SINAMICS V20 Fault Codes: What Do F1, F2, F3 and A501 Mean?
What SINAMICS V20 F fault and A alarm codes mean, their likely cause, first check and how to clear them, based on the official Siemens instructions.
What do F and A codes mean on a SINAMICS V20 display? Codes starting with F are faults and codes starting with A are alarms. F1 is overcurrent, F2 overvoltage and F3 undervoltage. A501 is a current limit warning. Faults are cleared by acknowledging them; alarms cannot be acknowledged and clear by themselves once the cause is gone. The tables below are written in our own words from the Siemens SINAMICS V20 operating instructions (A5E34559884-015, 05/2022, pages 341-353). They apply to the V20 series only; series such as G120 and S120 use different codes.
Before touching the drive
Siemens states that a hazardous voltage can remain for up to 5 minutes after power off because of the capacitors. Switch off, wait 5 minutes, confirm by measurement that the unit is dead, then start work. Work on the power circuit must be done by qualified electrical staff.
SINAMICS V20 fault codes
| Code | Meaning | Possible cause | First check |
|---|---|---|---|
| F1 | Overcurrent | P0307 does not match converter power r0206, motor lead short circuit, earth fault | Motor data, cable length, short circuits and earth faults; P0350, blocked motor. If needed raise P1120 and lower P1312 |
| F2 | Overvoltage | Mains voltage too high or motor regenerating | Voltage P0210, ramp-down time P1121, Vdc control P1240; braking resistor if needed |
| F3 | Undervoltage | Mains failed or shock load | Supply voltage |
| F4 | Converter overtemperature | Overload, poor ventilation, high pulse frequency, ambient temperature, fan fault | Load, P0307/r0206, default pulse frequency, ambient and fan |
| F5 | Converter I2t | Overload or demanding load cycle | Load cycle and P0307/r0206. It cannot be cleared until r0036 is below P0294 |
| F6 | Chip temperature rise | High start-up load, load step, fast ramp | Load, P1120, P0307/r0206; P0290 = 0 or 2 prevents it |
| F11 | Motor overtemperature | Overload; on small motors below 15 Hz it can occur with a normal temperature | Load, P0626-P0628, P0604. If current and real temperature are normal, set P0335 = 1 |
| F12 | Temperature signal lost | Heat sink sensor wire broken | The manual lists no separate action; service |
| F20 | DC ripple too high | Usually a lost input phase | Mains wiring |
| F23 | Output current ripple too high | Missing output phase or high motor vibration | Output wiring, motor vibration, P0296 |
| F35 | Auto restart limit exceeded | Attempts exceeded P1211 | Cause of the repeating fault |
| F41 | Motor data identification failure | Per r0949: no load, current limit, or stator resistance out of range | Motor connection, P0304-P0311, star/delta wiring |
| F51 | Parameter EEPROM fault | Read/write failure or full EEPROM | Power cycle, then factory reset P0970 = 31 and parameterise again |
| F52 | Converter software fault | Converter data unreadable or invalid | Power cycle; if it stays, service or replace |
| F60 | Asic timeout | Internal communication failure; if sporadic, possibly EMC | Converter, EMC measures and EMC filter |
| F61-F64 | SD card parameter cloning faults | Card, file or converter type mismatch | FAT16/FAT32 card, /USER/SINAMICS/DATA folder, compatible converter. F64 only clears by a power cycle |
| F70 | I/O extension module communication | No connection to the module | Refit, check and acknowledge; replace if it stays |
| F71 / F72 | No USS or Modbus setpoint | No setpoint within telegram time | RS232 or RS485 master |
| F80 | Analog input signal lost | Broken wire or signal out of range | Analog input wiring |
| F85 | External fault | Triggered through control word 2 bit 13 | P2106 and the command source |
| F100 / F101 | Software or processor error | Watchdog reset, stack overflow | Service or replace the converter |
| F200 | Script error | Internal program stopped | Correct the script |
