Okay, let's break down your situation with the SolarEdge HD-Wave 11.4 inverters on a closed Delta high-leg system and the over-voltage faults.1. High-Leg Compatibility and Setup SolarEdge Inverters ARE Compatible with High-Leg Delta Systems

SolarEdge inverters are generally designed to handle high-leg delta configurations. However, correct configuration is crucial for proper operation.

Critical Configuration Items to Check (Most Likely Culprits)



Grid Profile/Country Setting

This is the

most likely cause of your problem. The inverter's grid profile must be configured for the specific voltage, frequency, and grid standards of the US, and specifically one that allows for high-leg delta systems. If it's set to a profile that expects a symmetrical voltage (e.g., a Wye grid profile), it will see the high leg as over-voltage. "Grid Type" or similar setting

Some SolarEdge inverters have a specific setting to select the grid type (Wye, Delta, High-Leg Delta). Look for this in the inverter's configuration menus. Selecting "High-Leg Delta" or similar is essential.

Neutral Connection (if applicable)

Even though it's a closed Delta (no neutral), check if the inverter's AC wiring instructions explicitly require a neutral connection, even for monitoring purposes. If so, and it's not connected, that could lead to issues. In some cases, a grounded neutral may be required at the service. Verify the installation.

Firmware Version

Make sure the inverters have the latest (or at least a relatively recent) firmware. Older firmware might have bugs related to high-leg Delta systems. SolarEdge often pushes firmware updates automatically, but it's worth checking.

How to Check These Settings (Generally)



SolarEdge SetApp

This is the primary way to configure SolarEdge inverters. Technicians use a smartphone app (SetApp) that connects wirelessly to the inverter. You'll need a SolarEdge installer account to access the advanced settings.

SolarEdge Monitoring Portal

The monitoring portal might allow you to view (but not change) some of the basic configuration settings. You'll need the installer's credentials to access this.

2. Increasing High Voltage Set Point Restricted Access

Increasing the high voltage ride-through (HVRT) set point on SolarEdge inverters is generally a restricted function. SolarEdge wants to prevent people from arbitrarily raising voltage thresholds in a way that could compromise grid safety and compliance.

How to Potentially Access



Advanced Commissioning Tool

SolarEdge has an "Advanced Commissioning Tool" (ACT) that provides deeper access to inverter settings, including voltage ride-through. However, this tool is highly restricted and typically only available to certified SolarEdge installers who have undergone specific training.

SolarEdge Support

Your best option is to contact SolarEdge support directly. Explain the situation, provide the inverter serial numbers, and explain why you believe the voltage set point needs adjustment. They may be able to remotely adjust the settings or provide you with temporary access to the ACT. Be prepared to provide data logs and explain your reasoning thoroughly. They will require verification that you are a qualified electrician.

Why This is Difficult

SolarEdge takes grid compliance very seriously. They don't want inverters to operate outside of specified voltage ranges. They will be very hesitant to grant access to change these settings unless you can provide a compelling technical justification.

IMPORTANT CAUTION

Messing with voltage set points can have serious consequences. You could damage the inverter, compromise grid stability, and potentially violate regulations.

Troubleshooting Steps (Before Adjusting Voltage Set Point)

Before even thinking about raising the voltage set point, go through these steps:1.

Verify Grid Profile

This is the most important. Double-check that the grid profile is correctly configured for a high-leg Delta system with the correct voltage.2.

Measure Voltages at the Inverter

Use a high-quality multimeter to measure the AC voltage at the inverter terminals (L1-N, L2-N, L3-N, and L1-L2, L2-L3, L3-L1). Verify that the high leg voltage is within the acceptable range for the inverter. Compare it to the voltage at the service entrance.3.

Check Wiring

Ensure that the AC wiring is correct, secure, and of the appropriate gauge. Loose connections or undersized wiring can cause voltage drops and imbalances.4.

Monitor Grid Voltage

Use a data logger or a multimeter with logging capabilities to monitor the grid voltage over a period of time (e.g., 24 hours). This will help you determine if the over-voltage events are consistent or intermittent. Are they happening at specific times of day?5.

Review Inverter Logs

Download the inverter's error logs (if possible) to see the frequency and duration of the over-voltage faults. This can provide clues about the cause.6.

Check for Other Loads

Are there any large or unusual loads on the same transformer that could be causing voltage fluctuations?7.

Check Impedance

I'd recommend doing a line impedance check as well. SolarEdge inverters in general have issues on longer wire runs.

In Summary: SolarEdge inverters are compatible with high-leg Delta systems, but proper configuration is essential. The most likely cause of your problem is an incorrect grid profile or grid type setting. Adjusting the voltage set point is a restricted function and should only be done as a last resort, with guidance from SolarEdge support.* Thorough troubleshooting is critical before making any changes to inverter settings.Start with the grid profile and wiring checks. Contact SolarEdge support for further assistance if needed. Good luck! Flag for review