OV_DC: DC Over Voltage

The "DC Over Voltage" error means the DC input voltage from the solar strings exceeds the inverter's limits.

Why it's problematic

High DC voltage can damage the inverter, potentially leading to costly repairs or replacements.
It presents a serious safety hazard due to the high electrical potential.

Possible causes

Excessive solar irradiation: Under extremely sunny conditions, the solar panels may produce more voltage than usual, triggering the error.
Too many solar panels in series: If the combined voltage of the panels in a string exceeds the inverter's maximum input voltage, a DC overvoltage error will occur.
Incorrect solar array configuration or wiring: Mistakes in the wiring or configuration of the solar array can result in improper voltage levels being sent to the inverter.
Faulty solar panels: A malfunctioning solar panel could generate abnormally high voltage, exceeding the inverter's limits.

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

Restart the inverter (up to three times). This simple step can sometimes resolve temporary glitches or communication errors.
Check the inverter's display for the specific error code related to DC overvoltage. This code can provide more detailed information about the nature of the problem.
Check for loose or damaged DC connectors. Make sure the connectors are properly seated and that there is no damage to the wiring or terminals. If the DC inputs are accidentally reversed or the inverter is not working properly, do not turn off the DC switch, as this could damage the inverter. Instead, you should wait until solar irradiance is reduced and confirm with a clip-on ammeter that the string current is below 0.5A. Only then is it safe to turn off the DC switches and disconnect the PV strings.
If the error code indicates a specific string, disconnect and reconnect that string one by one. This helps pinpoint the source of the overvoltage.
Measure the string voltage using a multimeter. Compare the reading with the inverter's displayed voltage and the maximum input voltage specified in the inverter's manual.
If the measured voltage is indeed too high, check the solar array configuration. Ensure that the number of panels in series does not exceed the maximum allowed for the inverter.
Inspect the solar panels in the affected string for any signs of damage or malfunction. Look for cracks, discoloration, or hotspots on the panels.

Verifying the solution

Once the troubleshooting steps are complete, monitor the inverter's display. If the "DC Over Voltage" error disappears and the DC voltage readings are within the acceptable range, the problem is likely resolved. The inverter should resume normal operation, and the green LED indicator should be on continually. You can further confirm this by observing the inverter's power generation.

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: 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.