The Siemens 3RT2926-2PA11-0MT0 is a SIRIUS pneumatic delay block designed to clip onto an S0-size contactor (3RT2.2 series) and provide an adjustable ON-delay of 1 to 60 seconds for one normally-open and one normally-closed auxiliary contact. It's a slow-operating, pneumatically-damped timer — no electronics inside, so it's inherently immune to voltage sags and harmonics that can scramble an electronic timer's count. The screw-type terminals accept 2x 0.5-1.5 mm² solid or 2x 0.75-2.5 mm² stranded, and the front is IP20 finger-safe.
Clip-on fastening means it snaps directly onto the front of a SIRIUS S0 contactor (3RT2.2) without tools, adding 45 mm width, 44.6 mm height, and 83.5 mm depth to the assembly. Mounting position is any orientation, so it fits in tight enclosures where you can't guarantee vertical.
Contact ratings and switching capacity
The delayed auxiliary contacts are rated for AC-12 duty up to 10 A, but the actual switching current depends on voltage: 4 A at 24 V, 2 A at 48 V, 0.7 A at 110 V, 0.3 A at 220 V, and 6 A at 230 V. At 400 V it handles 4 A, dropping to 0.1 A at 440 V, then 2.5 A at 500 V and 1.5 A at 690 V. These are the contact ratings for the delayed set — match your load voltage to the curve. Short-circuit protection requires a gG 10 A fuse rated for 1 kA per IEC 60947-5-1.
The substance prohibition date of October 1, 2009 indicates RoHS compliance per the EU directive.