Warning What does this mean?

Your system is down or running degraded, but this is not an immediate safety danger. Work through the safe steps below.

Solis Inverter G-IMP Error: Meaning, Causes & Safe Fix

Your Solis inverter measured high impedance (electrical resistance) on the grid connection and stopped feeding power.

What should I do first?

Two quick questions — we'll point you to the right starting point.

Is this code still showing on your inverter's display?

What this code means

G-IMP means 'high grid impedance.' The inverter checks the impedance of the grid connection; if it is too high — a weak grid or a poor connection — safe feeding isn't possible, so the inverter raises this alarm and stops exporting power.

What is this downtime costing you?

Rough estimate while your system isn't producing. Adjust the numbers to match your setup.

System size (kW) Peak sun hours / day Electricity rate ($/kWh)

–per day

–per week

–per 30 days

≈ – kWh of lost production per day.

Estimate only — assumes ~80% real-world output vs. nameplate. Actual losses depend on weather, shading, panel direction, and your tariff.

Common causes

Weak rural or long grid feeders with naturally high impedance
Undersized or over-long AC cable between inverter and grid connection
Loose AC terminal connection

Safe steps to try

Work top to bottom, ticking off each step as you complete it. 0 of 5 done.

Note the code and the time it appeared
Perform one documented restart (AC OFF, DC OFF, 5-minute wait, DC ON, AC ON)
Notice whether the fault appears at high-export times like midday — that clue helps your installer
Do not touch any AC terminals or breakers beyond a single reset
If it persists, contact your installer

Is your inverter still under warranty?

Before paying for a repair, check — your installer may fix this free.

Brand Year installed

Based on typical standard warranty terms — always confirm with your warranty card or installer paperwork, as terms vary by model, region, and purchase date.

When to call an electrician

Call your installer — high impedance needs professional diagnosis of the AC cabling and grid connection. This is not homeowner-fixable, and AC terminals must never be touched by anyone unqualified.

Frequently asked questions

Does G-IMP mean my inverter is broken?

It's about the grid connection's electrical characteristics, not a broken inverter. The inverter is refusing to feed into a grid it considers unsafe.

Will restarting fix it?

A restart is worth one try for transient events, but persistent G-IMP is a wiring or grid issue that needs your installer.

Is high grid impedance my utility's fault?

Often it's the local network — long rural feeders have naturally higher impedance. But undersized AC cable on your side can cause it too, which is why your installer needs to check both.

Need a professional?

This fault may need professional diagnosis. Contact a qualified solar electrician in your area.

Sources: meaning and troubleshooting verified against the manufacturer's documentation — Solis S5-GR3P(3-13)K Three Phase Inverter User Manual (Ginlong Solis), Table 9.1