Sinamics V20 Fault Codes: F80, F2, F3, F4, A922 Explained
Sinamics V20 Fault Codes: F80, F2, F3, F4, and A922 Explained
The Sinamics V20 is a compact, no-nonsense drive. When something goes wrong, it talks to you in fault codes. Five codes come up constantly in the field: F80 (motor stall/overcurrent), F2 (overvoltage), F3 (undervoltage), F4 (drive overtemperature), and A922 (a warning rather than a hard fault). Knowing which one you have and why it tripped gets the line back up faster than guessing.
Quick Answer
F80 is a motor-blocking or motor-stall fault—the drive detected excessive current draw with little or no shaft movement, usually caused by a mechanical jam, an undersized drive, or incorrect motor parameters. Clear it by removing the mechanical load, verifying P0304–P0311 motor data, and—after LOTO, identifying, and correcting the root cause—resetting with the OK button or a digital input assigned to reset. The other common V20 faults (F2 overvoltage, F3 undervoltage, F4 overtemperature, A922 warning) each have distinct electrical or environmental root causes covered below.
⚠️ Safety First
Lock out and tag out (LOTO) before opening the drive enclosure or touching wiring. The DC bus capacitors on a Sinamics V20 retain lethal voltage after power is removed—wait at least five minutes after disconnecting AC power before touching internal components. Never clear a fault and restart without first identifying and correcting the root cause; repeated faults can mask a progressive failure and cause equipment damage or injury.
F80 | Motor Blocked / Motor Stall
F80 is the fault most techs see first. The drive is trying to accelerate but current is pegged and the motor isn't moving—or is moving too slowly relative to the setpoint.
Common causes
- Mechanical jam: conveyor, pump, or fan seized or heavily loaded at start
- Motor data mismatch: nameplate parameters (P0304–P0311) entered incorrectly
- Drive undersized for the application—confirm drive current rating covers motor FLA plus starting current
- V/Hz tuning incorrect for the load type
- Stall detection thresholds set too aggressively for the application—exact parameter names and numbers vary by firmware version; consult the V20 parameter manual for your revision
How to clear F80
- LOTO the machine. Physically verify the load is free to rotate.
- Power the drive back up (if safe). Navigate to the fault buffer and note any sub-fault value displayed—this gives the operating condition at trip time.
- Check motor nameplate against P0304 (rated voltage), P0305 (rated current), P0307 (rated power), P0310 (rated frequency), and P0311 (rated speed). Correct any mismatch.
- Run the quick commissioning wizard again if parameters were changed.
- Consider running a motor identification routine if load characteristics are uncertain—the exact parameter and procedure for motor identification vary by firmware revision; consult the V20 commissioning section of your operating instructions.
- Press OK on the BOP to acknowledge, or pulse the digital input wired to "fault reset."
- Restart at low speed and monitor current draw on the BOP or via r0027.
Pro tip: After clearing F80, watch r0027 (output current) during the next start. If current spikes to near drive rated current before the shaft gets moving, your acceleration ramp (P1120) is too short for the load inertia. Extend the ramp time before the next trip happens.
F2 | DC Bus Overvoltage
F2 trips when the DC link voltage climbs above the drive's overvoltage threshold. The most common cause is regenerative energy—a fast deceleration ramp forces energy back into the bus and the capacitors can't absorb it all.
Common causes
- Deceleration ramp (P1121) too short for the load inertia
- Supply voltage running high—measure incoming line voltage at the drive terminals
- No braking resistor on a high-inertia load (flywheel, centrifuge, large fan)
- Overvoltage controller not enabled or not tuned—the relevant parameter name and number vary by firmware version; consult the V20 parameter manual for your revision
Fix it
Extend P1121 (decel ramp time) first—that alone clears 70% of F2 faults in the field. If the load demands fast stops, install a braking resistor and enable the dynamic braking channel. Verify incoming line voltage is within the drive's rated supply tolerance.
F3 | DC Bus Undervoltage
F3 is the opposite of F2. The DC bus dropped below the minimum threshold during operation.
Common causes
- Supply voltage dip or brownout during heavy load start
- Loose or corroded line-side terminal connection—resistance causes voltage drop under load
- Undersized supply transformer or long cable run to the drive
- Phase loss on a three-phase supply (single-phasing condition)
- Kinetic buffering or ride-through not enabled for the application—the relevant parameter name and number vary by firmware version; consult the V20 parameter manual for your revision
Fix it
Measure supply voltage at the drive input terminals—not upstream at the panel. Voltage measured at the panel breaker and voltage measured at the drive terminals can differ significantly on a long cable run or with a poor connection. Torque all line-side terminals to the specification listed in the installation manual for your specific V20 frame size. Check for phase loss with a multimeter across each phase pair.
F4 | Drive Overtemperature
F4 means the drive's internal temperature sensor hit the shutdown threshold. The drive is protecting itself from thermal damage.
