Siemens 3RT1015-1HB42-ZW96 — AC-3 Contactor, 24 VDC Coil, Size S00
The Siemens 3RT1015-1HB42-ZW96 is a 3-pole contactor in the SIRIUS series, size S00 frame, rated for AC-3 duty at 3 kW at 400 V. The DC 24 V coil accepts a control voltage range of 0.7 to 1.25 times the rated coil voltage (US), giving it a hold range from roughly 16.8 V to 30 V DC — useful for applications with a sagging 24 V bus or long cable runs. The built-in 1 NC auxiliary contact is wired for status feedback or interlocking without an extra side-mount block. The screw terminals accept standard ferrule or solid conductors up to the rated cross-section for this frame class. Multi-unit packing of 90 items (arranged 2×2 layers) is the factory packaging for this suffix variant — the ZW96 code flags the bulk pack, not the standard single-unit box.
AC-3 Motor Rating and Coil Tolerance
The AC-3 rating of 3 kW at 400 V defines the contactor's capability for switching squirrel-cage motors — making and breaking currents during starting and stopping under load. At 400 V three-phase, that covers motors up to roughly 7 A full-load current. The 1 NC auxiliary is rated for the same utilization category; wire it as a mirror contact for PLC feedback or as a mechanical interlock in a reversing pair. The 24 VDC coil's 0.7...1.25*US tolerance means the contactor picks up reliably at 16.8 V and stays sealed up to 30 V. This is wider than the standard ±10% many DC coils specify, so it handles a 24 V battery-backed supply that drifts low under load or a lightly regulated power supply that runs high. No built-in suppression — add a free-wheel diode across the coil if the DC supply drives other inductive loads.