Siemens SINAMICS V20 Drive Fault Codes List (2026) – Access the complete 2026 reference guide for Siemens SINAMICS V20 fault codes. Learn to diagnose Fxxxxx faults via the Basic Operator Panel (BOP) and the V20 Smart Access Module.
The Siemens SINAMICS V20 is the “Basic Performance” drive of choice for pumps, fans, and compressors. Designed for cost-efficiency, it features a built-in Basic Operator Panel (BOP). However, when a trip occurs, the display shows a 5-digit code (e.g., F30001, A0501) that requires specific knowledge to interpret.
This guide provides the most updated reference for 2026 to help you decipher these codes and utilize the optional wireless tools for faster maintenance.
Siemens V20 Fault Codes Reference Table
Use the search bar below or browse the table to identify your specific error code.
| Fault Codes | Cause & Solution |
|---|---|
| F1 Overcurrent | Cause: • Motor power (P0307) does not correspond to the inverter power (r0206). • Motor lead short circuit • Earth faults – r0949 = 0: Hardware reported – r0949 = 1: Software reported – r0949 = 22: Hardware reported Soultion: Check the following: • Motor power (P0307) must correspond to in-verter power (r0206). • Cable length limits must not be exceeded. • Motor cable and motor must have no short- circuits or earth faults. • Motor parameters must match the motor in use. • Value of stator resistance (P0350) must be correct. • Motor must not be obstructed or overloaded. • Increase ramp-up time (P1120) • Reduce starting boost level (P1312) |
| F2 Overvoltage | Cause: • Main supply voltage too high • Motor is in regenerative mode – r0949 = 0: Hardware reported – r0949 = 1 or 2: Software reported Soultion: Check the following: • Supply voltage (P0210) must lie within limits indicated on rating plate. • Ramp-down time (P1121) must match inertia of load. • Required braking power must lie within specified limits. • Vdc controller must be enabled (P1240) and parameterized properly. Note: Regenerative mode can be caused by fast ramp downs or if the motor is driven by an active load. Higher inertia requires longer ramp times; other- wise, apply braking resistor. |
| F3 Undervoltage | Cause: • Main supply failed. • Shock load outside specified limits. – r0949 = 0: Hardware reported – r0949 = 1 or 2: Software reported Soultion: 1. Check supply voltage. 2. Check drive rectifier section using multimeter. |
| F4 Inverter overtemperature | Cause: • Inverter overloaded • Ventilation inadequate • Pulse frequency too high • Surrounding temperature too high • Fan inoperative Soultion: Check the following: • Load or load cycle too high? • Motor power (P0307) must match inverter power (r0206) • Pulse frequency must be set to default value • Surrounding temperature too high? • Fan must turn when inverter is running |
| F5 Inverter I2t | Cause: • Inverter overloaded. • Load cycle too demanding. • Motor power (P0307) exceeds in- verter power capability (r0206). Soultion: Check the following: • Load cycle must lie within specified limits. • Motor power (P0307) must match inverter power (r0206) Note: F5 cannot be cleared until the inverter over- load utilization (r0036) is lower than the inverter I2 t warning (P0294). |
| F6 Chip temperature rise exceeds critical levels | Cause: • Load at start-up is too high • Load step is too high • Ramp-up rate is too fast Soultion: Check the following: • Load or load step too high? • Increase ramp-up time (P1120). • Motor power (P0307) must match inverter power (r0206). • Use setting P0290 = 0 or 2 for preventing F6. |
| F11 Motor overtemperature | Cause 1: Motor overloaded Soultion: Check the following: • Load or load step too high? • Motor nominal overtemperatures (P0626 – P0628) must be correct • Motor temperature warning level (P0604) must match Cause 2: This fault may occur if small motors (≤ 250 W, 4- or 2-pole) are used and run at a frequency below 15 Hz, even though the motor temperature is within limits. Soultion: Check the following: • Motor current is not in excess of the motor nominal current as indicated by the motor rating plate • Physical temperature of the motor lies within limits If these two conditions are satisfied, then set pa- rameter P0335 = 1. |
| F12 Inverter temperature signal lost | Cause: Wire breakage of inverter temperature (heat sink) sensor. Soultion: There is an hardware or software issue in drive. Need to repair or replace drive. |
| F20 DC ripple too high | Cause: The calculated DC ripple level has exceeded the safe threshold. This is commonly caused by loss of one of the mains input phases. Soultion: 1. Check the mains supply wiring. 2. There is an hardware or software issue in drive. Need to repair or replace drive. |
