VLT PowerCards

Danfoss VLT PowerCards are the internal power-section boards inside VLT frequency converters and are treated as critical components in the drive's protection and fault supervision. Each card incorporates a switch-mode power supply that generates the converter's internal control voltages. Which supply rails are monitored depends on the active source, either a 24 V backup input or the main AC line. The PowerCards are also integrated with thermal management and gate-drive communications, carrying heat-sink and IGBT temperature signals and the links to the gate-drive circuitry used for diagnostics. In higher-power frames or multi-module systems, faults related to a PowerCard can be tagged by module position, allowing the controller to pinpoint which power section raised the alarm. Proper selection and installation of associated scaling and interconnection hardware are mandatory; if these elements are missing, mismatched, or incorrectly fitted, the drive will issue a power-section configuration fault.