What the 400 A AC-1 rating means for fit
The LC1F3304FE7 is a 4-pole contactor from the TeSys F range, rated 400 A in AC-1 utilisation category at ≤440 VAC. AC-1 covers resistive loads — heaters, ovens, lighting banks — where the current stays sinusoidal and inrush is minimal. That 400 A figure is the thermal current (Ith) the main poles carry continuously; for motor duty (AC-3) you would derate substantially, but this part is specced for resistive switching. The 115 VAC 40-400 Hz coil draws 650 VA inrush, dropping to 10 VA hold-in, with a dropout band of 0.35 to 0.55 Uc — useful to know if your control transformer is marginal on sag.
Standards, approvals, and electrical backbone
The contactor is designed and certified to IEC 60947-4-1 and EN 60947-4-1 (the contactor and starter standard), plus IEC/EN 60947-1 and JIS C8201-4-1. Rated insulation voltage (Ui) is 1000 V per IEC 60947-4-1, with an impulse withstand voltage (Uimp) of 8 kV — overvoltage category III, meaning it is built for fixed-installation distribution panels. The rated breaking capacity is 2640 A per the same standard, which governs its ability to clear fault currents without welding the main poles. The front face carries IP20 protection with shrouds fitted, per IEC 60529 and VDE 0106.
Mounting and integration
Mounting is plate-based — no DIN-rail clip on this frame size. The power circuit accepts lugs or busbars: one 240 mm² cable per pole via ring terminals, or two busbars with a 30 x 5 mm cross-section. Control wiring uses screw-clamp terminals accepting 1 to 4 mm² flexible or solid. Tightening torque is 35 N.m on the power side and 1.2 N.m on the control circuit. Dimensions are 261 mm wide, 206 mm high, 219 mm deep — factor that into your panel layout and gland-plate planning, especially if retrofitting into an existing enclosure.
Environmental and durability profile
Mechanical durability is rated at 10 million cycles. Maximum operating rate is 2400 cycles per hour at 55 °C. Ambient operating temperature range is -5 to 55 °C; storage range is -60 to 80 °C. The unit is TH-treated for tropical environments (protective treatment against humidity and corrosion). Operating altitude is 3000 m without derating. Heat dissipation is 8 W total, with 44 W per pole in AC-1 duty — thermal management matters in a dense panel.
Coordination and protection
For short-circuit coordination, the associated fuse ratings are 400 A aM (motor-protection) or 500 A gG (general-purpose) at ≤440 V. The average impedance per pole is 0.28 mOhm at 400 A, 50 Hz — a low figure that minimises voltage drop and heat in the power path. Closing time is 40 to 65 ms; opening time is 100 to 170 ms. These are relevant for selectivity studies and for sequencing with upstream breakers or downstream overload relays.