Note the exact fault
Save an app screenshot or photograph the display only if it is safely accessible. Include the inverter brand and model if you already know them.
Solar Inverter Isolation Faults | Redlands & Brisbane
Solar fault finding · Redlands & Brisbane Bayside
Inverter showing an isolation fault?
An isolation warning can mean the electrical insulation between your solar panels or DC wiring and earth is too low. Your inverter may stop generating or refuse to start until the condition clears.
It does not automatically mean you need a new inverter. We investigate the system, explain what we find and discuss the repair options with you.
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What should you do when the warning appears?
You do not need to diagnose the fault before contacting us. These details help us understand what is happening without you touching the electrical equipment.
Tell us when it happens
Does it appear after rain, early in the morning or throughout the day? Has there been a storm, roof work or a change in generation?
Leave testing to an electrician
Contact a licensed electrician experienced in solar. Do not open covers or isolator enclosures, unplug solar cables, climb onto the roof or keep resetting the inverter to clear the message.
Smoke, sparking, burning smells or damaged equipment?
Keep people away and seek urgent help. For fire or immediate danger, call 000. Do not touch wet, burnt or storm-damaged solar equipment, and do not approach it to operate switches. Solar panels can still produce dangerous voltage in daylight, even when the inverter or mains supply is off.
A warning disappearing later is not proof that the underlying cause has been repaired.
Understanding the warning
Isolation fault, insulation fault or “Riso Low”?
These messages can relate to the inverter detecting inadequate insulation resistance in the solar DC circuit. Insulation normally keeps electricity within its intended path. A low reading needs investigation to determine the cause.
The exact wording and response depend on the inverter model. Some warnings stop generation; others may appear while the system is still operating. Record the message rather than trying to interpret a generic fault-code list.
Is an isolation fault the same as a faulty isolator?
No. An isolator is a switch used to disconnect part of the system. An isolation warning concerns electrical insulation. An isolator can be involved, but the warning alone does not identify that component as the cause.
Why can it happen after rain or first thing in the morning?
Moisture can make an existing insulation problem more noticeable. The warning may clear as the system dries, then return with rain or dew. Intermittent faults still need a proper check.
Possible causes we investigate
- Moisture affecting DC connectors, cabling or isolator enclosures.
- Damaged or deteriorated cable insulation.
- Damage or insulation problems within solar panels.
- Connection or installation issues affecting the DC circuit.
The inverter, system design and model-specific behaviour may also need assessment. A fault message is a starting point, not a complete diagnosis.
Useful information for your enquiry
- Your suburb and best contact number.
- The warning text or code and inverter make/model.
- When it started and whether it comes and goes.
- Any recent storm damage, roof work or changes to the system.
- A safely taken display photo or app screenshot, if available.
Do not climb up or open equipment to collect these details.
Diagnosis before replacement
How Solair Electrical can help
We provide solar fault finding and repairs for homeowners in Redlands and Brisbane Bayside. The aim is to identify the problem and give you a practical next step, rather than assume the inverter is faulty.
Find the affected part
We assess the fault history and inspect relevant panels, DC cabling, connections and equipment. Electrical testing, including insulation resistance testing where appropriate, helps locate the issue.
Know what needs attention
We explain the findings and whether repair, component replacement or further investigation is needed. Intermittent faults can depend on weather and may need additional checks.
Check the work properly
For agreed repair work, we address the identified fault and complete the relevant testing. If equipment is unsafe or cannot be repaired reliably, we explain why and discuss the next step.
Tell us what your inverter is showing
Send the warning and your suburb, or give us a call. We can discuss the next step and availability for an inspection.
Local people, clear advice
Solar support from a local electrical team
Solair Electrical is a family-owned electrical business based in Thornlands. We help homeowners across Cleveland, Capalaba, Alexandra Hills, Birkdale, Wellington Point, Ormiston, Victoria Point, Redland Bay and nearby Brisbane Bayside suburbs.
Our work covers solar inspections, fault finding and repairs. We explain the condition of your system and the options available without treating every warning as a reason to replace everything.
Electrical Contractor Licence: 1503341
For other inverter messages, low output or general system issues, see our solar repairs service.
Common homeowner questions
Before you book
Does this mean my inverter needs replacing?
Not necessarily. The warning may relate to panels, DC wiring, connections or other equipment. Testing is needed before deciding whether the inverter or another component requires repair or replacement.
Can I ignore it if the system starts working again?
A recurring warning should be investigated, even if generation returns. Moisture-related faults can disappear as equipment dries without the underlying issue being fixed. Keep a record of when the warning appears and contact us.
Should I restart or switch off the system myself?
There is no single safe reset or shutdown sequence for every installation. Do not repeatedly reset an inverter to clear a recurring warning. Contact your installer or a licensed solar electrician for advice specific to your system. If equipment is wet, damaged, sparking or affected by a storm, stay away and do not try to operate it.
How much does fault finding or repair cost?
It depends on the system, access and testing required, and whether parts need replacing. Tell us your suburb, inverter model and warning so we can discuss the inspection scope and pricing. Repair costs depend on what the investigation finds.
Can you provide a report for an insurance claim?
We offer solar insurance inspections and reports. Tell us if you need a written report when enquiring so the scope is clear. Whether a claim is covered is a decision for your insurer under your policy.
How often should my solar system be inspected?
Follow the manufacturer's maintenance guidance and advice for your system's age, condition and location. Arrange an inspection promptly if a fault appears or you suspect damage. For a broader condition check, see our solar inspection service.
Further safety information
For independent guidance, read the Queensland Electrical Safety Office's solar PV advice and its storm and damaged-equipment guidance. SMA's technical note on insulation errors explains why intermittent warnings still need professional investigation.
This page is general homeowner information, not a diagnosis of your system or instructions for electrical work.
Need help with an isolation fault?
Speak with Solair Electrical about solar fault finding in Redlands and Brisbane Bayside.