| F221 / F222 | PID feedback out of range | Feedback below P2268 / above P2267 | Limits and feedback gain |
| F350 | Configuration vector failed | Hardware does not match the vector; r0949 = 13 wrong power module | Correct power module. Acknowledge with a power cycle only |
| F395 | Acceptance test pending | Parameters may have changed after a startup clone | Check parameters and confirm by clearing the fault |
| F410 | Cavitation protection | Not enough flow in the pump | Sensor, P2361 and protection delay |
| F452 | Load monitoring trip | Belt failure or mechanical fault | Drive train, lubrication, P2182-P2192 |
SINAMICS V20 alarm codes
| Code | Meaning | Possible cause | First check |
|---|---|---|---|
| A501 | Current limit | Motor power mismatch, long motor leads, earth fault; very small (120 W) motor under FCC | F1 checks; use V/f for very small motors |
| A502 | Overvoltage limit | During ramp down with P1240 = 0 | If permanent, the input voltage |
| A503 | Undervoltage limit | Mains failed or r0026 below the limit | Mains voltage |
| A504 | Converter overtemperature warning | Heat sink or chip at warning level | Ambient, load and fan; r0037 |
| A505 | Converter I2t warning | Warning level exceeded | Load cycle |
| A506 | IGBT temperature rise warning | Heat sink to IGBT difference too high | Load steps and shock loads |
| A507 | Temperature signal lost | Sensor may have fallen off | Service or replace the converter |
| A511 | Motor I2t warning | Overload or heavy cycles | P0604, P0625, rating plate data, P0344; P1900 = 2 if needed |
| A523 | Output current ripple | Lost output phase or motor vibration | Output wiring and motor |
| A535 | Braking resistor overload | Braking energy too high or resistor unsuitable | Reduce braking energy or use a higher rated resistor |
| A541 | Motor identification active | P1900 selected | Identification may be running |
| A910 | Vdc_max deactivated | High mains, driving load, very high inertia | Input voltage, load, braking resistor if needed |
| A911 | Vdc_max active | DC bus being held at the limit | Mains and P1121 |
| A912 | Vdc_min active | DC bus below r1246 | Motor energy is used through short mains dips |
| A921 | Analog output set wrongly | P0777 and P0779 identical | Set different values |
| A922 | No load on the converter | Motor may not be connected | Motor connection |
| A923 | JOG right and left together | P1055 and P1056 both requested | Do not press both |
| A930 | Cavitation warning | See F410 | F410 checks |
| A936 | PID autotuning active | P2350 | Clears when tuning ends |
| A952 | Load monitoring warning | See F452 | F452 checks |
How do you clear a fault?
Acknowledge the code from the panel on the fault screen, or externally if the converter is set up that way. An uncleared fault returns to the screen after 60 seconds without a key press. F350 and F64 only clear by a power cycle, and F5 will not clear until r0036 is below P0294.
Products this table applies to
The table covers the V20 series, for example 6SL3210-5BB21-5UV1 and 6SL3210-5BB22-2UV1. See variable frequency drives for replacements, braking resistors for F2 and A535, and the frequency inverter selection guide for sizing.
Frequently asked questions
Does V20 A501 mean overload?
No. A501 is a current limit warning. The converter I2t warning is A505 and the motor I2t warning is A511. Some sources online mix these up.
What should you check first for F1?
Motor power P0307 must match converter power r0206. Then check the motor cable, earth faults and whether the motor is blocked. After that, raise ramp-up time P1120 or lower starting boost P1312.
Why does F11 appear on a cold motor?
Small motors running below 15 Hz can trip F11 even with a normal temperature. If motor current is within the rating plate and the real temperature is normal, Siemens says to set P0335 = 1.
Does F2 need a braking resistor?
Check the voltage, ramp-down time P1121 and Vdc control P1240 first. High inertia needs longer ramps; if that is not possible, use a braking resistor.