Quick answer
An ACS355 that trips stops the motor and lights its red LED. The basic control panel shows a fault as F and a four-digit number (for example F0001, OVERCURRENT) and an alarm as A and a number (A2001); the manual's tables list the number alone (0001, 2001). An alarm is a warning; a fault stops the drive until it is reset. Find the code below, fix the cause, then reset with the panel's RESET key, a digital input or the fieldbus, or by switching the supply off for a while.
Jump to a code:
Safety first: lock out and tag out the drive and the machine before you work on the drive, the motor cable or the motor, and follow the Safety chapter of ABB's manual. The intermediate circuit capacitors stay charged after the input power is disconnected: the manual says to always wait 5 minutes; then a qualified person, with a properly rated meter checked on a known source before and after, confirms (a multimeter of at least 1 MΩ impedance, the manual says) that there is no voltage between input terminals U1, V1, W1 and ground and between BRK+ / BRK– and ground – a dark display doesn't mean it's safe. Control circuits fed from outside can stay live with the drive's power off. With a permanent magnet motor, a motor that is still turning feeds voltage back into the drive, so its terminals can be live even with the supply off: stop the motor and lock it against turning, and have a qualified person confirm no voltage on U2, V2, W2 the same way, before any work. Never run insulation (megger) or voltage withstand checks on the drive itself; before a qualified person checks the motor and its cable with power locked out, disconnect the cable from U2, V2, W2. Never bypass Safe Torque Off (STO) or any other safety circuit, and never switch off a fault or turn on automatic resets to keep a machine running – automatic resets restart the drive and the motor after a fault by themselves. Only qualified personnel should work on drives (the manual says qualified electricians), and any measurement on energized equipment follows your site's live-work and arc-flash rules.
Reading and resetting an ACS355 fault
- Note the code. 0401 LAST FAULT holds the latest fault and 0412 / 0413 the two before it; 0404 to 0409 keep the speed, frequency, DC voltage, current, torque and status at the latest fault. The assistant control panel's Fault logger shows more of the history.
- Look it up in the table below or in the manual, and fix the cause first – a fault whose cause is still there comes straight back.
- Reset it: press RESET (EXIT on the basic control panel), use the digital input or fieldbus set in 1604 FAULT RESET SEL, or switch the supply off for a while. Alarms show on the panel only when 1610 DISPLAY ALARMS is set to YES.
- Watch the restart. If the same code returns, go back through the checks before resetting again.
The codes and parameter numbers here are from the ACS355 user's manual; other ABB drive families use their own codes and manuals.
Common ACS355 fault codes
This list covers the codes technicians run into most often, not every code. The manual has the complete list and the full corrective actions.
| Code | What it means | Likely causes | First checks |
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| F0001OVERCURRENTFault | Output current went over the trip level. |
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| F0002DC OVERVOLTFault | The intermediate circuit DC voltage went over the trip limit: 420 V on 200 V drives, 840 V on 400 V drives. |
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| F0003DEV OVERTEMPFault | The drive's IGBT temperature is too high. |
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| F0004SHORT CIRCFault | A short circuit in the motor cable or the motor. |
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| F0006DC UNDERVOLTFault | The intermediate circuit DC voltage is too low. |
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| F0007 / F0008AI1 LOSS / AI2 LOSSFault | An analog input fell below its fault limit (3021 for AI1, 3022 for AI2). |
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| F0009MOT OVERTEMPFault | The motor temperature estimate, or a measured motor sensor, is over the fault limit. |
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| F0010PANEL LOSSFault | The control panel stopped communicating while it was the active control location. |
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| F0012MOTOR STALLFault | The motor is running in its stall region. |
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| F0014 / F0015EXT FAULT 1 / EXT FAULT 2Fault | An external fault input tripped the drive (set in 3003 for fault 1, 3004 for fault 2). |
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| F0016EARTH FAULTFault | The drive found an earth (ground) fault in the motor or the motor cable. |
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| F0017UNDERLOADFault | The motor load is too low, for example a released mechanism in the machine. |
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| F0018THERM FAILFault | The drive's internal temperature thermistor is out of its range. |
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| F0021CURR MEASFault | The drive's current measurement is out of range. |
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| F0022SUPPLY PHASEFault | The DC voltage ripple went over 14 % of nominal, usually from a missing input phase or a blown fuse. |
