Victron MultiPlus-II High Cell Voltage Alarm –... | solardiagnostics.org

Technical Background:

The high cell voltage alarm is triggered when the voltage from the solar array exceeds the inverter's maximum input voltage threshold. This can occur during peak solar irradiance or due to temperature variations affecting the photovoltaic (PV) modules. The inverter employs a Maximum Power Point Tracking (MPPT) algorithm to optimize energy harvest, but when voltage exceeds safe limits, it will shut down to prevent damage. The inverter continuously monitors insulation resistance (RISO) and ground faults, which can also contribute to triggering alarms if voltage anomalies are detected.

Symptoms:

The Victron MultiPlus-II inverter displays a high cell voltage alarm, typically indicated by a red LED flashing pattern or an alert on the Venus OS monitoring app. Users may also notice a significant drop in power production, with the inverter ceasing to feed energy into the utility grid.

Possible Causes:

Overvoltage from the solar array due to high irradiance or temperature conditions.
Faulty or degraded solar modules causing uneven voltage distribution.
Incorrect string configuration leading to voltage imbalances.
Poor connections or corrosion at junction boxes affecting voltage readings.
Malfunctioning MPPT (Maximum Power Point Tracking) algorithm within the inverter.
Inadequate grounding or grounding faults affecting voltage stability.

Solution:

1

Disconnect the inverter from the utility grid and turn off the DC disconnect switches to ensure safety.
2

Use a multimeter to measure the open-circuit voltage (Voc) of each string in the array to identify any strings exceeding the maximum input voltage rating of the inverter.
3

Inspect all connections at the junction box and combiner box for corrosion or loose connections, tightening or replacing as necessary.
4

Check the configuration of the strings to ensure they are within the specified limits for the inverter; adjust as needed.
5

If high voltage persists, inspect the solar modules for any signs of damage or degradation, replacing any faulty modules.
6

Reconnect the system and monitor the inverter's performance through the monitoring app for any recurrence of the alarm.
7

Consider consulting the Victron MultiPlus-II manual for firmware updates or specific settings adjustments related to high voltage conditions.

Safety Warning:

Always consult a licensed electrician or certified solar installer when performing maintenance or troubleshooting on solar inverter systems to ensure compliance with safety standards and local electrical codes.

Prevention:

To prevent future occurrences of high cell voltage alarms, ensure regular maintenance of the solar array, including cleaning the modules and checking for shading issues. Conduct periodic inspections of all electrical connections and verify that the string configurations remain within the inverter's specifications. Additionally, consider utilizing voltage regulation devices if high voltage conditions are common in your area.

Frequently Asked Questions

•What causes the High Cell Voltage Alarm?

The High Cell Voltage Alarm can be triggered by overcharging or faulty battery cells. It's important to check the battery voltage levels and ensure they are within the recommended range.

•How can I reset the alarm after fixing it?

To reset the alarm, you can power cycle the inverter or use the Venus OS interface to clear the alarm notification. Ensure the underlying issue is resolved before resetting.

Victron MultiPlus-II High Cell Voltage Alarm – Troubleshooting & Technical Fix Guide

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Frequently Asked Questions

•What causes the High Cell Voltage Alarm?

•How can I reset the alarm after fixing it?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention: