When a SHZK 300N frequency drive detects a problem it stops and shows an Err code on the LED display. That code identifies the exact fault — you do not have to guess. Below is the complete Err01 to Err71 fault-code list for the 300N series, with the cause our engineers check first and the corrective action that clears it.
How to read and reset a fault
- Read the code shown on the upper LED display (for example Err14).
- Find it in the table below and correct the cause — do not just reset, or the trip will return.
- After the cause is fixed, press STOP/RST to reset. Some overcurrent faults (see P9-74) require a 5–10 second wait before they can be cleared.
Tip: the drive logs the last three faults in P9-14, P9-15 and P9-16, together with the frequency, current, bus voltage and terminal state at the moment of the trip (P9-17 to P9-44). If a fault is intermittent, read these records before power-cycling — they are cleared on restart.
Complete SHZK 300N fault-code table
| Code | Fault | Likely cause | Corrective action |
|---|---|---|---|
| Err01 | Inverter unit protection | Output short circuit; motor cable too long; module overheating; loose internal wiring; main/drive board or IGBT module fault. | Remove the external short; fit output reactor/filter for long cables; check fan & air duct; re-seat internal cables; otherwise contact support. |
| Err02 | Acceleration overcurrent | Output ground fault/short; vector mode without motor tuning; accel time too short; wrong torque boost or V/F curve; low voltage; starting a spinning motor; sudden load increase. | Clear the short; run motor auto-tuning; lengthen accel time; correct boost/V/F; restore voltage; use speed-tracking start; remove sudden load or upsize the drive. |
| Err03 | Deceleration overcurrent | Output short/ground fault; vector mode without tuning; decel time too short; sudden load increase. | Clear the short; tune the motor; lengthen decel time; remove sudden load; add braking unit & resistor. |
| Err04 | Constant-speed overcurrent | Output short/ground fault; vector mode without tuning; low voltage; sudden load increase. | Clear the short; tune the motor; restore voltage; remove sudden load or upsize the drive. |
| Err05 | Acceleration overvoltage | Input voltage too high; motor driven by external force during accel; accel time too short. | Restore input voltage; remove overhauling load / add brake resistor; lengthen accel time; add braking unit. |
| Err06 | Deceleration overvoltage | Input voltage too high; overhauling load; decel time too short; no braking resistor fitted. | Restore voltage; remove overhauling load; lengthen decel time; install braking unit & resistor. |
| Err07 | Constant-speed overvoltage | Input voltage too high; external force dragging the motor during running. | Restore voltage; remove overhauling load or fit brake resistor. |
| Err08 | Control power supply fault | Input voltage outside the allowed range. | Set input voltage within the specified range. |
| Err09 | Undervoltage | Power dip; input voltage out of range; abnormal bus voltage; rectifier bridge / buffer resistor fault; drive or control board abnormal. | Check supply and restore voltage; for bridge/resistor or board faults contact support. |
| Err10 | Inverter overload | Load too high or motor stalled; drive sized too small. | Reduce load; inspect motor & machinery; upsize the drive. |
| Err11 | Motor overload | P9-01 motor protection gain wrong; load too high or stall; motor too small for drive. | Set P9-01 correctly; reduce load and inspect machinery; upsize. |
| Err12 | Input phase loss | Abnormal 3-phase supply; drive board, lightning-protection board or main board fault. | Fix the supply / peripheral circuit; board faults require support. |
| Err13 | Output phase loss | Drive-to-motor wiring abnormal; unbalanced output; drive board or module fault. | Fix wiring; check the 3 motor windings for balance; board/module faults require support. |
| Err14 | Module overheating | High ambient temperature; blocked air duct; fan damaged; thermistor or IGBT module damaged. | Lower ambient temperature; clean the duct; replace fan; replace thermistor/module. |
| Err15 | External device fault | External fault signal on a multi-function DI terminal or virtual I/O. | Clear the external condition; drive decelerates to stop. |
