Voltronic Otima II Tower Error Codes: Causes & Fixes (12 codes)

This is the complete fault table for the Voltronic Otima II Tower ups — all 12 codes from the official manual on one page. On this Voltronic device, a fault code means the unit has entered protection and stopped normal operation; a warning leaves it running. The exact indication (LED pattern or display code) is listed per code below.

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

Fault(12)— operation stops until cleared

Fault codes (12)operation stops until cleared

Bus start fail.

Fault

Fault code 01 shown on the display; the UPS has detected a fault condition: Bus start fail.

CauseBus start fail.

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

Source:OtimaII-Tower-1K-5K-manual.pdf· page 14

Bus over.

Fault

Fault code 02 shown on the display; the UPS has detected a fault condition: Bus over.

CauseBus over.

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

Source:OtimaII-Tower-1K-5K-manual.pdf· page 14

Bus under.

Fault

Fault code 03 shown on the display; the UPS has detected a fault condition: Bus under.

CauseBus under.

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

Source:OtimaII-Tower-1K-5K-manual.pdf· page 14

Inverter soft start fail.

Fault

Fault code 11 shown on the display; the UPS has detected a fault condition: Inverter soft start fail.

CauseInverter soft start fail.

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

Source:OtimaII-Tower-1K-5K-manual.pdf· page 14

Inverter voltage high.

Fault

Fault code 12 shown on the display; the UPS has detected a fault condition: Inverter voltage high.

CauseInverter voltage high.

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

Source:OtimaII-Tower-1K-5K-manual.pdf· page 14

Inverter voltage Low.

Fault

Fault code 13 shown on the display; the UPS has detected a fault condition: Inverter voltage Low.

CauseInverter voltage Low.

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

Source:OtimaII-Tower-1K-5K-manual.pdf· page 14

Inverter output short.

Fault

Fault code 14 shown on the display; the UPS has detected a fault condition: Inverter output short.

CauseInverter output short.

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

Source:OtimaII-Tower-1K-5K-manual.pdf· page 14

Battery voltage too high.

Fault

Fault code 27 shown on the display; the UPS has detected a fault condition: Battery voltage too high.

CauseBattery voltage too high.

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

Source:OtimaII-Tower-1K-5K-manual.pdf· page 14

Battery voltage too low.

Fault

Fault code 28 shown on the display; the UPS has detected a fault condition: Battery voltage too low.

CauseBattery voltage too low.

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

Source:OtimaII-Tower-1K-5K-manual.pdf· page 14

Over temperature.

Fault

Fault code 41 shown on the display; the UPS has detected a fault condition: Over temperature.

CauseOver temperature.

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

Source:OtimaII-Tower-1K-5K-manual.pdf· page 14

Over load.

Fault

Fault code 43 shown on the display; the UPS has detected a fault condition: Over load.

CauseOver load.

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

Source:OtimaII-Tower-1K-5K-manual.pdf· page 14

Charger failure.

Fault

Fault code 45 shown on the display; the UPS has detected a fault condition: Charger failure.

CauseCharger failure.

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

Source:OtimaII-Tower-1K-5K-manual.pdf· page 14

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Common questions about Otima II Tower error codes

What is the difference between a fault and a warning on the Otima II Tower?: A fault puts the unit into protection and stops normal operation — this page lists 12 of them for the Otima II Tower. The Otima II Tower manual defines no separate warning table — every listed code stops operation. Resolve the cause of a fault before restarting; warnings can usually be cleared while the unit runs.
Does this page apply to other Voltronic models?: No — this table was transcribed specifically from the Otima II Tower manual. Other Voltronic devices have their own pages; start from the error-code hub to find the one matching the model number on your unit's label.
Where do these codes come from?: Every entry was transcribed from OtimaII-Tower-1K-5K-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.