What it is and what it does
The Siemens SIRIUS 3RT1016-1AP05-ZW95 is a size S00 power contactor from the SIRIUS family, designed for switching motor loads in industrial control panels. Its 24 VDC coil pulls in reliably, and the three main poles handle AC-3 duty up to 4.5 kW at 500 V and 5.5 kW at 690 V. The auxiliary contact block provides one normally-open and one normally-closed set rated at 10 A at 24 VDC. For the high-stress AC-4 switching regime — plugging or inching — the contactor is rated at 8.5 A at 400 V, which is the figure that governs repetitive reversing duty. The mechanical life of 30 million operations means the contactor will outlast most panel refreshes if the electrical load is kept within its AC-3 curve.
Mounting and integration
The 45 mm wide body snaps onto a 35 mm DIN rail per EN 50022, or can be screw-mounted. Side-by-side mounting is permitted with 6 mm spacing to adjacent devices, which keeps the panel layout tight. The screw-type terminals accept 2x (0.5 to 1.5 mm²) solid, 2x (0.75 to 2.5 mm²) stranded, or up to 1x 12 AWG — common wire sizes for motor starters in this frame class. IP20 on the front and at the terminals means the contactor is protected against finger contact but is not sealed against moisture — it belongs inside a panel with a minimum IP54 enclosure in wet environments. The pollution degree 3 rating confirms it is designed for the conductive dust and humidity typical of industrial control rooms.
Coordination and protection
For Type 2 coordination (no damage to the contactor after a short circuit), Siemens specifies a gL/gG fuse rated at 20 A. For Type 1 coordination (contactor may need replacement after a fault), the fuse rating goes up to 35 A. These values are for the main circuit and should be matched when designing the motor branch circuit. The operating temperature range of -25 to +60 °C covers most panel environments, but the coil hold-in voltage tolerance at 50 Hz is 0.8 to 1.1 times rated — at 60 Hz it tightens to 0.85 to 1.1. If your control transformer is marginal on voltage, the 60 Hz drop-out margin is narrower.