The LTi SO84.325 is an ultra-high-power three-phase servo drive in the BG7 housing, delivering 325A continuous and 552A peak current. Designed for the most demanding industrial applications, it requires liquid cooling and external precharging.
Rated current: 325 A (400V, 2 kHz), peak: 552 A (0-5 Hz)
Mains: 3 x 230V to 480V AC ±10%
Switching frequencies: 2 kHz, 4 kHz
BG7 dimensions: 380 x 952 x 286.5 mm, weight 100 kg
External mains choke mandatory
External precharging circuit required
Rated current: 325 A (400V, 2 kHz), 300 A (480V)
Peak current: 552 A (0-5 Hz)
Connected load: 225 kVA
Power loss at IN: 4800 W (2 kHz, liquid-cooled)
DC link capacitance: 5400 μF
Brake chopper threshold: 820 V DC
Minimum external braking resistor: 2.5 Ω
Continuous braking power (external): 269 kW
Peak braking power: 269 kW
Optional internal braking resistor: not specified for SO84.325 in manual
Nominal coolant flow: 11 l/min (max 13 l/min)
Coolant pressure: 1 bar nominal / 2 bar max
Coolant temperature: 5°C to 40°C
Shutdown at 65°C heat sink
Control supply: 24 V DC ±10% (4A start, 2A continuous)
Precharge circuit: external contactors K1 (mains), K2 (precharge), K3 (relay)
Recommended mains fuse: 315 A (gG)
Digital I/O: 6 inputs, 3 outputs, relay
Analog inputs: 2 differential (±10V)
Resolver and high-resolution encoder
USB, Ethernet, MMC, option slots

The BG7 requires a robust mounting structure. Connect liquid cooling with 3/8 inch female threads. The external precharging circuit must be wired as shown in the manual: S1 (mains on) closes K2 first to precharge via X45, then K3 closes K1, and K2 opens. Use ring terminal ends for power connections (M10 for DC link, M12 for motor). The external mains choke (uk=2%) and external mains filter (optional) are required.
Commission with DriveManager 5. Apply 24V control supply (X44). The precharge sequence must complete within a few seconds. Enable STO inputs (ISDSH and ENPO) to activate power stage. Parameter sets can be stored to MMC card. The drive supports fieldbus options and iPlc.
The brake chopper can handle 269 kW continuous with external 2.5 Ω resistor. Ensure proper thermal management of the braking resistor. Wire the resistor’s thermal switch to a digital input for protection.
Suitable for servo motors up to 160 kW (400V). Typical applications include large forging presses, heavy-duty extruders, mining conveyors, and large wind turbine generators.
Complies with EN 61800-5-1, EN 61800-3, LVD, EMC. UL approval for BG7 planned.
The LTi SO84.325 provides extreme power for the most demanding single-axis servo systems.



