Danfoss VLT Brake Resistors are external braking components designed for use with multiple VLT frequency converter families, including FC 51, FC 102, FC 202, FC 300/301/302, FC 360, FCD 302, and VLT 2800 drives.
Their function is to absorb regenerative energy from the drive DC link during deceleration so the converter can brake more effectively without reaching DC-link overvoltage trip conditions. The series is organized for horizontal-load and vertical-load applications and includes aluminium-housed flat-pack resistors, aluminium-housed compact resistors, and steel-grid resistors, each with different pulse-load capability and enclosure options. Installation requirements include natural-convection cooling with defined mounting clearances and orientation rules, EMC-conscious cable routing, and shielded brake-cable connection practices for the resistor-to-drive wiring. The series also incorporates overtemperature protection via a built-in temperature switch on the resistor assembly, and proper selection is based on application braking profile factors such as resistor value, peak braking power, average braking power, duty cycle, and inertia.
