SIRIUS S0 Power Contactor — 3 NO, 11 kW AC-2 at 400 V
The Siemens 3RT1026-1AV04 is a SIRIUS-brand power contactor in the S0 frame size, carrying three normally-open main contacts and no NC main contacts. It is rated for 11 kW at 400 V under AC-2 duty (slip-ring motor switching) and delivers 15.5 A at 400 V under AC-4 duty (plugging/reversing/inching). For motor starting (AC-3), the contactor also supports 11 kW at both 500 V and 690 V, giving headroom on higher-voltage distribution systems without stepping up frame size. The contactor mounts via screw fixing or snap-on onto 35 mm DIN rail per EN 50022, and side-by-side mounting is permitted — useful when packing multiple contactors into a single panel row.
Coordination & Protection
Type 2 coordination (no damage to the contactor under short-circuit) requires a 35 A gL/gG fuse upstream. Type 1 coordination (contactor may need replacement after fault) allows a 100 A gL/gG fuse. This gives the panel designer flexibility: use the 35 A fuse where uptime matters, or the 100 A where fault-clearing capacity is the priority. Pollution degree 3 rating means the contactor is suitable for industrial environments with conductive pollution or dry non-conductive pollution that becomes conductive due to condensation — standard for most control panels. Operating ambient temperature range is -25 to +60 °C, covering cold storage and hot panel interiors without derating at the lower end.
Termination & Wiring
Main circuit terminals are screw-type, accepting 2x (0.5...1.5 mm²), 2x (0.75...2.5 mm²), or max 2x (0.75...4 mm²) solid/stranded, with AWG equivalents 2x (16...12), 2x (14...10), or 1x 8. Auxiliary/control circuit terminals accept 2x (1...2.5 mm²) or 2x (2.5...6 mm²) solid/stranded, max 2x 10 mm², AWG 2x (20...16), 2x (18...14), or 1x 12. Front face carries IP20 finger-safe protection; the terminal area is IP00, so panel builders should maintain clearance or cover exposed live parts per the enclosure rating.