CLASS 10 trip and S0 frame — what the ratings mean
The 3RA2120-1GA24-0AP0 is a Siemens SIRIUS direct-on-line starter in the S0 load feeder size, rated for AC-3 switching duty up to 690 V. The CLASS 10 trip characteristic means the overload relay will open within 10 seconds at 600% of the set current — this is the standard protection for standard squirrel-cage motors starting under load, where the inrush transient needs to ride through without nuisance tripping. The starter ships as a pre-assembled unit: a 3RT2024-1AP00 contactor and a 3RA2921-1AA00 link module, mounted on a common base. Clearance requirements: 50 mm above, 20 mm forward, 10 mm below, 20 mm to the side, zero backward. These matter for heat dissipation and for the arc chamber to vent properly during a fault — pack them tighter and the thermal derating curve shifts.
Mounting and panel integration
Screw and snap-on mounting onto 35 mm DIN rail — the snap-on foot is the faster option for production builds; the screw mount is for vibration-prone locations where the DIN latch could walk loose over time. Vertical orientation is mandatory; horizontal mounting changes the thermal behaviour of the bimetal overload. Main circuit connections are screw-type terminals, sized for the S0 frame current. The control circuit voltage is 230 V AC at 50 Hz — confirm the coil rating matches the control transformer tap before wiring. Operating temperature range is -20 to +60 °C, storage and transport -50 to +80 °C. If the panel ambient exceeds 60 °C, the overload relay must be derated or a separate thermal management solution added.
Lifecycle and sourcing — current production, quoted to order
Sourced through authorized distribution channels against an RFQ. This is not a surplus or broker-channel part; it carries full manufacturer traceability and warranty.