What is the difference between a fault and a warning on the Axpert VM II (PF1)?

A fault cuts the unit's output and the red LED stays solid — this page lists 16 of them for the Axpert VM II (PF1). A warning only flashes the red LED and the unit keeps running; there are 8 warning codes here. Resolve the cause of a fault before restarting; warnings can usually be cleared while the unit runs.

Which model numbers does this page cover?

The Axpert VM II (PF1) shares its firmware and fault table with 1 other model number: Axpert VM II 3KVA PF1, Axpert VM II 5KVA PF1. If your unit is any of these, every code on this page applies to it.

Where do these codes come from?

Every entry was transcribed from Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf — Voltronic's official documentation. Each row cites its source manual (and page where printed), so you can verify the wording before acting on it.

Voltronic Axpert VM II (PF1) Error Codes: Causes & Fixes (24 codes)

This is the complete fault table for the Voltronic Axpert VM II (PF1) Inverter family — 24 codes shared by 2 model numbers, transcribed from the official manual. On Voltronic units, a fault code means the unit has cut its output and the red LED stays solid; a warning flashes the red LED while the unit keeps running.

Also coversAxpert VM II 3KVA PF1Axpert VM II 5KVA PF1

Last checked against the official manuals on July 27, 2026.

Fault(16)— output stops · red LED solid
Warning(8)— unit keeps running · red LED flashing

Fault codes (16)output stops · red LED solid

Fan is locked when inverter is off.

Fault

Fault code 01 shown on the display with the fault icon on: Fan is locked when inverter is off..

CauseFan fault.

Recommended fixReplace the fan.

Source:Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 28Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 33

Over temperature or NTC is not connected well.

Fault

Fault code 02 shown on the display with the fault icon on: Over temperature or NTC is not connected well..

CauseInternal temperature of inverter component is over 100°C.

Recommended fixReturn to repair center.

Source:Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 28Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 33

Battery voltage is too high.

Fault

Fault code 03 shown on the display with the fault icon on: Battery voltage is too high.

CauseBattery is over-charged.

Recommended fixReturn to repair center.

Source:Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 28Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 33

Battery voltage is too low.

Fault

Fault code 04 shown on the display with the fault icon on: Battery voltage is too low.

CauseBattery voltage is too low.

Recommended fixRestart the unit. If the fault happens again, contact your installer or the repair centre.

Source:Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 28

Output short circuited or over temperature is detected by internal converter components.

Fault

Fault code 05 shown on the display with the fault icon on: Output short circuited or over temperature is detected by internal converter components..

CauseOutput short circuited.

Recommended fixCheck if wiring is connected well and remove abnormal load.

Source:Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 28Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 33

Output voltage is too high.

Fault

Fault code 06 shown on the display with the fault icon on: Output voltage is too high..

CauseOutput abnormal (Inverter voltage below than 190Vac or is higher than 260Vac).

Recommended fix1. Reduce the connected load. 2. Return to repair center.

Source:Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 28Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 33

Overload time out.

Fault

Fault code 07 shown on the display with the fault icon on: Overload time out.

CauseOverload error. The inverter is overload 105% and time is up.

Recommended fixReduce the connected load by switching off some equipment.

Source:Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 28Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 33

Bus voltage is too high.

Fault

Fault code 08 shown on the display with the fault icon on: Bus voltage is too high.

CauseInternal components failed.

Recommended fixReturn to repair center.

Source:Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 28Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 33

Bus soft start failed.

Fault

Fault code 09 shown on the display with the fault icon on: Bus soft start failed.

CauseInternal components failed.

Recommended fixReturn to repair center.

Source:Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 28Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 33

Over current or surge.

Fault

Fault code 51 shown on the display with the fault icon on: Over current or surge.

CauseOver current or surge.

Recommended fixRestart the unit, if the error happens again, please return to repair center.

Source:Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 28Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 33

Bus voltage is too low.

Fault

Fault code 52 shown on the display with the fault icon on: Bus voltage is too low.

CauseBus voltage is too low.

Recommended fixReduce the number of PV modules in series.

Source:Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 28Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 33

Inverter soft start failed.

Fault

Fault code 53 shown on the display with the fault icon on: Inverter soft start failed.

CauseInternal components failed.

Recommended fixReturn to repair center.

Source:Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 28Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 33

Over DC voltage in AC output.

Fault

Fault code 55 shown on the display with the fault icon on: Over DC voltage in AC output.

CauseOutput voltage is unbalanced.

Recommended fixReduce the number of PV modules in series.

Source:Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 28Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 33

Current sensor failed.

Fault

Fault code 57 shown on the display with the fault icon on: Current sensor failed.

CauseInternal components failed.

Recommended fixReturn to repair center.

Source:Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 28Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 33

Output voltage is too low.

Fault

Fault code 58 shown on the display with the fault icon on: Output voltage is too low.

