Drives (VFD) troubleshooting answers
44 questions with answers cited from the manufacturer manuals.
- 0WEG CFW500 F0051: IGBT overtemperature, what to check first?
The F0051 fault indicates that the power module's internal temperature sensor (P0030) has reached its overtemperature trip level, which varies by inverter model and frame. An A0050 alarm will appear 5 °C below this trip …
- 0WEG CFW500 trips F0074 at start or while running, what to check?
Fault F0074 on a WEG CFW500 inverter indicates a ground overcurrent, meaning an overcurrent from an output phase to ground (PE). This protection acts instantly in hardware to cut output pulses. It can occur at start or w…
- 0WEG CFW500 trips F0072 (Motor Overload) after a motor change, why?
Fault F0072 indicates that the inverter's motor overload function (Ixt) has detected excessive winding heating, estimated by integrating the output current above the set overload current. This can happen during sustained…
- 0WEG CFW500 trips F0070 instantly at start, even with no load, what to check?
The F0070 fault on a WEG CFW500 inverter indicates an overcurrent or short circuit on the output, DC link, or braking resistor. An instant trip at start, especially with no load, strongly suggests a short circuit in the …
- 0WEG CFW500 trips F0022 on deceleration, what to check?
The F0022 fault on a WEG CFW500 inverter indicates that the DC link voltage has exceeded its maximum allowed level for the configured supply. This often happens during deceleration, especially with high-inertia loads, as…
- 0WEG CFW500 trips F0021 at power-up, what to check?
The F0021 fault on a WEG CFW500 inverter indicates that the DC link voltage has dropped below its minimum threshold for the configured supply. This can happen due to issues with the incoming power supply, incorrect volta…
- 0ATV320 PHF fault under load, what to check first?
A PHF fault on a Schneider Altivar ATV320 drive indicates an input phase loss, meaning one supply phase is missing or the drive is incorrectly supplied. This protection only activates when the drive is under load. It's d…
- 0ATV320 OLF fault after long run, what to check first?
The OLF fault on a Schneider Altivar ATV320 indicates that the drive's internal motor thermal protection has tripped due to excessive motor current. This typically occurs after extended periods of high load, repeated sta…
- 0ATV320 USF fault, supply undervoltage, what to check first?
The USF fault on a Schneider Altivar ATV320 drive indicates a supply mains undervoltage. This can be caused by the supply voltage being too low, transient voltage dips, or the loss of two or three input phases. The error…
- 0ATV320 OBF fault during deceleration, what to check?
An OBF fault on a Schneider Altivar ATV320 drive indicates a DC bus overvoltage. This typically occurs during deceleration, with an overhauling load, or if the supply voltage is too high. Since the fault only appears dur…
- 0ATV320 trips SCF3 at start, after washdown, what to check?
An SCF3 fault on a Schneider Altivar ATV320 drive indicates a significant earth leakage current at the drive's output. This fault often occurs at start-up or while running, especially with multiple motors connected to on…
- 0ATV320 SCF1 instantly on run command, after motor work: what to check?
An SCF1 fault on a Schneider Altivar ATV320 drive indicates a motor short circuit or grounding at the drive's output. This can occur instantly at the run command, especially after recent work on the motor or cables. The …
- 0ATV320 OCF trip during acceleration of a high-inertia load, what to check?
An OCF (Overcurrent) fault on a Schneider Altivar ATV320 drive indicates that the drive detected excessive output current. This often occurs during acceleration of high-inertia loads, on a load step, or after a motor or …
- 0Danfoss FC 302 Alarm 29: Heat Sink Temp after running loaded, what to check?
Alarm 29 on a Danfoss VLT FC 302 indicates that the maximum heat sink temperature has been exceeded. This alarm will not reset until the heat sink cools down below a defined temperature, with trip and reset points varyin…
- 0Danfoss FC 302 Alarm 10: Motor ETR Overtemp, what to check?
Alarm 10 on a Danfoss VLT FC 302 indicates that the drive's electronic thermal protection (ETR) calculates the motor is too hot, likely due to running with more than 100% overload for an extended period. This can be conf…
- 0Danfoss FC 302 trips Alarm 9 after running loaded for a while, why?