| F35 Maximum number of auto restart attempts exceeded | Cause: Auto restart attempts exceed value of P1211. |
| F41 Motor data identification failure | Cause: Motor data identification failed. • r0949 = 0: No load applied • r0949 = 1: Current limit level reached during identification. • r0949 = 2: Identified stator resistance less than 0.1% or greater than 100%. • r0949 = 30: Current controller at voltage limit • r0949 = 40: Inconsistency of identi- fied dataset, at least one identifica- tion failed Percentage values based on the im- pedance Zb = Vmot,nom / sqrt(3) / Imot,nom Soultion: Check the following: • r0949 = 0: is the motor connected to the inverter? • r0949 = 1 – 49: are the motor data in P0304 – P0311 correct? • Check what type of motor wiring is required (star, delta). |
| F51 Parameter EEPROM fault | Cause: Read or write failure while access to EEPROM. This can also be caused by the EEPROM being full, too many parameters have been changed. Soultion: • Must be power-cycled to cancel this bug as some parameters may not be read correct. • Factory reset and new parameterization, if power-cycle does not remove fault. • Change some parameters back to default val- ues if the EEPROM is full, then power-cycle. • Change inverter. Note: • r0949 = 1: EEPROM full • r0949 = 1000 + block No: reading data block failed • r0949 = 2000 + block No: reading data block timeout • r0949 = 3000 + block No: reading data block CRC failed • r0949 = 4000 + block No: writing data block failed • r0949 = 5000 + block No: writing data block timeout • r0949 = 6000 + block No: writing data block verify failed • r0949 = 7000 + block No: reading data block at wrong time • r0949 = 8000 + block No: writing data block at wrong time • r0949 = 9000 + block No: factory reset did not work because restart or power failure |
| F52 Inverter software fault | Cause: Read failure for inverter information or invalid data. Soultion: 1. Power-cycle inverter. 2. After power recycle same fault comes then there is an hardware or software issue in drive. Need to repair or replace drive. Note: • r0949 = 1: Failed reading inverter identity • r0949 = 2: Inverter identity wrong • r0949 = 3: Failed reading inverter version • r0949 = 4: Inverter version wrong • r0949 = 5: Start of Part 1 inverter data wrong • r0949 = 6: Inverter number of temperature sensor wrong • r0949 = 7: Inverter number of application wrong • r0949 = 8: Start of Part 3 inverter data wrong • r0949 = 9: Reading inverter data string wrong • r0949 = 10: Inverter CRC failed • r0949 = 11: Inverter is blank • r0949 = 15: Failed CRC of inverter block 0 • r0949 = 16: Failed CRC of inverter block 1 • r0949 = 17: Failed CRC of inverter block 2 • r0949 = 20: Inverter invalid • r0949 = 30: Directory size wrong • r0949 = 31: Directory ID wrong • r0949 = 32: Invalid block • r0949 = 33: File size wrong • r0949 = 34: Data section size wrong • r0949 = 35: Block section size wrong • r0949 = 36: RAM size exceeded • r0949 = 37: Parameter size wrong • r0949 = 38: Device header wrong • r0949 = 39: Invalid file pointer • r0949 = 40: Scaling block version wrong • r0949 = 41: Calibration block version wrong • r0949 = 50: Wrong serial number format • r0949 = 51: Wrong serial number format start • r0949 = 52: Wrong serial number format end • r0949 = 53: Wrong serial number format month• r0949 = 54: Wrong serial number format day • r0949 = 1000 + addr: Inverter read data failed • r0949 = 2000 + addr: Inverter write data failed • r0949 = 3000 + addr: Inverter read data wrong time • r0949 = 4000 + addr: Inverter write data wrong time • r0949 = 5000 + addr: Inverter read data invalid • r0949 = 6000 + addr: Inverter write data invalid |
| F60 Asic timeout | Cause: Internal communications failure. Soultion: 1. Check inverter. 2. Fault appears sporadically: Note: • r0949 = 0: Hardware reported link fail • r0949 = 1: Software reported link fail • r0949 = 6: Feedback is not disabled for reading inverter data • r0949 = 7: During inverter download, message didn’t transmit to disable feedback • Communication failure due to EMC problems • Check – and if necessary – improve EMC • Use EMC filter |
| F61 MMC/SD card parameter cloning failed | Cause: Parameter cloning failed. Check Aux. code: • r0949 = 0: MMC/SD card not connected or incorrect card type or the card failed to initialize for automatic cloning • r0949 = 1: Inverter data cannot write to the card. • r0949 = 2: Parameter cloning file not available • r0949 = 3: The MMC/SD card can- not read the file • r0949 = 4: Reading data from the clone file failed (e.g., reading failed, data or checksum wrong) Solution: • r0949 = 0: Use an MMC/SD card with FAT16 or FAT32 format , or fit an MMC/SD card to the inverter. • r0949 = 1: Check the MMC/SD card (e.g., is the card memory full?) – format the card again to FAT16 or FAT32. • r0949 = 2: Put the correct named file in the correct directory /USER/SINAMICS/DATA. • r0949 = 3: Make sure file is accessible – recreate file if possible. • r0949 = 4: File has been changed – recreate file. |
