40Fault

Felicity inverter error 40 (F40)

CAN data loss

Also displayed as F40 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

CAN data loss — CAN communication 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

IVGM5KL-P1G1

InverterFault

Also applies to:IVGM6KL-P1G1IVGM7K6L-P1G1IVGM8KL-P1G1

What it means

BAT short circuit — Battery port short circuit detected.

Cause: The inverter detected a short circuit — a near-zero-resistance path — across the battery port and shut down to protect the pack and its own power stage.

How to fix it

  1. Check whether the battery port is in short circuit
  2. If the fault still exists, please contact us for help.

Source: Felicitysolar IVGM Series Hybrid inverter Instruction Manual.pdf, p.53

T-REX-3KLP1G01

InverterFault

Also applies to:T-REX-3K6LP1G01T-REX-4KLP1G01T-REX-4K6LP1G01T-REX-5KLP1G01T-REX-6KLP1G01

What it means

Isolation resistance to ground of the PV string is too low

Cause: A fault has been detected in the PV input stage — usually a short, ground fault, or isolation failure between the PV array and the inverter chassis. Wet connectors, damaged cable insulation, or moisture in a junction box are common causes.

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

IVEM 6048

InverterFault

Also applies to:IVEM6048

What it means

CAN 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

CAN data loss

Cause: CAN communication data loss between parallel 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: IVEM8K-12K-II_compressed.pdf, p.44

IVEM8048-LV

InverterFault

Also applies to:IVEM8048

What it means

CAN 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-10KHP3G01

InverterCritical

Also applies to:T-REX-10KLP3G01

What it means

Isolation resistance to ground of the PV string is too low

Cause: A fault has been detected in the PV input stage — usually a short, ground fault, or isolation failure between the PV array and the inverter chassis. Wet connectors, damaged cable insulation, or moisture in a junction box are common causes.

How to fix it

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

Source: T-REX-10KHP3G01-Inverter-User-Guide.pdf, p.29 · T-REX-10KLP3G01-Inverter-User-Guide.pdf, p.28

T-REX-50KHP3G01

InverterFault

What it means

Bus short circuit fault — Bus short, shut down and restart.

Cause: A short circuit was detected on the internal DC bus — bus voltage collapsed while current spiked, which is an internal power-stage fault.

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

Isolation resistance to ground of the PV string is too low

Cause: Isolation resistance to ground of the PV string is too low.

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 40 mean on a Felicity inverter?
It depends on the model — 10 devices use code 40. On the IVPS3524P1G1-LV it means: CAN data loss. The card for each model on this page gives its exact meaning and fix.
Is error 40 a fault or a warning?
40 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 40?
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 IVGM5KL-P1G1

All IVGM5KL-P1G1 codes

Other codes on the T-REX-3KLP1G01

All T-REX-3KLP1G01 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

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.