CauseOutput abnormal (Inverter voltage below than 190Vac or is higher than 260Vac).

Recommended fix1. Reduce the connected load. 2. Return to repair center.

Source:Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 28Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 33

PV voltage is over limitation.

Fault

Fault code 59 shown on the display with the fault icon on: PV voltage is over limitation.

CausePV input voltage is beyond the specification.

Recommended fixReduce the number of PV modules in series.

Source:Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 28Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 33

Warning codes (8)unit keeps running · red LED flashing

W01

Fan is locked when inverter is on.

Warning

Warning code 01 flashing on the display: Fan is locked when inverter is on.. Audible alarm: beep three times every second.

CauseFan is locked when inverter is on.

Recommended fixReplace the fan.

Source:Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 28

W02

Over temperature.

Warning

Warning code 02 flashing on the display: Over temperature.

CauseOver temperature.

Recommended fixReturn to repair center.

Source:Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 28

W03

Battery is over-charged.

Warning

Warning code 03 flashing on the display: Battery is over-charged. Audible alarm: beep once every second.

CauseBattery is over-charged.

Recommended fixReturn to repair center.

Source:Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 28

W04

Low battery.

Warning

Warning code 04 flashing on the display: Low battery. Audible alarm: beep once every second.

CauseLow battery.

Recommended fixThe unit keeps operating. Clear the condition shown and the warning resets automatically; if it persists, contact your installer or the repair centre.

Source:Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 28

W07

Overload.

Warning

Warning code 07 flashing on the display: Overload. Audible alarm: beep once every 0.5 second.

CauseOverload.

Recommended fixReduce the connected load by switching off some equipment.

Source:Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 28

W10

Output power derating.

Warning

Warning code 10 flashing on the display: Output power derating. Audible alarm: beep twice every 3 seconds.

CauseOutput power derating.

Recommended fixThe unit keeps operating. Clear the condition shown and the warning resets automatically; if it persists, contact your installer or the repair centre.

Source:Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 28

W15

PV energy is low.

Warning

Warning code 15 flashing on the display: PV energy is low.. Audible alarm: beep twice every 3 seconds.

CausePV energy is low.

Recommended fixThe unit keeps operating. Clear the condition shown and the warning resets automatically; if it persists, contact your installer or the repair centre.

Source:Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 28

W16

High AC input (>280VAC) during BUS soft start.

Warning

Warning code 16 flashing on the display: High AC input (>280VAC) during BUS soft start.

CauseHigh AC input (>280VAC) during BUS soft start.

Recommended fixThe unit keeps operating. Clear the condition shown and the warning resets automatically; if it persists, contact your installer or the repair centre.

Source:Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf· page 28

Still seeing a code on your Axpert VM II (PF1)?

Send us the code on your screen and a Voltronic technician will reply with the exact steps for your unit. Support is free for life — a first diagnosis never needs a callout.

Message a technician on WhatsApp Call +971542899793 or use the contact form

Keep troubleshooting

Related devices

Common questions about Axpert VM II (PF1) error codes

What is the difference between a fault and a warning on the Axpert VM II (PF1)?: A fault cuts the unit's output and the red LED stays solid — this page lists 16 of them for the Axpert VM II (PF1). A warning only flashes the red LED and the unit keeps running; there are 8 warning codes here. Resolve the cause of a fault before restarting; warnings can usually be cleared while the unit runs.
Which model numbers does this page cover?: The Axpert VM II (PF1) shares its firmware and fault table with 1 other model number: Axpert VM II 3KVA PF1, Axpert VM II 5KVA PF1. If your unit is any of these, every code on this page applies to it.
Where do these codes come from?: Every entry was transcribed from Axpert-VM-II-PF1-USB-dry-contact-100A_manual.pdf — Voltronic's official documentation. Each row cites its source manual (and page where printed), so you can verify the wording before acting on it.

Compiled from official Voltronic user manuals. Always consult your device manual and a qualified technician before performing repairs.

How to read the severity labels

Fault codes (16)output stops · red LED solid

Fan is locked when inverter is off.

Over temperature or NTC is not connected well.

Battery voltage is too high.

Battery voltage is too low.

Output short circuited or over temperature is detected by internal converter components.

Output voltage is too high.

Overload time out.

Bus voltage is too high.

Bus soft start failed.

Over current or surge.

Bus voltage is too low.

Inverter soft start failed.

Over DC voltage in AC output.

Current sensor failed.

Output voltage is too low.

PV voltage is over limitation.

Warning codes (8)unit keeps running · red LED flashing

Fan is locked when inverter is on.

Over temperature.

Battery is over-charged.

Low battery.

Overload.

Output power derating.

PV energy is low.

High AC input (>280VAC) during BUS soft start.

Still seeing a code on your Axpert VM II (PF1)?

Keep troubleshooting

Related devices

Common questions about Axpert VM II (PF1) error codes