What this contactor actually does
The Siemens 3RF2310-1AA45 is a SIRIUS single-phase solid-state contactor built to switch a resistive or slightly inductive AC load up to 10.5 A in AC-51 duty — the rating UL lists as 9.6 A under UL 508 reflects the more conservative North American test profile, so a panel built to the 10.5 A figure still has a sensible safety margin on a 9.6 A nameplate. Zero-point switching means the output thyristor pair turns on at the next voltage zero-cross and off at the next current zero — the 1 ms ON and OFF delay figures cited plus a maximum of one additional half-wave describe exactly that timing, which is what you want for resistive heater loads and transformer primaries where a hard turn-on mid-cycle would inject a damaging inrush or DC component. Control-side draw sits at 18 mA at DC rated, with the spec line also showing 20 mA DC and a 30 V DC control supply rating, so the unit is driven directly from a low-power DC source without an interposing relay.
Voltage window, thermal budget, and where it fits
Steady-state heat is 11 W in the hot operating state, so the 40 °C derating temperature and the –25 to +60 °C operating envelope (–55 to +80 °C storage) are the real thermal constraints when the unit is side-by-side mounted with its neighbours — stacked density matters more than ambient alone. The minimum operational current is 100 mA and the thyristor reverse (off-state) leakage is 10 mA, so very small heater loads or low-current resistive pilots below the 100 mA figure will sit with a residual 10 mA flowing even when the output is commanded off.
Mounting, wiring, and short-circuit coordination
Short-circuit coordination uses the I²t value of 200 A²·s paired with a 3NA6801 NH fuse or a 5SE2306 NEOZED fuse — both are listed as usable but carry a smaller rated current than the semiconductor, so the fuse is the over-current gate, not the relay.
Buying posture
Specified into the BOM by order code, the 3RF2310-1AA45 is sourced through independent distribution and quoted to order against the project quantity, with current pricing and availability confirmed once an RFQ is in hand — no factory-direct claim is being made here.