42Fault

Felicity inverter error 42 (F42)

Synchronization data loss

Also displayed as F42 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:

IVPS3524P1G1-LV

InverterFault

Also applies to:IVPS5048P1G1-LVIVPS7548P2G1IVPS10048P2G1IVPS3.5~10kVA-USIVPS3-5-10KVA

What it means

Synchronization data loss — Synchronization data is lost between inverters in the parallel system.

Cause: Parallel communication cables between inverters are loose, damaged or not connected well.

How to fix it

  1. Check if the communication cables are connected well and restart the inverter.
  2. If the problem remains, contact your installer.

Source: IVPS3524P1G1-LV IVPS5048P1G1-LV IVPS7548P2G1 IVPS10048P2G1 User Guide - EN.pdf, p.25

T-REX-3KLP1G01

InverterFault

Also applies to:T-REX-3K6LP1G01T-REX-4KLP1G01T-REX-4K6LP1G01T-REX-5KLP1G01T-REX-6KLP1G01T-REX-10KHP3G01T-REX-10KLP3G01

What it means

Relay check failure

Cause: A safety relay inside the inverter has failed self-test or is stuck. The inverter is designed to refuse grid connection in this state, so this is not an issue you can clear with restart cycles.

How to fix it

Restart the unit, if the error persists, contact the repair center.

Source: T-REX-3_3.6_4_4.6_5_6KLP1G01-hybrid-inverter-user-guide-English.pdf, p.38 · T-REX-10KHP3G01-Inverter-User-Guide.pdf, p.29 · T-REX-10KLP3G01-Inverter-User-Guide.pdf, p.29

IVEM 6048

InverterFault

Also applies to:IVEM6048

What it means

Synchronization data loss

Cause: Communication cable connection issue between paralleled inverters.

How to fix it

  1. Check if communication cables are connected well and restart the inverter
  2. If the problem remains, please contact your installer.

Source: felicitysolar IVEM 6048 Solar Inverter User Guide.pdf, p.38

IVEM8048-II

InverterFault

Also applies to:IVEM12048-IIIVEM 8K-12K Series II

What it means

Synchronization data loss

Cause: Synchronization data loss in parallel communication.

How to fix it

  1. Check if communication cables are connected well and restart the inverter
  2. If the problem remains, please contact your installer.

Source: IVEM8K-12K-II_compressed.pdf, p.44

IVEM8048-LV

InverterFault

Also applies to:IVEM8048

What it means

Synchronization data loss

Cause: Communication failure between paralleled inverters.

How to fix it

  1. Check if communication cables are connected well and restart the inverter
  2. If the problem remains, please contact your installer.

Source: FelicitySolar IVEM8048-LV Single Phase Hybrid Inverter User Guide.pdf, p.39

T-REX-50KHP3G01

InverterFault

What it means

Balanced Bridge Overcurrent Fault — Balanced bridge current is too high, shutdown and restart.

Cause: Current in the bus-balancing bridge tripped the hardware overcurrent protection, which acts independently of the firmware — a fast current spike in the circuit that keeps the two bus halves matched.

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.47

Apollo-5KLP1G01-MX

Energy storage systemCritical

Also applies to:Apollo-5KLP1G01-M1Apollo-5KLP1G01-M2Apollo-4K6LP1G01-MXApollo-4K6LP1G01-M1Apollo-4K6LP1G01-M2

What it means

Relay check failure — Relay self-check failure.

Cause: Relay check failure.

How to fix it

Restart the unit, if the error persists, contact the repair center.

Source: Apollo-5KLP1G01-All-in-one-ESS-User-Guide.pdf, p.44

Frequently asked questions

What does error 42 mean on a Felicity inverter?
It depends on the model — 9 devices use code 42. On the IVPS3524P1G1-LV it means: Synchronization data loss. The card for each model on this page gives its exact meaning and fix.
Is error 42 a fault or a warning?
42 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 42?
Check if the communication cables are connected well and restart the inverter. If the problem remains, contact your installer. The exact steps for each affected model are listed on this page.

Related error codes

Other codes on the IVPS3524P1G1-LV

All IVPS3524P1G1-LV codes

Other codes on the T-REX-3KLP1G01

All T-REX-3KLP1G01 codes All T-REX-10KHP3G01 codes All T-REX-10KLP3G01 codes

Other codes on the IVEM 6048

All IVEM 6048 codes

Other codes on the IVEM8048-II

All IVEM8048-II codes

Other codes on the IVEM8048-LV

All IVEM8048-LV 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.