Common causes
- Ambient temperature above the drive's rated maximum—check the spec for your frame size
- Blocked or failed cooling fan (larger V20 frames have an internal fan)
- Enclosure airflow insufficient—drives packed too close together, no ventilation
- Drive running continuously at or above rated current for extended periods
- Dirty heatsink fins clogged with dust or oil mist
Fix it
Let the drive cool before resetting. Don't just clear and restart—find the heat source. Check the enclosure temperature with an IR thermometer. Inspect heatsink fins and clean if clogged. Verify minimum clearances above and below the drive are maintained per the installation manual. If ambient is the problem, add a panel air conditioner or upgrade to a drive rated for higher ambient. Check the internal fan for blade rotation and proper airflow direction.
Pro tip: A V20 running F4 faults seasonally—fine in winter, tripping in summer—almost always has an enclosure airflow problem, not a drive problem. The drive isn't failing; the panel is too hot. Add ventilation before condemning the hardware.
A922 | Warning (Not a Hard Fault)
A922 is an alarm, not a fault. The drive keeps running but it's telling you something is degraded or a parameter configuration is incomplete. The exact meaning of A922 is context-dependent—it commonly appears as a motor data identification warning or a configuration advisory, but alarm text and precise definitions can vary between firmware releases. Cross-reference A922 in the V20 operating instructions for your specific firmware version before acting on assumptions about its cause.
What to do with A922
- Read the alarm detail on the BOP. Some firmware revisions display a sub-code or additional text on the second line.
- Check whether motor identification has been completed. An incomplete or failed identification run is a common A922 trigger—refer to the commissioning section of your operating instructions for the correct procedure.
- Review the parameter set for any recently changed values—A922 can flag incomplete commissioning.
- Consult the Siemens support site for your exact firmware version's alarm list to confirm the specific cause before proceeding.
A922 won't stop the drive, but ignoring it long-term hides the underlying misconfiguration. Address it during the next maintenance window.
Fault Code Quick Reference
| Code | Type | Meaning | First Check |
|---|---|---|---|
| F80 | Fault (trip) | Motor blocked / stall | Mechanical jam; motor parameters |
| F2 | Fault (trip) | DC bus overvoltage | Decel ramp too short; regen energy |
| F3 | Fault (trip) | DC bus undervoltage | Supply dip; loose terminal; phase loss |
| F4 | Fault (trip) | Drive overtemperature | Ambient temp; blocked airflow; dirty heatsink |
| A922 | Warning (runs) | Configuration / identification advisory | Motor ID status; commissioning completeness |
Common Problems After Clearing the Fault
- Fault comes back immediately on restart: The root cause is still present. Don't just keep resetting—diagnose first. A drive that trips within seconds of reset has a real hardware or mechanical problem.
- BOP shows fault but no fault code: Power cycle the drive fully. Occasional display glitches happen; a true fault will re-display after power cycle.
- Fault reset not working via digital input: Verify the digital input is configured for the fault reset function and the signal is pulsing, not held high. Many firmware versions require a rising edge to reset—exact parameter names and assignment procedures vary by firmware revision; consult your V20 parameter manual.
- Multiple faults appearing simultaneously: Check the fault buffer (accessible via the BOP or commissioning tool). The first fault in the buffer is the root cause—later faults are usually consequences of the first trip.
- F80 after motor swap: New motor almost always means new nameplate data. Re-enter all P030x parameters and rerun motor identification.
When to Replace the Drive
Most F2, F3, F4, and F80 faults are application or wiring problems—not drive failures. But some situations point to hardware that's done:
- F4 trips with ambient temperature well within spec and heatsink clean—internal temperature sensor or IGBT degradation
- F3 trips with solid, in-spec supply voltage—internal rectifier or capacitor degradation
- F80 trips with correct motor data and free-spinning load—output IGBT asymmetry causing uneven phase current
- Physical signs: burn marks, capacitor bulging, cracked PCB traces, burned terminals
- Drive has accumulated years of continuous service in a hot or dirty environment—capacitors have a finite life
⚡ Need a tested replacement?
PLC Department stocks tested Siemens Sinamics V20 drives and a broad range of Siemens automation hardware—all inspected, backed by a 1-year warranty, and available for same-day shipping from Texas.
Shop Siemens Drives →For the official Siemens fault code list and firmware-specific alarm documentation, search the Siemens Industry Support portal for "Sinamics V20 Operating Instructions" and select your firmware version. The fault value (sub-code) displayed alongside the fault code on the BOP is your fastest path to the specific cause—always note it before clearing.
Disclaimer: This guide is provided for general information only. Procedures vary by model, series, and firmware version. Industrial equipment can cause serious injury, equipment damage, or downtime if serviced incorrectly. Always consult the manufacturer's official documentation and a qualified professional before performing work, and follow your facility's lockout/tagout and safety procedures. PLC Department is an independent surplus supplier and is not affiliated with or endorsed by the manufacturers referenced. Use this information at your own discretion.
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