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| F0024OVERSPEEDFault | The motor turned faster than 120 % of the highest allowed speed. |
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| F0028SERIAL 1 ERRFault | Fieldbus communication broke. |
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| F0034MOTOR PHASEFault | A motor circuit fault: a missing motor phase or a motor thermistor relay fault. |
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| F0035OUTP WIRINGFault | The drive suspects input power is connected to its motor terminals. |
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| F0037CB OVERTEMPFaultWhen 3024 CB TEMP FAULT is enabled | The control board got too hot: 0150 CB TEMP reached 95 °C (102 °C on IP66 drives). |
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| F0044SAFE TORQUE OFFFault | Safe Torque Off was requested and worked; 3025 STO OPERATION is set to answer with a fault. |
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| F0045 / F0046STO1 LOST / STO2 LOSTFault | One STO input channel stayed energized while the other one opened. |
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| F1000PAR HZRPMFault | The speed or frequency limit parameters don't fit together. |
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| A2001OVERCURRENTAlarm | The output current limit controller is active. |
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| A2002OVERVOLTAGEAlarm | The DC overvoltage controller is active. |
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| A2003UNDERVOLTAGEAlarm | The DC undervoltage controller is active. |
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| A2009DEVICE OVERTEMPAlarm | The drive's IGBT temperature is high (the alarm stage before F0003). |
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| A2021 / A2022START ENABLE 1 MISSING / START ENABLE 2 MISSINGAlarm | No Start enable signal (1608 START ENABLE 1, or 1609 for A2022). |
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| A2023EMERGENCY STOPAlarm | The drive received an emergency stop command and ramps down on 2208 EMERG DEC TIME. |
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| A2026INPUT PHASE LOSSAlarm | DC voltage ripple went over 14 % of nominal from a missing input phase or a blown fuse. |
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The name is the message text in ABB's manual; F codes are faults, A codes are alarms. Other faults and alarms in the same chapter that this page doesn't cover: F0011, F0023, F0027, F0029, F0030, F0036, F0101, F0103, F0201–F0204, F0206, F1003–F1007, F1009, F1015, F1017, A2004–A2008, A2010–A2013, A2018, A2019, A2024, A2025, A2029, A2035, A5xxx (control panel alarms) – see the manual for those.
Source: ABB, ACS355 drives User's manual, 3AUA0000066143 Rev E (effective 2020-11-02) – chapter 15, Fault tracing (alarm and fault messages generated by the drive); chapter 1, Safety; actual signals 0107 DC BUS VOLTAGE and group 04 FAULT HISTORY, read on October 17, 2026.
Meanings, causes and checks are summarized in our own words. The manual is the reference: it has every code, the full corrective actions and the safety instructions. A newer revision of the manual may add codes, so check the current revision for your drive.
ACS355 AC drives in stock
ABB ACS355 part numbers on our shelves right now. Every item is photographed, so check the nameplate – catalog number and series – against the drive you're replacing.
- ACS355-01U-07A5-2ABB ACS355-01U-07A5-2 AC Drive VFD 1.5kW 2HP 200-240V 1 Phase Frequency Inverter
- ACS355-03U-05A6-4ABB ACS355-03U-05A6-4+B063 VFD Drive 2.2kW 3HP 380-480V IP66 IP67 NEMA 4X 5.6A
Fault won't clear?
When the checks point to the drive itself – the manual's “replace the drive” – send us the fault code and the catalog number from the nameplate. We check our shelves and our sourcing network and reply with a written quote. Purchase orders are welcome; payment is due before we ship.
Frequently asked questions
How do I reset a fault on an ABB ACS355?
Fix the cause first, then press RESET on the assistant control panel or EXIT on the basic control panel, use the digital input or fieldbus chosen in 1604 FAULT RESET SEL, or switch the supply off for a while. Once the fault is gone the motor can be restarted.
What does F0002 DC OVERVOLT mean on an ACS355?
The intermediate circuit (DC bus) voltage went over the trip limit – 420 V on 200 V drives and 840 V on 400 V drives. When it happens while slowing down, the usual causes are a deceleration time that is too short, the overvoltage controller (2005) switched off, or a faulty or undersized brake chopper. Read 0107 DC BUS VOLTAGE on the panel.
What is the difference between an F code and an A code on an ACS355?
An F code is a fault: the drive stops and stays stopped until it is reset. An A code is an alarm: a warning, for example a current or voltage controller working at its limit; many alarms have a fault with the same cause.
Where can I see which faults an ACS355 had?
0401 LAST FAULT holds the latest fault and 0412 PREVIOUS FAULT 1 and 0413 PREVIOUS FAULT 2 the ones before it; 0404 to 0409 keep the drive's speed, frequency, DC voltage, current, torque and status at the latest fault. The assistant control panel's Fault logger mode shows up to ten faults.
Can you supply a replacement ACS355 drive?
Send the type code from the rating plate (for example ACS355-03U-...) and the fault code through our quote form. We check our shelves and our sourcing network and reply with a written quote.