Alarm 9 (Inverter Overload) on a Danfoss FC 302 indicates the drive has operated above 100% overload for an extended period, causing its electronic thermal inverter protection counter to reach 100%. The drive cannot be r…
- 0Danfoss FC 302 Alarm 4: what to check for mains phase loss?
Alarm 4 on a Danfoss VLT FC 302 indicates a missing phase on the supply side or excessive mains voltage imbalance. This alarm can also appear due to a fault in the input rectifier. It typically occurs while the drive is …
- 0Danfoss FC 302 trips A8 DC Undervoltage at power-up, what to check?
Alarm 8 on a Danfoss VLT FC 302 indicates that the DC-link voltage has dropped below its undervoltage limit. If no 24 V DC back-up supply is connected, the drive will trip after a fixed delay that varies with unit size. …
- 0Danfoss FC 302 trips A7 on ramp-down, what to check?
Alarm 7 (DC Overvoltage) on a Danfoss VLT FC 302 indicates the DC-link voltage exceeded its limit, causing the drive to trip. This typically occurs when the motor regenerates energy back to the drive faster than it can b…
- 0Danfoss FC 302 Alarm 14: what to check first for an earth fault?
Alarm 14 on a Danfoss VLT FC 302 indicates an Earth (Ground) Fault, meaning current is flowing from an output phase to ground. This can occur in the motor cable or the motor itself. The drive detects this by comparing th…
- 0Danfoss FC 302 trips A13 during ramp-up, what to check?
Alarm 13 (Overcurrent) on a Danfoss VLT FC 302 indicates the output current has exceeded the inverter's peak current limit, which is approximately 200% of the drive's rated current. This alarm is typically preceded by a …
- 0GA500 oH Heatsink Overheat: what to check first?
The GA500 oH fault indicates the heatsink temperature has exceeded the level set in L8-02. This often points to high ambient temperatures, insufficient cooling, or a heavy load. The drive will stop as configured by L8-03…
- 0Yaskawa GA500 oL1 after running a while, output current above FLA: what to check?
The oL1 fault on a Yaskawa GA500 drive indicates a motor overload, meaning the drive's electronic thermal motor protection has tripped. This fault can only be reset once the motor overload level (U4-16) is below 100. Com…
- 0Yaskawa GA500 trips GF at startup, what to check first?
A Yaskawa GA500 Ground Fault (GF) indicates a current short to ground on the output side of the drive, exceeding 50% of the drive's rated current. This fault can be triggered by damaged motor insulation, a shorted motor …
- 0GA500 Uv1 fault on a conveyor, what to check first?
A Uv1 fault on a Yaskawa GA500 drive indicates a DC Bus Undervoltage, meaning the DC bus voltage dropped below the level set in L2-05 while the drive was operating. This typically occurs when the input power supply is un…
- 0GA500 trips ov fault during deceleration, what to check?
An 'ov' overvoltage fault on a Yaskawa GA500 drive indicates the DC bus voltage exceeded its detection level, typically 410V for 200V class or 820V for 400V class drives. This often occurs during deceleration due to rege…
- 0Yaskawa GA500 trips oC instantly at start, even unloaded: what to check?
An oC fault on a Yaskawa GA500 drive indicates that the output current exceeded the specified overcurrent detection level. An instant trip at start, especially when unloaded, strongly suggests an issue with the motor cab…
- 0SINAMICS G120 A07910: Motor overtemperature alarm, what to check?
The SINAMICS G120 A07910 alarm indicates that the motor's measured temperature (KTY sensor) or thermal model has exceeded the alarm threshold (p0604), or a PTC/bimetal contact has responded. This is an alarm, not a fault…
- 0SINAMICS G120 F07900: Motor blocked on start, what to check?
The F07900 fault on a SINAMICS G120 indicates the motor has operated at its torque limit for longer than the configured delay time (p2177) while remaining below the speed threshold (p2175). This often points to a mechani…
- 0SINAMICS G120 CU240E-2 F07801 at start, what to check first?
