91Fault

Felicity inverter error 91 (F91)

Push-button shutdown alarm

Also displayed as F91 on some models.

Fault — the inverter cuts its output and the red LED stays solid until the fault is cleared.

The exact meaning depends on your model:

IVGM5KL-P1G1

InverterFault

Also applies to:IVGM6KL-P1G1IVGM7K6L-P1G1IVGM8KL-P1G1

What it means

Push-button shutdown alarm — Parallel synchronization signal lost.

Cause: As an alarm this reports the unit being shut down from its power button. The same code number is used in the fault table for loss of the parallel synchronization signal between units, which is why the recommended check is the parallel cabling.

How to fix it

  1. Check whether Parallel cables are firmly and correctly connected
  2. Restart the system 2~3 times
  3. Seek help from us, if can not go back to normal state.

Source: Felicitysolar IVGM Series Hybrid inverter Instruction Manual.pdf, p.52 · Felicitysolar IVGM Series Hybrid inverter Instruction Manual.pdf, p.56

T-REX-10KHP3G01

InverterFault

What it means

The number of battery packs in series has not been set — Number of battery packs in series has not been set.

Cause: The battery configuration is incomplete: the number of battery packs in series was never set, so the inverter cannot map the measured pack voltage to a valid battery range.

How to fix it

Please set it correctly according to the number of battery packs used by the inverter.

Source: T-REX-10KHP3G01-Inverter-User-Guide.pdf, p.29

T-REX-10KLP3G01

InverterFault

What it means

The number of battery packs in series has not been set

Cause: The number of battery packs in series has not been set.

How to fix it

Please set it correctly according to the number of battery packs used by the inverter.

Source: T-REX-10KLP3G01-Inverter-User-Guide.pdf, p.29

T-REX-50KHP3G01

InverterFault

What it means

PV hardware overcurrent fault — PV current is too high, check string current.

Cause: The PV input's hardware overcurrent protection tripped — string current spiked above the trip threshold faster than the software limit reacts.

How to fix it

  1. Power down the inverter, wait 5 minutes for capacitors to discharge, then restart.
  2. If the fault recurs immediately or repeatedly, record the exact code and contact your installer or the manufacturer's service line.

Source: T-REX-50KHP3G01-user-manual-.pdf, p.49

Frequently asked questions

What does error 91 mean on a Felicity inverter?
It depends on the model — 4 devices use code 91. On the IVGM5KL-P1G1 it means: Push-button shutdown alarm. The card for each model on this page gives its exact meaning and fix.
Is error 91 a fault or a warning?
91 is a fault code: the inverter cuts its output and the red LED stays solid until it is cleared.
How do I clear or fix error 91?
1. Check whether Parallel cables are firmly and correctly connected; 2. The exact steps for each affected model are listed on this page.

Related error codes

Other codes on the IVGM5KL-P1G1

All IVGM5KL-P1G1 codes

Other codes on the T-REX-10KHP3G01

All T-REX-10KHP3G01 codes

Other codes on the T-REX-10KLP3G01

All T-REX-10KLP3G01 codes

Other codes on the T-REX-50KHP3G01

All T-REX-50KHP3G01 codes

Prefer the full written guide? Read the complete Felicity inverter error-code guide

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