The LX9FF042 is a specific contactor coil from the TeSys F range, designed as a replacement or spare coil for TeSys F contactors. It is a low-consumption AC coil rated at 42 V AC, 40 to 400 Hz, without a built-in suppressor module. The coil draws an inrush power of 690 to 855 VA and holds at 6.6 to 8.1 VA at 68 °F (20 °C). Average resistance is 2.5 Ω inrush and 64.45 Ω holding at the same temperature. Closed-circuit inductance is 0.3 H. Operating time is 130 ms opening and 35 ms closing. Heat dissipation runs 5.9 to 7.2 W.
The part is obsolete. Any replacement must match the 42 V AC control voltage, low-consumption profile, and TeSys F mounting interface.
The 42 V AC control circuit voltage is the key fit parameter: this coil operates between 0.85 and 1.1 Uc and drops out between 0.2 and 0.55 Uc at 131 °F (55 °C). The 2400 cycles/hour maximum at 55 °C sets the thermal duty limit. In a high-speed pick-and-place or conveyor switching application, stay under that rate to avoid exceeding the 5.9 to 7.2 W heat dissipation capacity. The 10 Mcycle mechanical life means the coil itself is not the wear item in most installations — the contactor's main contacts will typically need replacement first.