| F62 Parameter cloning contents invalid | Cause: File exists but the contents are not valid control word corruption. Soultion: Recopy and ensure operation completes. |
| F63 Parameter cloning contents incompatible | Cause: File exists but was not the correct inverter type. Soultion: Ensure clone from compatible inverter type. |
| F64 Inverter attempted to do an automatic clone during startup | Cause: No Clone00.bin file in the correct directory /USER/SINAMICS/DATA. Soultion: If an automatic clone is required: • Insert the MMC/SD card with correct file and power-cycle. If no automatic clone is required: • Remove the card if not needed and power- cycle. • Reset P8458 = 0 and power-cycle. Note: Fault can only be cleared by a power-cycle. |
| F71 USS setpoint fault | Cause: No setpoint values from USS during telegram off time Soultion: 1. Check USS master |
| F72 USS/MODBUS setpoint fault | Cause: No setpoint values from USS/MODBUS during telegram off time Soultion: 1. Check USS/MODBUS master. |
| F80 Signal lost on analog input | Cause: • Broken wire • Signal out of limits Solution: 1. Check control wiring. |
| F85 External fault | Cause: External fault triggered via command input via control word 2, bit 13. Soultion: • Check P2106. • Disable control word 2 bit 13 as command source. • Disable terminal input for fault trigger. |
| F100 Watchdog reset | Cause: Software Error. Soultion: There is an hardware or software issue in drive. Need to repair or replace drive. |
| F101 Stack overflow | Cause: Software error or processor failure. Soultion: There is an hardware or software issue in drive. Need to repair or replace drive. |
| F221 PID feedback below minimum value | Cause: PID feedback below minimum value P2268. Soultion: • Change value of P2268. • Adjust feedback gain. |
| F222 PID feedback above maximum value | Cause: PID feedback above maximum value P2267. Soultion: • Change value of P2267. • Adjust feedback gain. |
| F350 Configuration vector for the inverter failed | Cause: During startup the inverter checks if the configuration vector (SZL vector) has been programmed correctly and if hardware matches the programmed vector. If not the inverter will trip. • r0949 = 1: Internal failure – no hardware configuration vector available. • r0949 = 2: Internal failure – no software configuration vector available. • r0949 = 11: Internal failure – inverter code not supported. • r0949 = 12: Internal failure – software vector not possible. Soultion: Internal failures cannot be fixed. – r0949 = 13 – Make sure the right power module is fitted. Note: Fault needs power-cycle to be acknowledged. |
| F395 Acceptance test/confirmation pending | Cause: This fault occurs after a startup clone. It can also be caused by a faulty read from the EEPROM, see F51 for more details. A startup clone could have changed and might not match the application. This parameter set needs to be checked before the inverter can start a motor. • r0949 = 3/4: Inverter data change • r0949 = 5: Startup clone via an MMC/SD card has been performed • r0949 = 10: Previous startup clone was aborted Soultion: – The current parameter set needs to be checked and confirmed by clearing the fault. |
| F410 Cavitation protection failure | Cause: Conditions exist for cavitation damage. Cavitation damage is damage caused to a pump in pumping systems when the fluid is not flowing sufficiently. This can lead to heat build up and subsequent damage to the pump. Soultion: If cavitation is not occurring, reduce the cavitation threshhold P2361, or increase the cavitation protection delay. Ensure sensor feedback is working. |
| F452 Load monitoring trip | Cause: Load conditions on motor indicate belt failure or mechanical fault. • r0949 = 0: trip low torque / speed • r0949 = 1: trip high torque / speed Soultion: 1. Check the following: • No breakage, seizure or obstruction of inverter train. • Apply lubrication if required. 2. If using an external speed sensor, check the following parameters for correct function: – P2192 (delay time for permitted deviation) – P2182 (threshold frequency f1) – P2183 (threshold frequency f2) – P2184 (threshold frequency f3) 3. If using a specific torque / speed range, check parameters: – P2182 (threshold frequency 1) – P2183 (threshold frequency 2) – P2184 (threshold frequency 3) – P2185 (upper torque threshold 1) – P2186 (lower torque threshold 1) – P2187 (upper torque threshold 2) – P2188 (lower torque threshold 2) – P2189 (upper torque threshold 3) – P2190 (lower torque threshold 3) – P2192 (delay time for permitted deviation) |
