The Siemens SIRIUS 3RT2016-2MB42-0KT0 is a coupling contactor in the Size S00 footprint.
The coil is rated at 24 VDC nominal, with a pickup voltage of 0.85 × rated value (20.4 VDC) and a dropout voltage of 0.55 × rated value (13.2 VDC) — the full-scale dropout is 1.85 × the pickup threshold. This gives a clear operating band: the contactor pulls in reliably above 20.4 V and drops out below 13.2 V, which matters when sizing control transformers or dealing with voltage sag on a long DC run.
The main contacts are rated for 20 to 12 A (AC-3 duty, the standard for squirrel-cage motors). The contactor is designed for 750 operations per hour at AC-3 and AC-3e, and up to 1000 ops/h at AC-1 (resistive loads). At AC-4 (plugging/inching duty) the rate drops to 250 ops/h.
Auxiliary Contact Ratings (DC Switching)
This variant ships without an auxiliary switch block. If you need auxiliary contacts for status feedback or interlocking, they must be added separately. The DC switching ratings for the main contacts are relevant for DC load circuits: 10 A at 24 V, 2 A at 48 V and 60 V, 1 A at 110 V, 0.9 A at 125 V, 0.3 A at 220 V, and 3 A at 400 V. The arcing time at DC is 10 to 15 ms, with a DC operating time of 5 to 20 ms — useful for estimating contact wear in DC motor brake or solenoid circuits.
The contactor measures 45 mm wide × 70 mm high × 73 mm deep (Size S00). These clearances mean it fits tightly in a standard 600 mm wide enclosure with room for wiring ducts alongside.