Siemens 5TT5740-2 SENTRON Insta Contactor — 40 A, 4 NO, 24 V DC Coil
The coil is 24 V DC, making it compatible with standard 24 V DC control systems common in industrial panels.
Rated operating current of 40 A at both 230 V and 400 V AC — this is the thermal current (Ith) for the contactor, meaning it can carry 40 A continuously through the main poles in open air. The 3 000 W filament lamp switching capacity tells you it handles incandescent lighting loads with high inrush; for LED or fluorescent ballasts, derate per the manufacturer's guidelines. The 3 width units (each 18 mm) give a 54 mm wide footprint on the DIN rail, so it occupies three standard modular positions in a distribution board.
Overall dimensions: 90 mm high, 54 mm wide, 71 mm deep, with an installation depth of 64 mm behind the panel face. Four NO contacts give you four independent switching poles — useful for splitting a load across phases or for multi-circuit control.