The LX4FJ340 is a replacement contactor coil in the TeSys F range, built for 340 V DC control circuits. It's the drop-in magnet coil for TeSys F contactors that use the LX4FJ frame — if your panel has an F-line contactor with a burned or open coil, this is the factory service part. Opening time runs 45 to 60 ms, closing 50 to 60 ms, which is standard for a DC-operated contactor of this frame size. The coil draws 1000 W inrush and settles to 6 W holding, so the control transformer or DC supply needs to handle that inrush peak without dropping out the rest of the circuit.
Control circuit and voltage limits
Rated control voltage is 340 V DC, with an operational range of 0.85 to 1.1 Uc at 131 °F (55 °C). Drop-out happens between 0.2 and 0.35 Uc. This coil has no built-in suppressor module. If your application drives inductive loads near sensitive electronics, you'll want an external flyback diode or RC snubber across the coil terminals. The holding resistance is 33750 Ohm at 68 °F (20 °C), so the steady-state current is about 10 mA — easy on the control transformer once it's picked up.
What to watch when ordering
Ambient temperature range for operation is 23 to 131 °F (-5 to 55 °C). If your panel runs hotter — say near a furnace or in a sun-baked enclosure — you'll need to check the thermal derating for the contactor assembly, not just the coil.