The Siemens 3RT1926-2CG21 is a SIRIUS timing relay for ON-delay switching. The delay is adjustable from 0.5 to 10 seconds. It is a slow-operating device. The control supply accepts 24 … 66 V AC at both 50 Hz and 60 Hz, or 90 … 240 V DC. That dual-range AC/DC input means it can be wired into either a standard 24 V control transformer circuit or a higher-voltage DC bus without needing a separate power supply module.
Clip-on fastening to a DIN rail — standard 35 mm rail. The relay body is 45 mm wide, 26 mm tall, and 50 mm deep. That 45 mm width is a single modular unit, so it occupies one slot on the rail. Wire termination accepts solid or stranded conductors 18 … 14 AWG, or two 20 … 14 AWG solid wires in parallel. The spring-cage terminals (implied by the clip-on design and typical SIRIUS practice) hold the wire without needing a screwdriver torque check — strip length around 8 mm is typical for this class.
Environmental and operating limits
Pollution degree 3 (industrial environment with conductive or dry non-conductive pollution). Basic insulation type — suitable for ungrounded control circuits where the relay is not the primary safety isolation barrier.