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SolarEdge•Optimizer

Analysis by Marcus & Team

SolarEdge Optimizer Wake-up Failure

Troubleshoot SolarEdge Optimizer wake-up failures. Learn causes, solutions, prevention, & safety. Prioritize NEC rapid shutdown compliance.

Frequently Asked Questions

•How does the inverter initiate the 'wake-up' signal to the optimizers?

The inverter sends a specific voltage level or coded communication signal through the DC string wiring to signal the optimizers to begin operation. The specific protocol is proprietary to SolarEdge, but generally involves a change in voltage or current that the optimizers are programmed to recognize.

•What are the acceptable voltage drop limits along the DC string wiring?

The NEC recommends limiting voltage drop to 3% in the feeder (inverter to first module) and 5% in the branch circuit (module string) for a total of 5%. However, minimizing voltage drop as much as possible is always beneficial for system efficiency. Consult SolarEdge documentation for specific recommendations based on string length and wire gauge.

•What type of PPE is required when working on a SolarEdge PV system?

At a minimum, insulated gloves rated for the maximum DC voltage of the system, safety glasses, and appropriate arc-rated clothing are required. Follow all OSHA and NEC guidelines for working on energized electrical equipment. De-energizing the system is the preferred method whenever possible.

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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.

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What to Look For:

Optimizer fails to initiate power production in the early morning (around 7 AM). Inverter reports communication errors or missing power from affected string(s). Monitoring system indicates zero output from specific modules despite sufficient irradiance.

Technical Overview:

SolarEdge optimizers are DC-DC converters that maximize the power output of each PV module and communicate performance data to the inverter. They rely on a wake-up signal from the inverter to begin operation in the morning. This signal typically involves a specific voltage level or communication protocol transmitted along the DC string wiring. Failure to receive or properly interpret this signal prevents the optimizer from initiating DC-DC conversion and reporting power to the inverter. The rapid shutdown system must ensure voltage reduction to safe levels (<30V within 30 seconds) upon AC disconnection, per NEC 2017/2020 requirements.

Pro Tip:

Use the SolarEdge SetApp to diagnose optimizer issues. The SetApp can provide real-time data from each optimizer, including voltage, current, and temperature. This can help pinpoint the source of the wake-up failure. Look for unusual temperature readings or voltage discrepancies compared to other optimizers on the same string.

Critical Safety Precautions:

DC high voltage is present in PV systems. Always disconnect the DC disconnect switch before working on any PV system components. Wear appropriate personal protective equipment (PPE), including insulated gloves and safety glasses. Adhere to all NEC and local electrical codes. A qualified electrician must perform all electrical work. Arc flash hazard exists; de-energize circuits before inspection.

Step-by-Step Fix:

1

Verify inverter operation: Use a multimeter to check the DC voltage output of the inverter at the string connection points during the expected wake-up time (around 7 AM). Confirm the presence of the wake-up signal according to SolarEdge specifications.
2

Inspect DC string wiring: Visually inspect all DC string wiring connections for corrosion, loose connections, or damage. Use a clamp meter to measure the current in each string and verify it's within the expected range. Measure voltage drop along the string with a multimeter; excessive drop indicates wiring issues.
3

Test individual optimizer functionality: Disconnect the affected optimizer and use a SolarEdge commissioning tool or multimeter to test its functionality. Check for the presence of voltage and current when exposed to sunlight. Follow SolarEdge's specific procedures for isolating and testing optimizers.
4

Update firmware: Ensure both the inverter and optimizers have the latest compatible firmware versions. Use the SolarEdge monitoring portal to initiate firmware updates.
5

Check for grounding issues: Verify proper grounding of the PV system according to NEC 250 requirements. Use a ground resistance tester to measure the resistance between the grounding electrode and the equipment grounding conductor.
6

Consult SolarEdge support: If the problem persists, contact SolarEdge technical support for further assistance. Provide detailed information about the system configuration, fault codes, and troubleshooting steps taken.
7

Ensure rapid shutdown compliance by verifying voltage levels drop below 30V within 30 seconds of AC disconnection, as per NEC 2017/2020 Article 690.

Why This Happens:

Maintenance Tips:

Perform regular visual inspections of all wiring connections.
Monitor system performance through the SolarEdge monitoring portal.
Schedule periodic firmware updates for the inverter and optimizers.
Conduct thermal scans (using an IR thermometer) of the optimizers and wiring connections to identify potential hotspots.
Annually test string voltages and compare to baseline measurements.