LLC soft start failure
Also displayed as F37 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:
Also applies to:IVGM6KL-P1G1IVGM7K6L-P1G1IVGM8KL-P1G1
LLC soft start failure — LLC converter soft start failure.
Cause: The LLC converter stage failed to ramp up to its working point during soft start — an internal converter fault rather than a wiring issue.
Source: Felicitysolar IVGM Series Hybrid inverter Instruction Manual.pdf, p.53
Bus undervoltage fault — Bus voltage is too low, shutdown and restart.
Cause: The internal DC bus voltage fell below its operating range. The bus is regulated entirely inside the unit, so a persistent low reading points to an internal conversion-stage fault.
Source: t-rex-25-50khp3g01-user-guide-en.pdf, p.47
Price incl. VATAED 2,801
Price incl. VATAED 2,885
Price incl. VATAED 3,848
Price incl. VATAED 4,984
Price incl. VATAED 17,944
It depends on the model — 2 devices use code 37. On the IVGM5KL-P1G1 it means: LLC soft start failure. The card for each model on this page gives its exact meaning and fix.
37 is a fault code: the inverter cuts its output and the red LED stays solid until it is cleared.
1. Restart the system 2~3 times; 2. The exact steps for each affected model are listed on this page.
37 is in the "Fault" class on the IVGM5KL-P1G1: 61 of the 61 codes documented for it.
37 is in the "Fault" class on the T-REX-50KHP3G01: 105 of the 105 codes documented for it.
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.