| Err16 | Communication failure | Host not running; communication cable abnormal; communication parameters (Pd group) wrong. | Check host & wiring; set correct card type and Modbus parameters. |
| Err17 | Contactor fault | Drive board / power supply or contactor malfunction. | Replace drive/power board or contactor. |
| Err18 | Current measurement fault | Hall sensor abnormal; drive board abnormal. | Replace Hall sensor or drive board. |
| Err19 | Motor tuning fault | Motor parameters not entered per nameplate; identification timed out. | Enter correct nameplate data; check drive-to-motor wiring. |
| Err21 | EEPROM read/write fault | EEPROM chip damaged. | Replace the main board. |
| Err22 | Hardware overcurrent/overvoltage | Hardware overvoltage or overcurrent detected. | Follow the overvoltage / overcurrent handling procedures. |
| Err23 | Ground short-circuit fault | Motor shorted to ground. | Replace the cable or motor. |
| Err26 | Run-time reached | Cumulative run time reached the set value. | Use parameter initialization to clear the record. |
| Err27 | User-defined fault 1 | User fault 1 on a DI terminal or virtual I/O. | Clear the condition; drive decelerates to stop. |
| Err28 | User-defined fault 2 | User fault 2 on a DI terminal or virtual I/O. | Clear the condition; drive decelerates to stop. |
| Err29 | Power-on time reached | Cumulative power-on time reached the set value. | Use parameter initialization to clear the record. |
| Err30 | Load-off fault | Running current below the P9-64 threshold. | Check for disconnected load; verify P9-64 / P9-65 match the application. |
| Err31 | PID feedback loss | PID feedback below the PA-26 set value. | Check the feedback sensor/wiring; set PA-26 correctly. |
| Err35 | No data to upload | Drive menu data changed before keyboard copy. | After changing data run P7-23=1 to upload; or set P7-23=0 and press STOP to clear. |
| Err36 | Copy upload overflow | Uploaded content too large. | Reduce the modified menu content. |
| Err37 | Copy upload error | Drive menu data changed. | Set P7-23=0 and press STOP to clear. |
| Err38 | Copy download error | Keyboard contains no uploaded data. | Upload the target machine data first (P7-23=1) and save. |
| Err39 | Dual-core communication fault | Main-board 5 V or drive-board 3.3 V supply abnormal; isolation chip damaged. | Check 5 V and 3.3 V supplies; check/replace the isolation chip. |
| Err40 | Current-limit fault | Load too high / stall; drive sized too small. | Reduce load; inspect machinery; upsize the drive. |
| Err41 | Motor switched while running | Motor switched via terminals while the drive was running. | Switch motors only after the drive is stopped. |
| Err45 | Motor overheating | Temperature-sensor wiring loose; motor temperature too high. | Check sensor wiring; reduce carrier frequency and improve cooling. |
| Err51 | Initial position error | Permanent-magnet motor parameters far from real values; missing phase / motor not connected. | Re-check PM motor parameters (rated current not too low) and motor wiring. |
| Err70 | Low water / pressure protection | Site pressure below the b0-16 water-shortage threshold. | Check b0-16 setting; inspect for a burst pipe or damaged pump. |
| Err71 | Over-pressure protection | Site pressure above the b0-07 limit. | Check b0-07 setting; check for a closed outlet valve or faulty pressure sensor. |
Other display messages that are not faults
- rESEt — shown after you switch motor type in P0-01. It resets in about 2 seconds. If it stays, power the drive off and on.
- tUnE — appears after you start auto-tuning in P1-37; normal, not an error.
- -LOC- — the keypad is locked by P7-24. Hold ENTER for 3 seconds to unlock.
The codes that appear most often — and why
From our production test line and after-sales records, four codes account for the majority of field calls: Err02/03/04 (overcurrent), Err05/06/07 (overvoltage), Err09 (undervoltage) and Err14 (overheating). Overcurrent on a new installation almost always means motor auto-tuning was not run; repeated overvoltage on a fan or pump usually means a braking resistor is missing or undersized. Use the dedicated guides below for the step-by-step fix.
Related Technical Guides
Talk to the engineers who built this drive
Stuck on a fault code, wiring or tuning? Our engineers test every SHZK 300N drive before it ships. Send us your setup and we will reply with the exact fix.