The Schneider Electric LC1K120045E72 is a TeSys K contactor with 4 normally-open poles, rated 20 A in AC-1 utilisation category at 440 V — that's the resistive-load rating, so it handles heaters, lighting banks, or transformer primaries up to that current without derating. The coil pulls 48 V AC at 50/60 Hz, with an inrush of 30 VA and a hold-in draw of 4.5 VA at 20 °C, so the control transformer sizing is straightforward: the inrush spike is brief, and the sealed power is low enough that a standard 50 VA control transformer can run several of these. The 4-pole configuration (all NO) means this contactor switches four independent circuits simultaneously — useful for three-phase loads plus a neutral or a separate control signal.
The built-in bidirectional peak-limiting diode suppressor handles coil de-energisation transients, so you don't need an external flyback diode on the 48 V AC control circuit.
Performance and durability
Rated breaking capacity at 440 V is 110 A — five times the rated operational current, which gives solid fault-clearing headroom for resistive loads. The mechanical shock and vibration ratings are specified per IEC 60068-2-27 and -6: the contactor holds closed through 10 Gn on X and 15 Gn on Y/Z axes (11 ms half-sine), and survives 4 Gn vibration closed across 5–300 Hz. That's enough for most industrial machinery, including conveyors and compressors mounted near the source. Safety reliability is documented with B10d values: 1,369,863 cycles at nominal load and 20,000,000 cycles for mechanical-only load per EN/ISO 13849-1. The maximum operating rate is 3,600 cycles per hour — one per second — so it's fine for rapid cycling in packaging or sorting lines.