What this braking unit does
The VFDB4045 is a DC-bus braking unit for VFD applications, sized for a 45 kW motor load. It connects across the 400—800 VDC bus of a compatible drive and dumps regenerative energy into an external resistor bank. The IP50 wall-mount enclosure keeps dust out but isn't rated for washdown — mount it inside the panel or in a clean electrical room.
The 400—800 VDC input range covers common 400 V and 480 V class drives with a DC bus that typically sits around 560–680 VDC under load. The 45 kW motor capacity is the maximum induction motor size this unit can decelerate — oversizing the braking unit relative to the drive is fine, but undersizing it for the motor will trip the overvoltage fault on decel. Minimum equivalent resistor of 13.6 Ω per unit sets the floor on the external resistor value; going lower risks overcurrent on the braking transistor.