What it is and what it does
The Siemens SIRIUS 3RT2524-2NF30-ZW96 is a 4-pole power contactor sized for switching three-phase motor loads up to 5.5 kW in AC-3 duty at 400 V. The AC-3 rating is what governs motor switching — it's the category for starting and stopping squirrel-cage motors under full load, so the 5.5 kW figure tells you the maximum motor size this contactor can handle in that application. With four main poles (2 NO + 2 NC) and an integrated auxiliary contact block (1 NO + 1 NC), it's built for applications that need both power switching and feedback in one package.
Coil and control
The coil accepts a universal AC voltage range of 95 to 130 V (UC designation means it's designed for AC control supplies). Inrush current peaks at 15 A for 30 µs during pickup — that's the initial surge to pull the armature in, and it's short enough that most PLC relay outputs driving an interposing relay can handle it. Once sealed, the holding current drops to 19 mA mean value, which keeps the coil dissipation low in a crowded panel. The locked-rotor current (what the coil draws if the armature fails to seat) is 0.19 A peak, 0.13 A mean, lasting 180 ms — the contactor's own control circuit should clear that before the coil overheats.
Panel fit and wiring
This is an S0 frame size contactor, which means it snaps onto a 35 mm DIN rail per EN 50022 and occupies a 45 mm width slot. The spring-loaded (cage-clamp) terminals on both main and auxiliary circuits accept solid or stranded copper from 0.5 to 2.5 mm² — no screw tightening, no torque check, just strip to 8 mm and push in. That saves time on a panel build and eliminates the risk of a loose screw vibrating out on a machine that cycles hard. The integrated auxiliary contacts (1 NO + 1 NC) are wired at the same terminals, so you don't need a separate auxiliary block for basic feedback.