Drives (VFDs)
Siemens SINAMICS V20 VFD fault codes
What all 54 Siemens SINAMICS V20 VFD 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 |
|---|---|---|
| F1 | Overcurrent The drive has detected an overcurrent condition, which causes the equipment to stop running immediately. | RED |
| F2 | Overvoltage The drive has detected an overvoltage condition, which forces the booth equipment to shut down. | YELLOW |
| F3 | Undervoltage The drive has detected an undervoltage condition, causing the booth equipment to stop operating. | YELLOW |
| F4 | Converter overtemperature The converter has reached an overtemperature condition, which causes the drive to stop the booth equipment. | YELLOW |
| F5 | Converter I2t The converter has exceeded its thermal current limit, causing the drive to stop the equipment. | YELLOW |
| F6 | Chip temperature rise exceeds critical levels The internal chip temperature rise has exceeded critical levels, which forces the drive to stop the booth. | YELLOW |
| F11 | Motor overtemperature The motor has reached an overtemperature condition, causing the drive to shut down the booth equipment. | YELLOW |
| F12 | Converter temperature signal lost The converter heat sink temperature sensor has a broken wire, which causes the drive to stop the equipment. | YELLOW |
| F20 | DC ripple too high The calculated direct current ripple level has exceeded the safe threshold, causing the drive to stop the booth. | RED |
| F23 | Output current ripple too high The calculated output ripple level has exceeded the safe threshold, which forces the drive to stop the equipment. | RED |
| F35 | Maximum number of auto restart attempts exceeded The auto restart attempts exceeded the maximum allowed value, which causes the drive to fault and stop trying to start. | YELLOW |
| F41 | Motor data identification failure The motor data identification process has failed, which prevents the drive from starting the booth equipment. | YELLOW |
| F51 | Parameter EEPROM fault A read or write failure occurred while accessing the memory, which prevents the drive from operating the booth. | YELLOW |
| F52 | Converter software fault A read failure for converter information or invalid data has occurred, causing the drive to stop the equipment. | YELLOW |
| F60 | Asic timeout An internal communications failure has occurred, which forces the drive to shut down the booth equipment. | YELLOW |
| F61 | SD card parameter cloning failed The parameter cloning process has failed, which prevents the drive from starting the booth equipment. | YELLOW |
| F62 | Parameter cloning contents invalid The cloning file exists but contains invalid data, which prevents the drive from operating the booth. | YELLOW |
| F63 | Parameter cloning contents incompatible The cloning file exists but is the wrong converter type, preventing the drive from loading the parameters. | YELLOW |
| F64 | Converter attempted to do an automatic clone during startup The required clone file is missing from the correct directory, which prevents the drive from starting the equipment. | YELLOW |
| F70 | I/O Extension Module communication fault Communication is no longer established with the extension module, causing the drive to stop the booth equipment. | YELLOW |
| F71 | USS setpoint fault (on RS232) The drive is receiving no setpoint values during the telegram off time, which causes the equipment to stop. | YELLOW |
| F72 | USS/MODBUS setpoint fault (on RS485) The drive is missing setpoint values from the communication network, causing the booth equipment to shut down. | YELLOW |
| F80 | Signal lost on analog input The signal has been lost on the analog input, which forces the drive to stop the booth equipment. | YELLOW |
| F85 | External fault An external fault has been triggered via the command input, causing the drive to stop the equipment. | YELLOW |
| A501 | Current limit The drive has reached its current limit, which triggers a warning but allows the booth equipment to keep running. | GREEN |
| A502 | Overvoltage limit The overvoltage limit has been reached during ramp down, which triggers a warning without stopping the booth equipment. | GREEN |
| A503 | Undervoltage limit The drive has reached its undervoltage limit, which generates a warning while the booth equipment continues to operate. | GREEN |
| A504 | Converter overtemperature The converter temperature warning level is exceeded, which reduces the output frequency while the booth equipment continues running. | GREEN |
| A505 | Converter I2t The converter thermal warning level has been exceeded, which reduces the current while the booth equipment keeps running. | GREEN |
| A506 | IGBT junction temperature rise warning The temperature difference between the heat sink and transistor exceeds warning limits, which alerts the operator without stopping the booth. | GREEN |
| A507 | Converter temperature signal lost The converter heat sink temperature signal has been lost, which triggers a warning but allows the equipment to run. | GREEN |
| A511 | Motor overtemperature I2t The motor is overloaded due to high load cycles or steps, which stops the drive to prevent damage. | GREEN |
| A523 | Output current ripple too high The calculated output ripple level has exceeded the safe threshold, which triggers a warning without stopping the booth equipment. | RED |
| A535 | Braking resistor overload The braking energy is too large for the resistor, which generates a warning while the booth equipment keeps running. | GREEN |
| A541 | Motor data identification active The motor data identification process is currently running, which keeps the drive busy before the booth can start. | GREEN |
| A600 | RTOS overrun warning An internal time slice overrun has occurred, which triggers a warning while the drive continues to operate the booth. | GREEN |
| A910 | Vdc_max controller deactivated The maximum voltage controller has deactivated due to high supply voltage, which triggers a warning without stopping the booth. | GREEN |
| A911 | Vdc_max controller active The maximum voltage controller is actively keeping the direct current link voltage below the specified limit while the booth runs. | GREEN |
| A912 | Vdc_min controller active The minimum voltage controller has activated because the direct current link voltage fell below the specified limit during operation. | GREEN |
| A921 | Analog output parameters not set properly The analog output parameters are set to identical values, which produces illogical results and triggers a warning on the drive. | GREEN |
| A922 | No load applied to converter There is no load applied to the converter, which causes some functions to operate differently while the booth runs. | GREEN |
| A923 | Both JOG left and JOG right are requested Both left and right jog commands have been requested simultaneously, which freezes the output frequency at its current value. | GREEN |
| A930 | Cavitation protection warn Conditions exist for possible pump cavitation damage, which triggers a warning while the booth equipment continues to operate. | GREEN |
| A936 | PID autotuning active The proportional integral derivative autotuning process is currently running, which keeps the drive busy before normal booth operation begins. | GREEN |
| A952 | Load monitoring warning The motor load conditions indicate a potential belt failure or mechanical fault, which triggers a warning without stopping the booth. | GREEN |
| F100 | Watchdog reset A software error has occurred within the drive, which forces the booth equipment to shut down immediately. | YELLOW |
| F101 | Stack overflow A software error or processor failure has occurred, causing the drive to stop operating the booth equipment. | YELLOW |
| F200 | Script error The internal converter program script has stopped running due to errors, which causes the drive to shut down. | YELLOW |
| F221 | PID feedback below minimum value The proportional integral derivative feedback has fallen below the minimum value, causing the drive to stop the equipment. | YELLOW |
| F222 | PID feedback above maximum value The proportional integral derivative feedback has exceeded the maximum value, which forces the drive to stop the booth. | YELLOW |
| F350 | Configuration vector for the converter failed The hardware does not match the programmed configuration vector, which causes the drive to trip and stop the booth. | YELLOW |
| F395 | Acceptance test/confirmation pending An acceptance test is pending after a startup clone or memory read error, which prevents the drive from starting. | YELLOW |
| F410 | Cavitation protection failure Conditions exist for potential pump cavitation damage due to insufficient fluid flow, causing the drive to stop the equipment. | YELLOW |
| F452 | Load monitoring trip The motor load conditions indicate a belt failure or mechanical fault, which forces the drive to stop the booth. | YELLOW |
Every code comes from the manufacturer's own manual. Subscribers see which manual and page.