# ABB/FIMER inverter E050 arc fault: what it means and what to do

ABB/FIMER error E050 shows as "AFDD Activated" or "Arc Fault" with the GFI LED. It means the inverter's arc fault protection has detected a possible arc on the DC (solar panel) side and has disconnected from the grid. Because an arc can come from damaged wiring or connectors, have a technician inspect the system before it is reset.

## Common causes

- A possible electric arc on the DC side of the system, meaning the panels, the wiring between them, or the connections to the inverter. ABB's guide says the inverter continuously measures the input current during operation to detect this.

## Safe steps to try

1. **Leave the system as it is** Do not try to reset or restart the inverter. Do not open the inverter, a disconnect, a junction box or any conduit, and do not touch the panels, racking or wiring.
2. **Note the code and when it happened** Write down E050, any other codes, and whether it happened after a storm or any recent work on the roof.
3. **Book a technician** A technician should look for the source of the arc on the DC side before the inverter is reset. If the arc is still present, the inverter's arc sensor self-test will fail again.

## When to call a professional

Call as soon as you see E050. An electric arc is a fire risk, and the inverter will stay disconnected from the grid until it is reset.

## Frequently asked questions

### The manual mentions holding the ESC button. Should I do that?

FIMER's manual says that the first time this happens, holding ESC for five seconds restarts the unit, and that a repeat needs customer assistance. Because an arc can mean damaged wiring, we recommend letting a technician check the DC side first rather than resetting it yourself.

### What is the arc test I see on the display in the morning?

On inverters with arc fault detection, ABB's guide says the inverter runs an arc sensor self-test every time it starts, which is usually each morning when there is enough sunlight. If the test passes, the inverter connects to the grid.

### What is E053?

E053 ("AFDD Fault") means the arc fault board's self-test failed. ABB's guide notes that if a DC arc fault is still present when the self-test runs, the test results in E053.

Canonical page: https://otovo.com/repair/abb/e050