AL 4 / Err 4
(Mains Phase Loss)

One phase on the input is missing or unbalanced. Drive will trip if a phase drop persists.

Input power issue or blown input fuse. Possible faulty AC line contactor, or input rectifier assembly.

Check incoming power: Measure all three input phases with a voltmeter. Look for a blown input fuse or failed rectifier (power board). Replace input fuse or rectifier board if bad. Ensure all input wires are tight. Wake Industrial stocks replacement AC input modules and fuses.

AL 7 / Err 7
(DC Link Overvoltage)

Drive DC bus voltage is too high (above limit). Often appears as “OVERVOLT”.

Overvoltage usually occurs when regenerative energy (motor acting as generator) feeds the bus. A failed braking transistor or fan can cause heat. Possible part: braking chopper / resistor or DC bus capacitor issue.

Check braking unit and mains: Inspect brake resistor and chopper board. Make sure input voltage is correct and stable. If DC bus caps are bulging or old, replace the DC link capacitors or the brake components. Also check if cooling fan failed (overheat can bias the DC bus). For parts, Wake Industrial carries DC capacitors, brake modules, and complete power boards.

AL 8 / Err 8
(DC Link Undervoltage)

DC bus voltage is too low (below limit). Drive trips.

Caused by low input voltage or excess load. Could be bad rectifier diodes or a failing control supply.

Check AC input and fan: Verify AC supply is stable. Inspect the input rectifier diodes (power board) and replace if shorted. Test the drive’s internal 10 V control supply. A bad power board or weak DC link caps may undercharge the DC bus – consider replacing the power-stage board or large electrolytic capacitors.

AL 9 / Err 9
(Inverter Overload / Inverter Time)

Drive is close to overloading. Usually a flashing alarm before trip.

Drive delivers near 100% duty cycle. Possible causes: too heavy a load, incorrect current settings, or failing IGBTs. Part: power-stage / inverter board.

Reduce load & inspect: Ensure the motor isn’t overloaded. Check setting Motor Thermal (par 128). For a faulting drive, test IGBT modules on the inverter board. Replace the inverter board or entire power stack if IGBTs are bad. Wake Industrial can supply refurbished inverter modules or full drive replacements.

AL 10 / Err 10
(Motor Overload / Motor Time)

Motor temperature overload – often amber warning then trip.

The motor is overheating, possibly due to excessive load or stall. Not a drive part fault, but sometimes misconfigured motor data or a burned-out cooling fan (on some drives).

Inspect motor & settings: Check motor nameplate data. Verify mechanical load isn’t too high. If the drive trips with “Motor time”, reset the thermal settings or let the motor cool. If internal drive fans exist, ensure they run. No Danfoss drive part usually fails here; focus on motor and parameter correction. Contact Wake Industrial for replacement motors/drives.

AL 12
(Current Limit Warning)

Drive output current hit programmed limit, shows as warning or trip “CURRENT LIMIT”.

This is a warning, often from excessive load or a short. Motor parameters or wiring errors cause output current spikes.

Check wiring & params: Ensure motor wiring is correct. Adjust parameter Par 221 (max current) or reduce load. If the drive won’t start even at low load, check the current sensor (shunt) circuit on the power board. Replacement current-sense boards or shunt resistors can be ordered from Wake Industrial.

AL 13 / Err 13
(Overcurrent)

Peak current exceeded (trip). The drive’s output surged 200%+. Red LED blinks.

Often due to a motor-phase short or sudden torque spike. Could be a shorted IGBT in the inverter or a faulty diode in the rectifier.

Inspect output stage: Check motor insulation and wiring for shorts. Measure IGBTs on the inverter board – replace inverter IGBT modules if one is shorted. Also inspect DC link caps (an exploding cap can cause spikes). Wake Industrial can help source spare IGBT modules, rectifier boards, and new capacitors. Reset the drive after replacing failed components.

AL 14 / Err 14
(Ground Fault / Earth Fault)

Drive senses leakage to ground. Occurs when output is shorted to earth/ground.

A motor phase is shorted to ground, or an output transistor has failed. Possible failed part: power IGBT or a shorted capacitor.

Find the ground short: Disconnect the motor and test drive output (U/V/W phases) to ground. If the fault clears with motor disconnected, the motor is at fault. If not, likely the drive’s power board has a short (replace IGBTs or DC link caps). 

AL 16 / Err 16
(Short Circuit)

Line-to-line short on output. Drive tripped immediately.

Phase-to-phase short in the motor or wiring, or within the inverter. IGBT failure often causes this.

Check motor and wire: Inspect motor terminals and cables for a short. If external wiring is fine, test the inverter board. Replace the entire power board (rectifier+inverter assembly) if necessary. Use Wake Industrial’s inventory for refurbished boards or drives to minimize downtime.

AL 29 / Err 36
(Drive Overtemperature)

Power board (heat sink) exceeded safe temp.

Overheated power components (IGBTs) or clogged heatsink/fan. Likely causes: dead fan, blocked airflow, or ambient temp too high.

Cool it down: Check that all fans are spinning and heatsinks are clean. Replace any failed fans or heat sinks. Ensure the drive’s environment is within spec. If the drive itself is damaged by heat, swapping in a replacement power module or board is recommended.

AL 30,31,32 / Err 30-32
(Missing Phase U/V/W)

Drive detects an open phase on motor output. This only appears when running (not at start).

Typically a loose or broken output wire, or open-circuit in a phase. On drives with removable phase terminals, a loose connector can cause this. Rarely, a failed IGBT can make one phase output open.

Inspect motor wiring: Power off and tighten all motor wires. Inspect connectors for corrosion. If one phase still “missing” with a new motor, the drive’s inverter IGBTs might be faulty in that leg. Replace the power/inverter module or IGBTs on that phase.

AL 15
(Hardware Mismatch)

Non-compatible option installed.

Drive detects an option card (like brake or serial comm card) that isn’t recognized or fitted correctly.

Reseat or replace option: Check that any accessory (e.g. brake control, communication card) matches the drive model. Reseat or remove the card. If the drive itself is mis-flagged, updating firmware or swapping the logic board (available from Wake Industrial) may help.

AL 2
(Live Zero Error)

Analog input signal missing or out-of-range. (Occurs if Live Zero Timeout is enabled.)

A 4–20mA or 0–10V command signal from a PLC or control is lost.

Check control signal: Verify the analog input wiring and source. If the input board is faulty, replace the I/O / control PCB. Wake Industrial stocks common Danfoss I/O boards and rebuilt drives with functioning analog inputs.

AL 17
(STD Bus Timeout)

Serial comms with an accessory (like LCP keypad) lost.

Faulty cable or dead control panel (LCP).

Test the LCP / cable: Swap in a known-good keypad. If communication resumes, replace the faulty LCP display unit. If not, check the comm. board or logic card.

Other Codes (50–58, 80)
(AMA/Auto-tune Fail, Reset)

Automatic Motor Adaptation failures or drive reset. Alarm 80 means “Drive initialized” (parameters defaulted).

Usually no hardware fault – just re-tuning issues or config. A drive reset (80) just means settings were lost.

Follow procedure: For AMA errors, ensure the motor is correctly wired and sized for auto-tune. If alarm 80 appears unexpectedly, re-enter parameters from backup. For a persistent fault, replacing suspect memory or flash (on the control PCB) may be needed.