SolaX Grid Voltage Fault (IE03 & IE08): UK Settings and Fix Guide

Key Takeaways

• SolaX error code IE 03 indicates an instantaneous grid voltage overrun, while code IE 08 signals that the 10-minute rolling average voltage has breached statutory thresholds.
• SolaX systems are designed for automatic recovery: when distribution network voltages stabilize within allowable limits, the inverter automatically recommences power conversion.
• Never adjust safety protection parameters without utility authorization; changing regional grid standards requires certified installer permissions to prevent grid code compliance violations.
• Persistent nuisance tripping on sunny days usually indicates local distribution line impedance and cable volt-rise rather than a defective inverter.

Understanding SolaX grid voltage alarms (IE03 and IE08)

SolaX residential and commercial inverters continuously sample the alternating current waveform received from the public electricity network. When incoming voltage exceeds upper or lower limits defined by regional network codes, the inverter initiates an immediate safety shutdown:

1. IE 03 (Grid Volt Fault): Denotes a Power grid voltage overrun. The instantaneous AC voltage has crossed the programmed upper trip threshold. Under manufacturer operational logic: wait a moment, if the utility returns to normal, the system will reconnect. However, installers must check if the grid voltage is within normal range if the event repeats.
2. IE 08 (AC10mins Volt): Represents grid voltage out of range in the last 10 minutes. Under British standards, solar inverters must track the 10-minute rolling average voltage to ensure distribution networks do not suffer chronic overvoltage. The system will return to normal if the grid returns to normal.

In Great Britain, public low-voltage supplies operate within strict statutory distribution limits. Detailed statutory grid parameters are documented in our micro-generator grid connection guide and Type A connection guide.

UK safety code configuration on SolaX inverters

A frequent cause of spurious IE 03 and IE 08 trips on newly commissioned systems is an unconfigured or incorrect regional safety standard. Official SolaX engineering manuals emphasize: the inverter cannot be connected to the grid before the safety code is correctly set.

To configure or verify the correct UK grid standard on the LCD screen:

1. Access Advanced Menu: Navigate through the interface via Setting path: Menu>Setting>Advance Setting.
2. Enter Installer Credentials: Input the installer passcode. The default password is "0 0 0 0". You can reset the password here if required.
3. Select Regional Grid Code: Enter the safety code submenu referenced as Table 10-3 Safety code.

• In England, Scotland, and Wales, select G99 United Kingdom.
• In Northern Ireland, select G100 NI Northern Ireland.

4. Confirm Grid Parameters: Verify the internal protection thresholds listed under the menu:

• ====Grid Parameters====
• >Overvoltage_L1
• Undervoltage_L1
• OverFreq_L1

Selecting the correct standard ensures that the inverter uses approved British trip thresholds rather than tighter European default profiles. Wiring regulations governing this setup follow our UK solar electrical installation guide.

Volt-rise and AC line impedance troubleshooting

When SolaX inverters trip with IE 03 or IE 08 exclusively during periods of high solar irradiance (between 11:00 AM and 2:00 PM), the root cause is frequently cable volt-rise.

To push generated electricity backwards into the home consumer unit and onward into the distribution grid, the inverter must generate an output voltage slightly higher than the prevailing grid voltage. If the AC cable run between the inverter and consumer unit is excessively long, undersized (such as 2.5 mm² instead of 4.0 mm² or 6.0 mm²), or contains loose isolator screw terminals, the electrical resistance of the circuit forces the terminal voltage to rise significantly.

Follow these diagnostic steps:

1. Firmware and Standard Verification: 1.Update to the latest firmware. 2. Check the safety code settings and the grid voltage.
2. Measure Voltage at AC Port: Step 1: Use a multimeter to measure the phase voltage and line voltage at the AC port. Ensure grid voltage is normal.
3. Compare Standby vs Export Voltage: Measure AC voltage with the inverter in standby (generating 0W), then monitor the voltage rise as solar export climbs to peak output. If the voltage rise across the AC circuit is excessive, the circuit impedance is too high and cabling must be upgraded.

Grid voltage triage matrix

Electrical safety during grid voltage testing

Measuring distribution grid characteristics requires adherence to established safety practices:

• Personal Protective Equipment: Always wear personal protective equipment (PPE) including safety glasses and insulated footwear when testing energized AC switchgear.
• Capacitor Discharge Time: After the inverter is powered off, there may still be residual electricity and heat which may cause electric shocks and body burns. Please wear personal protective equipment (PPE) and start maintaining the inverter at least five minutes after power off.
• Authorized Alterations Only: Never attempt to bypass overvoltage limits or alter statutory G99 trip settings without written formal consent from the regional UK Distribution Network Operator.

Escalating to SolaX technical service

If firmware updates, safety code verification, and physical voltage checks confirm that incoming grid voltage is within statutory limits but the inverter persists in reporting IE 03: 3.If the problem remains, Please contact the SolaX technical support team. Provide photographs of the serial number, measured AC port voltage, and the internal grid voltage reading from the On-grid diagnostic screen.