Drives (VFDs)
Danfoss VLT HVAC Drive FC 102 fault codes
What all 73 Danfoss VLT HVAC Drive FC 102 fault codes mean, in plain words, with a risk grade for each. These come from the manufacturer's own manual. The fix for each one is in WERCS Diagnose.
Get the fixes · plans from $49/moUpdated November 4, 2026
| Code | What it means | Risk |
|---|---|---|
| 1 | 10 Volts low The drive control card voltage is below ten volts, causing the motor to stop running. | GREEN |
| 2 | Live zero error An analog input signal is below half of its programmed minimum, causing the drive to fault. | YELLOW |
| 4 | Mains phase loss The drive has a missing supply phase or high voltage imbalance, causing the motor to stop. | YELLOW |
| 5 | DC link voltage high The drive intermediate circuit voltage exceeds the high warning limit, but the unit remains active. | GREEN |
| 6 | DC link voltage low The drive intermediate circuit voltage is below the low warning limit, but the unit remains active. | GREEN |
| 7 | DC overvoltage The drive intermediate circuit voltage exceeds the maximum limit, causing the unit to trip and stop. | YELLOW |
| 8 | DC undervoltage The drive voltage dropped below the undervoltage limit without a backup supply, causing the unit to trip. | YELLOW |
| 9 | Inverter overload The drive is about to cut out due to an overload, which will stop the fan motor. | YELLOW |
| 10 | Motor overload temperature The drive will fault because the motor has become too hot from running with an overload for an extended period. | YELLOW |
| 11 | Motor thermistor over-temp The drive issues a warning or alarm indicating that the motor thermistor is disconnected or too hot. | YELLOW |
| 12 | Torque limit The drive warns that the motor torque has exceeded the programmed limit for either motor or generator mode. | YELLOW |
| 13 | Overcurrent The drive trips and issues an alarm because the peak current limit has been exceeded for more than one and a half seconds. | YELLOW |
| 14 | Ground fault The drive detects current leaking to ground in the motor or the motor cable and will stop operating. | RED |
| 15 | Hardware mismatch A fitted option is incompatible with the current control board, preventing that specific option from operating. | YELLOW |
| 16 | Short-circuit The drive will stop because it has detected a short circuit in the motor or the motor wiring. | RED |
| 17 | Control word timeout There is no communication to the adjustable frequency drive, which stops the drive from operating. | YELLOW |
| 18 | Start failed The drive fails to start because the motor speed could not reach the required minimum RPM within the allowed time. | YELLOW |
| 23 | Internal fan fault A protective warning indicates that the internal fan is either not running or not mounted properly. | GREEN |
| 24 | External fan fault A protective warning indicates that the external fan is either not running or not mounted properly. | GREEN |
| 25 | Brake resistor short-circuit The brake function is disabled and a warning appears because a short circuit has occurred in the brake resistor. | GREEN |
| 26 | Brake resistor power limit The drive issues a warning or trips because the dissipated braking energy has exceeded the safe power limit of the brake resistor. | YELLOW |
| 27 | Brake chopper fault The brake function is disabled and a warning is issued because a short circuit occurred in the brake transistor. | YELLOW |
| 28 | Brake check failed The braking system will not function because the brake resistor is either disconnected or completely broken. | YELLOW |
| 29 | Heatsink temp The drive heatsink has exceeded its maximum temperature and will remain locked out until it cools down sufficiently. | YELLOW |
| 30 | Motor phase U missing The drive will not run the motor because the U phase connection between the drive and the motor is missing. | YELLOW |
| 31 | Motor phase V missing The drive will not run the motor because the V phase connection between the drive and the motor is missing. | YELLOW |
| 32 | Motor phase W missing The drive will not run the motor because the W phase connection between the drive and the motor is missing. | YELLOW |
| 33 | Inrush fault The drive faults and stops operating because too many power-ups have occurred within a very short time period. | YELLOW |
| 34 | Fieldbus communication fault The drive loses network control because the serial communication bus on the option card is not working. | YELLOW |
| 36 | Mains failure The drive issues an alarm and stops because the main supply voltage to the unit has been lost. | YELLOW |
| 38 | Internal fault The drive stops operating and displays a specific code number indicating that an internal hardware or software fault has occurred. | YELLOW |
| 39 | Heatsink sensor The drive will fault because it is receiving no feedback signal from the heatsink temperature sensor on the power card. | YELLOW |
| 40 | Overload of digital output terminal 27 The drive faults because the load connected to digital output terminal 27 is overloaded or short-circuited. | GREEN |
| 41 | Overload of digital output terminal 29 The drive faults because the load connected to digital output terminal 29 is overloaded or short-circuited. | GREEN |
| 42 | Overload of digital output on X30/6 or overload of digital output on X30/7 The drive faults because the load connected to digital output X30/6 or X30/7 is overloaded or short-circuited. | GREEN |
