What this reversing contactor assembly is
The Siemens 3RA2327-8XB30-1AC2 is a SIRIUS reversing contactor assembly — two mechanically interlocked contactors in one package that let you reverse a three-phase motor without external interlocks. It ships with one 3RT2027-1AC20 contactor already supplied; the second contactor is the mirror half of the reversing pair.
Panel fit and mounting — size S0 constraints
The assembly is size S0: 101 mm high, 90 mm wide, 97 mm deep. That flexibility helps when you're squeezing it into a crowded panel. Clearance around the assembly: 6 mm upwards, forwards, downwards, and to the side, but 0 mm backwards (the back sits flat on the rail). That 97 mm depth plus 6 mm forward clearance means you need about 103 mm from the rail to the enclosure door or busbar.
Wiring and terminal specs — screw terminals, dual conductor capacity
That dual-conductor rating saves a terminal block when you need to loop through or parallel feed. The magnet coil also uses screw terminals — no push-in or spring-cage on the coil circuit. Keep that in mind if your shop standardizes on tool-less wiring.
Duty cycle and mechanical life — 10 million operations
Mechanical life is 10 million operations typical for the contactor. At AC-3 maximum switching rate of 750 operations per hour (also 750 for AC-3e), that's over 13,000 hours of continuous cycling at max rate before mechanical wear becomes a concern. Shock and vibration ratings: 13.5 g for 5 ms and 8.3 g for 10 ms on AC; 15 g for 5 ms and 10 g for 10 ms on DC. That's robust enough for most industrial environments short of direct hammer-mill mounting.