upstream.
What Curve B Means for Your Circuit
Trip Curve B means the magnetic trip fires at 3 to 5 times the rated current (120–200 A for this 40 A breaker). It will not nuisance-trip on a motor start the way a B-curve would, but for a 40 A branch feeding a panel of contactors and relays, B-curve is the standard choice.
Single-pole width saves space in a crowded enclosure — one module width. Rated for 400/690 V AC and 125 V DC operation at 50/60 Hz, so it can be used in mixed AC/DC control circuits as long as the voltage stays within the DC rating.