Thermal protection / cooling

Danfoss VLT Cooling and Heatsink Temperature Path

Routes alarm 29 through cooling fans, heatsink contamination, airflow, cabinet ventilation, ambient temperature, load current and temperature feedback.

Functional path

Cabinet airflow

Drive fan

Heatsink

Temperature sensor

Load current

Thermal trip logic

Diagnostic signals and checkpoints

Alarm 29 timingFan operationDust/filter conditionAmbient temperatureLoad current

Technician notes

Cold-start and hot-load alarm 29 cases have different first boundaries.
Thermal protection should not be bypassed to keep production running.