The LX0FJ057 is a replacement contactor coil from the Schneider Electric TeSys F range, designed for DC low-consumption control circuits at 127 V DC nominal. It handles the latching and unlatching cycle for the contactor armature: unlatching takes 50...100 ms, latching takes 40...75 ms. That timing window matters when you're coordinating with downstream logic or safety interlocks — the coil needs to see the full voltage pulse for at least that long to pull in or drop out reliably.
On a 127 V DC nominal coil, that means it holds in from about 108 V DC to 140 V DC. If your DC bus sags below 108 V during a brownout or heavy motor start, the contactor drops out — plan your control transformer tap or DC supply headroom accordingly. Maximum operating rate is 120 cycles per hour at 104 °F (40 °C). That's one cycle every 30 seconds. If your application cycles faster — say a rapid-reversing conveyor or a jogging station — this coil will overheat. You'd need a higher-duty variant or a derating curve from the TeSys F documentation. Mechanical durability is rated at 1 million cycles. That's the mechanical life of the coil itself, not the contactor's electrical life under load. For a coil that cycles once per minute, that's about 2 years of continuous 24/7 operation before the armature guide or plunger wears out. Plan spares accordingly. Coil resistance at 68 °F (20 °C) is 31.86 ohms in the latching state and 221.2 ohms in the unlatching state. The resistance jump tells you the coil has a holding-economy design — it draws higher inrush to pull in, then drops to a lower holding current. Use that latching resistance to calculate the peak current draw for your DC supply sizing.
This coil mounts into a TeSys F contactor frame. The LX0FJ short name identifies it as a DC low-consumption coil variant for the F-frame. When swapping an old coil, match the full order code — LX0FJ057 — not just the voltage class, because the low-consumption electronics differ from the standard DC coil. The operating time and resistance values above are specific to this variant.
No need to hunt surplus or second-source — the official channel carries it. The category code US1CP1018401 is the internal Schneider classification; it doesn't change the fit, but it's useful for cross-referencing in their catalog system if you're ordering through a distributor portal.