UN-G-F: Grid under frequency

The "Grid Under Frequency" error signals that the frequency of the utility grid is below the acceptable operating range of the inverter. Inverters are designed to operate within specific grid voltage and frequency ranges to ensure safe and efficient energy transfer.

Why it’s problematic

Operating an inverter outside of the grid's specified frequency range can lead to instability, potentially causing the inverter to shut down to protect itself and the grid.
Frequent under-frequency events can indicate problems with the grid's stability and may require attention from the utility company.

Possible causes

Issues with the utility grid: Under-frequency conditions are typically caused by problems within the utility grid itself, such as an imbalance between electricity supply and demand.
Heavy loads on the grid: Increased electricity consumption during peak hours can place a strain on the grid, leading to a drop in frequency.
Grid faults or outages: Faults or outages in the grid infrastructure can disrupt the frequency stability.

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

Monitor the grid frequency: Check the inverter's display for the current grid frequency reading. If it is indeed below the acceptable range, it confirms the under-frequency condition.
Check for local power outages: Inquire with neighbors or check local news sources for any reported power outages or grid disturbances in your area.
Contact your utility company: If the under-frequency condition persists, contact your utility company to report the issue and inquire about any known grid problems or maintenance activities that might be affecting the frequency.
Check inverter settings: On the inverter LCD or under Helios Digital O&M to see the grid frequency. Adjust the settings if the frequency is lower than the local standard.

Verifying the solution

Once the utility company addresses the grid issue, the frequency should stabilize, and the inverter should automatically reconnect to the grid and resume normal operation. You can confirm this by observing the inverter's display, which should indicate a normal grid frequency and the inverter's operating status.

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.