| A501 Current limit | Cause 1: • Motor power does not correspond to the inverter power • Motor leads are too long • Earth faults Soultion: Check the following: • Motor power (P0307) must correspond to in-verter power (r0206). • Cable length limits must not be exceeded. • Motor cable and motor must have no short- circuits or earth faults. • Motor parameters must match the motor in use. • Value of stator resistance (P0350) must be correct. • Motor must not be obstructed or overloaded. • Increase ramp-up time (P1120) • Reduce starting boost level (P1312) Cause 2: • Small motors (120 W) under FCC and light load may cause a high current Solution: Use V/f operation for very small motors. |
| A502 Overvoltage limit | Cause: Overvoltage limit is reached. This warning can occur during ramp down, if the Vdc controller is disabled (P1240 = 0). Soultion: If this warning is displayed permanently, check inverter input voltage. |
| A503 Undervoltage limit | Cause: • Main supply failed. • Main supply and consequently DC-link voltage (r0026) below specified limit. Soultion: 1. Check main supply voltage. |
| A504 Inverter overtemperature | Cause: Warning level of inverter heat sink temperature, warning level of chip junction temperature, or allowed change in temperature on chip junction is exceeded, resulting in pulse frequency reduction and / or output frequency reduction (depending on parameterization in P0290). Note: r0037[0]: Heat sink temperature r0037[1]: Chip junction temperature (includes heat sink) Soultion: Check the following: • Surrounding temperature must lie within specified limits • Load conditions and load steps must be appro- priate • Fan must turn when inverter is running |
| A505 Inverter I2t | Cause: Warning level exceeded, current will be reduced if parameterized (P0610 = 1). Soultion: 1. Check that load cycle lies within specified limits. |
| A506 IGBT junction temperature rise warning | Cause: Overload warning. Difference between heat sink and IGBT junction temperature ex- ceeds warning limits. Soultion: 1. Check that load steps and shock loads lie within specified limits. |
| A507 Inverter temperature signal lost | Cause: Inverter heat sink temperature signal loss. Possible sensor fallen off. Soultion: There is an hardware or software issue in drive. Need to repair or replace drive. |
| A511 Motor overtemperature I2t | Cause: • Motor overloaded. • Load cycles or load steps too high. Soultion: Independently of the kind of temperature determination check: • P0604 motor temperature warning threshold • P0625 motor surrounding temperature • Check if name plate data is correct. If not, per- form quick commissioning. Accurate equivalent circuit data can be found by performing motor identification (P1900 = 2). • Check if motor weight (P0344) is reasonable. Change if necessary. • With P0626, P0627, and P0628 the standard overtemperature can be changed, If the motor is not a SIEMENS standard motor. |
| A535 Braking resistor overload | Cause: The braking energy is too large. The braking resistor is not suited for the application. Soultion: 1. Reduce the braking energy. 2. Use a braking resistor with a higher rating. |
| A541 Motor data identification active | Cause: Motor data identification (P1900) selected or running. Soultion: This is a informative warning. |
| A600 RTOS overrun warning | Cause: Internal time slice overrun. Soultion: There is an hardware or software issue in drive. Need to repair or replace drive. |
| A910 Vdc_max controller de-activated | Cause: • if main supply voltage (P0210) is permanently too high. • if motor is driven by an active load, causing motor to go into regenerative mode. • at very high load inertias, when ramping down. If warning A910 occurs while the inverter is in standby (output pulses disabled) and an ON command is subsequently given, the Vdc_max controller (A911) will not be activated unless warning A910 is rectified. Soultion: Check the following: • Input voltage must lie within range. • Load must be match. • In certain cases apply braking resistor. |
| A911 Vdc_max controller active | Cause: The Vdc_max controller works to keep the DC-link voltage (r0026) below the level specified in r1242. Soultion: Check the following: • Supply voltage must lie within limits indicated on rating plate. • Ramp-down time (P1121) must match inertia of load. Note: Higher inertia requires longer ramp times; other- wise, apply braking resistor. |