The F07801 fault on a SINAMICS G120 drive indicates that the permissible motor limit current was exceeded. This often occurs at start, during acceleration, or on a load step. Common causes include switching onto a rotati…
- 0SINAMICS G120 trips F30005 after running a while, what to check?
Fault F30005 on a SINAMICS G120 indicates that the Power Module has been overloaded, meaning its I2t value (r0036) reached 100%. This typically happens when the permissible rated current is exceeded for too long or the l…
- 0SINAMICS G120 CU240E-2 F30003 during running, what to check?
Fault F30003 on a SINAMICS G120 indicates that the Power Module has detected an undervoltage condition in the DC link and has shut down. This can occur during operation if the supply voltage dips or fails, during brownou…
- 0SINAMICS G120 F30002 during ramp-down, what to check?
A SINAMICS G120 F30002 fault indicates a DC link overvoltage, meaning the Power Module detected too much voltage and tripped. This often happens during ramp-down, especially with high-inertia loads, due to regenerated en…
- 0SINAMICS G120 F30001 instantly at power-on, r0949=1: what to check?
Fault F30001 on a SINAMICS G120 indicates an overcurrent detected by the Power Module, causing an OFF2 trip. The fault value r0949 helps identify the phase involved, with bit 0 corresponding to phase U. An instant trip a…
- 0PowerFlex 525 F081 DSI Comm Loss: what to check first?
The F081 DSI Comm Loss fault on a PowerFlex 525 drive indicates an interruption in communication between the drive and its Modbus or DSI master device. This fault is a Type 2 fault, and its response is determined by para…
- 0PowerFlex 525 F033 Auto Rstrt Tries: what to check first?
Fault F033 on a PowerFlex 525 drive indicates that the drive attempted to reset a fault and resume operation for the configured number of attempts (A541 [Auto Rstrt Tries]) but failed. This is a Type 2 fault, meaning it …
- 0PowerFlex 525 F013 Ground Fault after washdown, what to check?
A PowerFlex 525 F013 Ground Fault indicates the drive detected a current path to earth ground at one or more of its output terminals. This fault can occur at start, during operation (especially after washdown or cable mo…
- 0PowerFlex 525 F012 HW OverCurrent instantly at start, what to check?
The F012 HW OverCurrent fault on a PowerFlex 525 drive indicates the output current exceeded the hardware limit. This is a Type 2 fault, meaning it won't clear with an auto-restart. An instant trip at start, especially w…
- 0PowerFlex 525 F007: motor overload trips after a few minutes, what to check?
The F007 Motor Overload fault on a PowerFlex 525 drive indicates that the drive's internal electronic motor overload protection (I²t, Class 10) has tripped. This occurs when the output current remains above the configure…
- 0PowerFlex 525 F005 OverVoltage on decel, what to check?
A PowerFlex 525 drive trips F005 (OverVoltage) when the DC bus voltage exceeds its maximum value. This often occurs during deceleration, especially with high-inertia or overhauling loads, or due to high line voltage. The…
- 0PowerFlex 525 F004 UnderVoltage when large loads start, what to check?
Fault F004 on a PowerFlex 525 indicates that the DC bus voltage has dropped below the drive's minimum threshold. This is a Type 1 fault, meaning it can be cleared by an auto-restart. Common causes include supply dips, lo…
- 0ACS580 trips 3220 DC Link Undervoltage, what to check first?
The ACS580 drive trips with a 3220 DC Link Undervoltage fault when the DC link voltage falls too low during modulation. This can be caused by a missing supply phase, a blown fuse, or a fault in the rectifier bridge. If t…
- 0ACS580 trips Fault 3210 during deceleration, what to check?
Fault 3210 indicates that the drive's intermediate-circuit (DC link) voltage has risen too high, causing the drive to trip. This commonly occurs when the motor regenerates energy during deceleration or with an overhaulin…
- 0ABB ACS580 trips Fault 2310 instantly at start, what to check?
Fault 2310 (Overcurrent) on an ABB ACS580 drive indicates the output current exceeded its internal limit. While a heavy load or fast acceleration can cause this, an instant trip at start, especially with no load, points …