SolarEdge V-String Too High Message – Troubleshooting &... | solarfaults.org

Technical Background:

The SolarEdge inverter is designed to monitor the voltage of each string connected to it. When the voltage exceeds the maximum input threshold, typically due to overvoltage conditions, the inverter triggers the V-String Too High fault. This can occur from a variety of factors, including incorrect string configurations, shading effects causing unequal voltage distribution, or faulty modules. The inverter continuously performs insulation resistance testing (RISO) and ground fault detection to ensure safety and compliance with the National Electrical Code (NEC).

Symptoms:

Homeowners may observe a shutdown of the inverter accompanied by a V-String Too High message in the monitoring app. The inverter's LED indicators may flash irregularly or remain off. Additionally, there may be a noticeable drop in energy production, as the inverter is unable to process the excess voltage.

Possible Causes:

Overvoltage from the solar array due to excessive string configuration or shading conditions.
Incorrectly sized or damaged cables leading to increased resistance and voltage drops.
Faulty or misconfigured solar modules causing irregular voltage outputs.
Poor grounding or loose connections in the junction box affecting the voltage readings.
Inadequate inverter settings not aligned with the actual array configuration.
Temperature effects on module performance, leading to voltage increases beyond inverter limits.

Solution:

1

Use a multimeter to measure the voltage at the string terminals to verify if the output exceeds the inverter's maximum input voltage limit.
2

Inspect all wiring connections for signs of corrosion, damage, or looseness, particularly in the junction box and at the inverter input.
3

Check the configuration of the solar array to ensure the number of modules in series does not exceed the inverter's specifications.
4

If overvoltage is detected, consider reconfiguring the array to reduce the string length or replace any faulty modules.
5

Verify that the inverter settings match the actual solar array configuration using the manufacturer's monitoring app or interface.
6

Inspect the grounding system to ensure it is intact and properly connected.
7

Document and maintain records of all measurements and adjustments for future reference.

Safety Warning:

Always consult a licensed electrician or certified solar installer when performing electrical work to ensure safety and compliance with local codes.

Prevention:

To avoid future occurrences of the V-String Too High error, regularly inspect the solar array configuration and ensure it aligns with the inverter's specifications. Schedule routine maintenance checks to identify potential issues with modules, wiring, and grounding. Additionally, monitor environmental conditions that may affect module performance, such as shading from nearby trees or structures.

Frequently Asked Questions

•What does the V-String too high message indicate?

The V-String too high message indicates that the voltage of the string exceeds the inverter's limits, causing a shutdown to protect the system.

•How can I troubleshoot this issue?

To troubleshoot, check the string voltage with a multimeter and ensure it is within the inverter's specified range. Inspect for any faulty panels or connections.

SolarEdge V-String Too High Message – Troubleshooting & Technical Fix Guide

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Frequently Asked Questions

•What does the V-String too high message indicate?

•How can I troubleshoot this issue?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention: