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Generac•PWRcell

Analysis by Marcus & Team

Generac PWRcell: Clicking Noise at Sunset

Troubleshoot a Generac PWRcell hybrid inverter clicking at sunset. Diagnose the issue and explore solutions for your residential energy storage system.

Frequently Asked Questions

•What is the typical lifespan of the PWRcell battery?

The PWRcell battery lifespan is typically around 10 years, but it can vary depending on usage and environmental conditions. Monitor the SOH value.

•How do I check the firmware version of my PWRcell inverter?

You can check the firmware version through the Generac PWRcell monitoring app or web interface. The specific steps may vary depending on the app version.

•What are the voltage limits of the PWRcell battery?

The voltage limits vary based on the configuration. Refer to the PWRcell installation manual for the exact voltage range and limitations for charging and discharging. Typically it's 48V nominal but specific parameters depend on module config.

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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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Technical Overview:

The Generac PWRcell system uses a hybrid inverter to manage power flow between solar panels, battery storage, and the electrical grid. The inverter incorporates MPPT algorithms to optimize solar energy harvesting. DC power from the solar array is converted to AC power for household consumption or grid export. Surplus energy charges the battery. The clicking is likely due to relay operation as the inverter switches between grid-tied, battery backup, and standby modes when the PV array output diminishes at sunset.

Important Warnings:

High DC voltage is present in the solar array and within the inverter. Only qualified electricians should perform diagnostics and repairs. Follow NEC Article 690 guidelines for safe PV system system and maintenance. Ensure the DC disconnect switch is in the OFF position and verify no voltage is present before performing any work on the DC side of the system. Arc flash hazard exists. Wear appropriate personal protective equipment (PPE).

Recommended Action:

1

*Verify Solar Array Voltage and Current:** Using a multimeter, measure the open-circuit voltage (Voc) and short-circuit current (Isc) of each solar string during daylight hours. Ensure readings are within the manufacturer's specifications. Note readings at different times of day to capture the voltage drop off as sunset approaches.
2

*Inspect DC Disconnect Switch:** Ensure the DC disconnect switch is functioning correctly and providing a stable connection. Check for corrosion or loose wiring.
3

*Monitor Inverter Operating Mode:** Use the Generac PWRcell monitoring app or web interface to observe the inverter's operating mode (e.g., grid-tied, battery backup, standby) when the clicking occurs. Note the DC bus voltage and AC grid voltage at the time of clicking.
4

*Check Battery State of Charge (SOC) and State of Health (SOH):** Review battery performance metrics via the monitoring system. Low SOH or SOC imbalances may cause frequent switching.
5

*Review Inverter Firmware Version:** Check the firmware version and update to the latest version if available, following the manufacturer's instructions. Incorrect firmware can cause relay chatter.
6

*Analyze Grid Voltage:** Using a power quality analyzer, monitor the grid voltage for fluctuations or disturbances that may be triggering the inverter. NEC 690.11 requires arc fault protection on PV systems; unstable grid voltage can mimic arc faults.
7

*Consult Generac Technical Support:** Contact Generac technical support with the collected data for further diagnosis and troubleshooting.

Common Causes:

Relay chatter due to low DC input voltage from solar panels as irradiance decreases.
Contactor engagement/disengagement within the battery management system (BMS) controlling charge/discharge cycles.
Firmware issue causing frequent switching between operating modes.
Grid instability or voltage fluctuations triggering inverter response.
DC disconnect switch malfunction causing intermittent interruption of PV power.
Internal component failure within the inverter’s power electronics.

Prevention:

Schedule annual system inspections by a qualified electrician to check wiring connections and component health.
Regularly monitor the system's performance through the Generac PWRcell app or web interface.
Ensure the inverter firmware is up to date.
Perform a battery capacity test annually to assess battery health.
Check for any shading on the solar panels, especially during sunset hours, as this can cause rapid voltage fluctuations.