storagefaults.comstoragefaults.com

Analysis by Marcus & Team

SolarEdge: Troubleshooting "Grid Lost" Error with Main Breaker On

Diagnosing SolarEdge "Grid Lost" error when the main breaker is on. Troubleshoot grid synchronization, voltage fluctuations, and inverter faults.

Frequently Asked Questions

•What is the expected lifespan of a SolarEdge inverter?

SolarEdge inverters typically have a 12-year standard warranty, extendable to 20 or 25 years. Actual lifespan depends on environmental conditions and usage patterns.

•How can I check the current firmware version of my SolarEdge inverter?

The firmware version is usually displayed on the SolarEdge monitoring portal or through the inverter's display panel (if equipped). Refer to the user manual for specific instructions.

•What are the recommended surge protection devices for a SolarEdge system?

SolarEdge recommends installing surge protection devices (SPDs) on both the AC and DC sides of the inverter to protect against voltage transients caused by lightning or other events. Consult with a qualified electrician to select appropriate SPDs based on your location and electrical system characteristics.

Related questions

Loading related questions...

Marcus leads the technical research department at Storage Faults. Together with a team of systems analysts, he specializes in translating complex solar storage error codes into actionable diagnostic steps for the US market.

← Back to list

Technical Background:

SolarEdge hybrid inverters use sophisticated algorithms to synchronize with the grid (60Hz AC). This includes voltage and frequency matching, and power factor correction. Anti-islanding protection is mandated by UL 1741 to prevent the inverter from energizing the grid during an outage, which poses safety hazards for utility workers. The inverter continuously monitors grid voltage, frequency, and impedance. If these parameters deviate beyond pre-set limits (e.g., voltage outside +/- 5%, frequency outside +/- 0.5 Hz), the inverter will disconnect from the grid and report a "Grid Lost" error.

Symptoms:

The SolarEdge inverter reports a "Grid Lost" error despite the main AC breaker supplying the house being in the ON position, and other household AC loads functioning normally. The inverter ceases exporting power to the grid, and may switch to battery backup mode (if a battery is installed).

Possible Causes:

Grid voltage fluctuations: Brief voltage sags or surges beyond the inverter's operating window.
Grid frequency instability: Temporary deviations in grid frequency outside acceptable limits.
AC wiring issues: Loose connections or high resistance in the AC wiring between the inverter and the main breaker panel.
Faulty grid impedance measurement: Inverter incorrectly detecting grid impedance issues.
Inverter firmware glitches: Software errors causing false "Grid Lost" detection.
Anti-islanding protection malfunction: Overly sensitive anti-islanding circuitry.

Solution:

1

Visually inspect the AC wiring between the inverter and the main breaker panel for any loose connections or signs of damage. A qualified electrician should tighten all connections to the specified torque.
2

Using a calibrated multimeter, measure the AC voltage at the inverter's AC input terminals. Compare these readings to the voltage at the main breaker panel. Significant voltage drops indicate wiring problems.
3

Monitor the grid voltage and frequency using the SolarEdge monitoring portal or a power quality analyzer. Check for voltage sags, surges, or frequency deviations coinciding with the "Grid Lost" errors.
4

Verify the inverter's firmware is up to date. Outdated firmware can contain bugs that cause false "Grid Lost" errors. Consult the SolarEdge documentation for the correct update procedure.
5

Check the inverter's event log for any other error codes that might provide clues to the root cause of the problem.
6

If the problem persists, contact a SolarEdge certified installer or service provider. They have access to advanced diagnostic tools and can perform more in-depth troubleshooting.
7

As per NEC 705.43, ensure proper labeling of the PV system disconnects and breakers.

Safety Warning:

Working with electrical equipment involves the risk of electric shock and arc flash. Always de-energize the AC and DC circuits before performing any maintenance or troubleshooting. Follow proper lockout/tagout procedures. High DC voltages (up to 600V or more) are present in the PV system. NEC Article 690 provides specific guidance for safe PV system systems and maintenance. Only qualified electricians should perform work on electrical systems.

Prevention:

Regularly check the SolarEdge monitoring portal for any error messages or performance anomalies. Ensure the inverter's firmware is kept up to date. Schedule periodic inspections of the AC wiring by a qualified electrician to check for loose connections or corrosion. Maintain clear communication with your utility company regarding any planned grid maintenance that might affect voltage or frequency stability.

Expert Tip:

Access the SolarEdge inverter's service menu (refer to the system manual for the key combination – often involves pressing specific buttons in sequence) and check the real-time grid voltage, frequency, and impedance readings. Compare these readings to the values displayed on the monitoring portal. Discrepancies may indicate sensor calibration issues within the inverter.