The LX1FF140 is a replacement coil for the TeSys F contactor range, wound for 140 V AC 50 Hz control circuits. It's the part you swap when the original coil opens or shorts — not a whole contactor, just the electromagnetic driver that pulls the main poles in. Rated for 550 VA inrush and 45 VA hold-in at 50 Hz, cos φ 0.3. That inrush figure governs the control transformer sizing — a 100 VA transformer won't cut it if you're energizing this coil through a long cable run.
Drop-out voltage is 0.35 to 0.55 Uc (49 to 77 V AC), operational range is 0.85 to 1.1 Uc (119 to 154 V AC) at 55 °C. If your control voltage sags below 119 V under load, the coil may chatter or drop out — common in mills with long 120 V control runs and undersized transformers. Closing time is 23 to 35 ms, opening 5 to 15 ms. That's fast enough for standard motor starting but not for high-speed synchronous transfer switching — the opening delay matters if you're sequencing contactors in a reversing starter. Heat dissipation runs 12 to 16 W at 50 Hz. In a densely packed panel, that's non-trivial — adjacent PLC or relay modules may see a 5 to 10 °C temperature rise if the coil is continuously energized. Leave a slot gap or use a lower-hold coil if the panel runs hot. That's about 40 operations per minute — fine for a conveyor jog sequence, but not for a high-speed pick-and-place application where you'd want a DC-operated or electronic coil.
The coil has no built-in suppressor module — you'll need to add a varistor or RC snubber across the coil terminals if the control circuit drives solid-state outputs or a PLC. Without suppression, the inductive kick from the 1.39 H closed-circuit inductance can weld relay contacts or damage triac outputs.