SolarEdge Isolation Fault — What It Means & What to Do

What Does This Error Mean?

An isolation fault on a SolarEdge inverter means the electrical resistance between the DC solar circuit and ground has dropped below the safe minimum. This indicates damaged, degraded, or wet wiring creating a partial ground fault. The inverter shuts down to prevent a safety hazard. This requires inspection by a licensed solar electrician.

Affected Models

SolarEdge SE2200H
SolarEdge SE3000H
SolarEdge SE5000H
SolarEdge SE7000H
SolarEdge SE10000H
SolarEdge StorEdge (all models)
SolarEdge Three-Phase Inverters

Common Causes

Wet wiring — rain or condensation on panel connectors or in junction boxes temporarily reducing isolation resistance
Cable insulation degraded from UV exposure, heat, or animal damage
MC4 connector improperly assembled or cracked — allowing moisture into the connection
Soiling on panel surfaces combined with moisture creating a conductive path
Old panels with degraded backsheet allowing current to leak to the frame

How to Fix It

Note whether the fault appeared during or after rain.

Isolation faults that appear when wet and clear when dry are common indicators of a connector or junction box seal failure. Note the weather conditions when the fault appeared — this is important information for the electrician.
Do not restart the inverter.

Restarting re-energises a compromised circuit. The inverter's shutdown is protecting against a potential arc or fire in the wiring.
Contact your solar installer or a licensed electrician.

If the fault clears after dry weather and then reappears with rain, mention the pattern to the technician — this significantly narrows the search for the fault location.

When to Call a Professional

Isolation faults require inspection by a licensed solar electrician. Do not attempt to reset or restart the inverter — contact your solar installer.

Frequently Asked Questions

Can an isolation fault clear on its own?

Sometimes — if the cause was wet connectors, the fault may clear after the system dries out. However, even if it clears, the underlying seal failure that allowed water in will cause the fault to return with the next rain. Arrange an inspection regardless of whether it cleared.

Is an isolation fault the same as a ground fault (Error 153)?

They are related but not identical. An isolation fault means the insulation resistance has dropped — a warning level. Error 153 (ground fault) means a definite ground fault path has been detected. Both require the same response: do not restart, call an electrician.