24VNA6 / 25VNA4 seriesCarrier 84 fault code (24VNA6 / 25VNA4)

VFD Heat Sink Overtemp Shutdown

1. Code 84-11 VFD Overtemp Limiting / Code 84-58 VFD Overtemp Lockout

   The VFD has internal temperature sensors to monitor critical power components and take action if operating temperatures cross thresholds that may shorten the VFDs operating life. If the heat sink temperature sensor fails, it will no longer be capable of preventing critical power components from operation above the safe reliable temperature threshold. If this fault is active, the VFD will shut down compressor but continue to operate fan to draw air across heat sink. Once heat sink temperature is acceptable, system will restart but reduce demand by 25% for each occurrence of 84-11. Once speed can no longer be reduced further, code 84-58 will be set and system locked out for 2 hours. Each hour of operation without additional code 84-11 will allow increased demand of 25%. The most likely cause is restricted airflow over heat sink. Inspect and clear heatsink of anything that may inhibit airflow or contact with air. A less likely possibility is inadequate contact of power components with heat sink, not allowing intended heat transfer between components and heat sink. If clearing heatsink of blockage does not eliminate codes, replace VFD.

   24VNA6-25VNA4-1SM, p. 22