DC-INTF: DC overcurrent

The "DC-INTF" error indicates that the inverter is detecting an excessive current flow from the solar panels on the DC side of the system.

Why it's problematic

High currents can damage the inverter's internal components, leading to permanent failure.
Overcurrent conditions pose a safety hazard and increase the risk of fire or electrical shock.

Possible causes

Short circuit in the PV array: A short circuit in a solar panel or the wiring connecting the panels can cause a sudden surge in current.
Ground fault: A ground fault, where a live conductor comes into contact with the grounding system, can also result in high currents.
Faulty wiring or connections: Damaged, corroded, or loose wiring connections in the DC circuit can lead to increased resistance and higher current flow.
Oversized PV array: A PV array that exceeds the inverter's maximum input current rating can cause persistent overcurrent conditions.

Before you begin

Safety First: Working with electrical equipment always involves risks. Ensure you are qualified and follow appropriate safety precautions. Disconnect the inverter from both AC and DC sources before performing any physical inspection or adjustments.

Gather Information: Before starting troubleshooting, have the inverter manual on hand. You should also gather information about the inverter model and serial number, the installation date, and the PV array configuration (number of panels, capacity, and number of strings).

Troubleshooting steps

Check for visible damage: Inspect the PV array, wiring, and connections for any signs of physical damage, such as burnt or melted components, exposed wires, or loose connections.
Isolate the faulty string: If the inverter has multiple DC inputs, systematically disconnect each string to identify the one causing the overcurrent. If the error clears after disconnecting a specific string, that string needs further investigation.
Inspect wiring and connections: Carefully check the wiring and connections within the faulty string, looking for loose connections, corrosion, or signs of damage. Tighten loose connections, clean or replace corroded parts, and repair or replace damaged wiring.
Test the PV array: Use a multimeter to check the voltage and current output of each solar panel in the faulty string. Compare the readings to the manufacturer's specifications to identify any panels with abnormal output. A shorted panel will show very low or zero voltage.
Verify array sizing: Ensure that the PV array's total current output does not exceed the inverter's maximum DC input current rating. If the array is oversized, it may need to be reconfigured or a larger capacity inverter may be required.

Verifying the solution

After addressing the identified problem, reconnect the DC inputs and observe the inverter's display. The error should clear, and the inverter should resume normal operation. You can confirm this by checking the inverter's output parameters, such as DC current and voltage, which should be within the acceptable range.

If the problem is not resolved

If the error persists after following all the above steps, there might be an internal fault within the inverter.

As a system owner: In this case, contact the inverter installer or distributor for further assistance. You can find the details of your installer in the MyAutarco app.
As a certified installer: Contact Autarco Support, you can submit a support case via Helios.