| 45 | Ground fault 2 The drive stops operating because it has detected a secondary ground fault in the system. | RED |
| 46 | Power card supply The drive will not operate because the electrical supply on the power card is out of the acceptable range. | YELLOW |
| 47 | 24 V supply low The drive issues an alarm because the 24-volt DC supply on the control card has dropped below 18 volts. | GREEN |
| 48 | 1.8 V supply low The drive will fault because the internal 1.8-volt DC supply on the control card is outside of allowable limits. | GREEN |
| 49 | Speed limit The drive issues a warning because the motor speed has fallen outside the programmed low or high speed limits. | GREEN |
| 50 | AMA calibration failed The drive cannot operate because the automatic motor adaptation calibration process has failed. | YELLOW |
| 51 | AMA check Unom and Inom The automatic motor adaptation fails because the programmed settings for motor voltage, current, and power are incorrect. | YELLOW |
| 52 | AMA low Inom The automatic motor adaptation fails because the detected motor current is too low for the process to continue. | YELLOW |
| 53 | AMA motor too big The automatic motor adaptation process cannot run because the connected motor is too large for the drive. | YELLOW |
| 54 | AMA motor too small The automatic motor adaptation process cannot run because the connected motor is too small for the drive. | YELLOW |
| 55 | AMA parameter out of range The automatic motor adaptation cannot run because the programmed motor parameter values are outside the acceptable range. | YELLOW |
| 56 | AMA interrupted by user The automatic motor adaptation process has stopped because it was manually interrupted by a user. | YELLOW |
| 57 | AMA internal fault An internal fault occurred during the automatic motor adaptation, which stops the drive from running. | YELLOW |
| 58 | AMA Internal fault The automatic motor adaptation process has failed completely due to a severe internal drive fault. | YELLOW |
| 59 | Current limit The drive issues a warning or stops because the motor current has exceeded the programmed current limit. | GREEN |
| 60 | External interlock The drive trips and stops the motor because an external interlock signal indicates a fault condition outside the drive. | GREEN |
| 62 | Output frequency at maximum limit The drive issues a warning because the output frequency has reached its programmed maximum limit. | GREEN |
| 65 | Control card overtemperature The drive shuts down because the control card has reached its maximum cut-out temperature of 176 degrees Fahrenheit. | YELLOW |
| 66 | Heatsink temperature low The drive will not operate because the heatsink temperature sensor indicates the unit is too cold. | GREEN |
| 67 | Option module configuration has changed One or more options were added or removed since the last power down, which prevents the drive from starting. | YELLOW |
| 68 | Safe Stop activated The drive stops the motor immediately because the safe torque off function has been activated. | RED |
| 69 | Power card temperature The drive stops operating because the temperature sensor on the power card is reading either too hot or too cold. | YELLOW |
| 70 | Illegal FC configuration The control card and power card are incompatible, which prevents the drive from operating entirely. | YELLOW |
| 80 | Drive initialized to default value The drive has wiped its custom programming and returned all parameter settings to their factory defaults. | YELLOW |
| 92 | No-Flow The drive issues a warning or stops because it has detected a no-flow condition in the system. | YELLOW |
| 93 | Dry pump The drive detects a high-speed no-flow condition, which indicates the pump is running dry and may stop. | YELLOW |
| 94 | End of curve The drive warns of a possible system leak because the feedback remains lower than the required setpoint. | YELLOW |
| 95 | Broken belt The drive stops the motor because the torque has dropped below the no-load level, indicating a broken belt. | YELLOW |
| 96 | Start delayed The drive delays starting the motor to protect the equipment from short-cycling damage. | YELLOW |
| 97 | Stop delayed The drive delays stopping the motor to protect the equipment from short-cycling damage. | GREEN |
| 98 | Clock fault The drive issues a warning because the internal clock is not set or has completely failed. | GREEN |
| 200 | Fire mode The drive issues a warning to indicate that it is currently operating in emergency fire mode. | RED |
| 201 | Fire Mode was Active The drive indicates that it had previously entered emergency fire mode during a past event. | RED |
| 202 | Fire mode limits exceeded The drive warns that it has ignored critical alarm conditions to keep running while in fire mode. | RED |
| 203 | Missing motor The drive detects an underload condition in a multi-motor setup, which indicates a motor is missing or disconnected. | GREEN |
| 204 | Locked rotor The drive detects an overload condition in a multi-motor setup, which indicates a motor has a locked rotor. | GREEN |
| 250 | New spare part A component in the adjustable frequency drive was replaced, which prevents the drive from running until configured. | GREEN |
| 251 | New type code The power card or other components were swapped out and the type code changed, causing the drive to stop. | GREEN |
Every code comes from the manufacturer's own manual. Subscribers see which manual and page.