| A912 Vdc_min controller active | Cause: The Vdc_min controller will be activated if the DC-link voltage (r0026) falls below the level specified in r1246. The kinetic energy of the motor is used to buffer the DC-link voltage, thus causing deceleration of the inverter! So short mains failures do not necessarily lead to an un- dervoltage trip. Note: that this warning may also occur on fast ramp-ups. |
| A921 Analog output parameters not set properly | Cause: Analog output parameters (P0777 and P0779) should not be set to identical values, since this would produce illogical results. Soultion: Check the following: • Parameter settings for output identical • Parameter settings for input identical • Parameter settings for output do not correspond to analog output type Set P0777 and P0779 to different values. |
| A922 No load applied to inverter | Cause: No Load is applied to the inverter. As a result, some functions may not work as under normal load conditions. Soultion: 1. Check that motor is connected to inverter. 2. This alarm comes when you run drive without motor or rating of motor is small as compare to drive. |
| A923 Both JOG left and JOG right are requested | Cause: Both JOG right and JOG left (P1055 / P1056) have been requested. This freezes the RFG output frequency at its current value. Soultion: Do not press JOG right and left simultaneously. |
| A930 Cavitation protection warning | Cause: Conditions exist for possible cavitation damage. Soultion: If cavitation is not occurring, reduce the cavitation threshhold P2361, or increase the cavitation protection delay. Ensure sensor feedback is working. |
| A936 PID autotuning active | Cause: PID autotuning (P2350) selected or running Warning disappears when PID autotuning has finished. Soultion: This is a informative warning. |
| A952 Load monitoring warning | Cause: Load conditions on motor indicate belt failure or mechanical fault. Soultion: Check the following: • No breakage, seizure or obstruction of inverter train. • Apply lubrication if required. If using an external speed sensor, check the following parameters for correct function: – P2192 (delay time for permitted deviation) – P2182 (threshold frequency f1) – P2183 (threshold frequency f2) – P2184 (threshold frequency f3) If using a specific torque / speed range, check parameters: – P2182 (threshold frequency 1) – P2183 (threshold frequency 2) – P2184 (threshold frequency 3) – P2185 (upper torque threshold 1) – P2186 (lower torque threshold 1) – P2187 (upper torque threshold 2) – P2188 (lower torque threshold 2) – P2189 (upper torque threshold 3) – P2190 (lower torque threshold 3) – P2192 (delay time for permitted deviation) |
How to Read V20 Faults via BOP & Smart Access Module
While the V20 is a basic drive, diagnostics in 2026 have been streamlined using mobile connectivity. Here is how to access fault data:
- Basic Operator Panel (BOP): The integrated display shows the fault code immediately.
- To view the history, navigate to Parameter r0947 (Fault Code History) and r0949 (Fault Value). These store the last 8 events.
- Smart Access Module (SAM): This is the premier tool for the V20. By attaching this optional Wi-Fi module to the front of the drive, you can use your smartphone or tablet to view a text-based diagnostic dashboard. This eliminates the need to look up codes in a manual, as the phone screen will display “Motor Overcurrent” instead of just “F30001”.
- Parameter Loader: For fleet maintenance, if a drive fails, you can use the SD card or battery-powered parameter loader to transfer settings to a new unit without powering it up.
Frequently Asked Questions (FAQ)
Q: What is the difference between a Fault (F) and an Alarm (A)?
A:
- Fault (Fxxxxx): The inverter switches off, and the motor coasts to a stop. The LED on the drive turns red. You must manually reset this condition.
- Alarm (Axxxxx): The inverter continues to run, but warns of a critical state (e.g., A0501 “Current Limit Reached”). If the condition is not fixed, it will likely escalate to a Fault.
Q: How do I reset a Siemens V20 fault?
A:
- Keypad: Press the OK or FN button on the BOP.
- Digital Input: Pulse the input configured as “Fault Acknowledge” (often DI2 or DI3 depending on the Connection Macro).
- Power Cycle: Turn the drive off and wait for the display to go completely blank.
Q: Why does the drive trip on “F30001” (Overcurrent) at start?
A: This is the most common startup error.
- Ramp Time: The acceleration time (P1120) is too short for the load inertia.
- Motor Data: The motor data entered in P0304-P0311 does not match the nameplate.
- V/f Boost: The voltage boost (P1310/P1311) is set too high, saturating the motor.