The 48 V AC coil keeps control voltage in the low-voltage safety band, common in panel designs that separate power and control circuits.
The 9 A AC-3 rating is the motor-switching current — the figure that governs contactor life under inductive loads. For resistive loads (AC-1), the same contactor can switch a higher current, but the AC-3 number is the one to match against your motor's full-load amps. The 48 V AC coil draws from a control transformer or dedicated supply; verify the coil's pick-up and drop-out range against your control voltage stability — the contactor holds in at nominal but may chatter if the supply sags below about 40 V.
At 57 mm deep, 90 mm wide, and 58 mm tall, the LC8K0910E7 fits a standard 90 mm DIN-rail pitch. The preassembled reversing busbar adds no extra width over a single contactor footprint — the reversing pair occupies the same 90 mm slot as two side-by-side contactors would. Panel builders can plan for one 90 mm wide position per reversing pair, which simplifies DIN-rail layout and terminal numbering.