Solar PV Fault Finding Manchester

Solar PV systems are electrical installations, and like any electrical system, they can develop faults that require specialist equipment and expertise to locate. DC arc faults in concealed wiring, degraded MC4 connectors behind panels, failed bypass diodes within individual panels, and earth faults caused by moisture ingress are all common issues that cannot be identified by visual inspection alone. These faults reduce your generation, can damage other components, and in the case of DC arc faults, present a genuine fire risk.

Manchester Renewables provides technical solar PV fault finding across Greater Manchester using professional-grade diagnostic equipment. Our MCS-certified engineers use FLIR thermal imaging cameras, Seaward Solar PV IV curve tracers, insulation resistance testers and DC clamp meters to systematically trace faults through your system from the panel array down to the consumer unit. We diagnose faults that other companies cannot find because we have invested in the right equipment and training.

Whether you have been told your system has an earth fault, your inverter keeps shutting down, one string is producing significantly less than the others, or your RCD keeps tripping, we have the tools and experience to find the root cause and recommend the most cost-effective solution.

Solar PV Fault Finding Manchester — What's Included

Thermal Imaging Fault Detection

FLIR infrared thermal imaging of your entire panel array to identify hotspots caused by failed cells, bypass diode faults, high-resistance connections and internal short circuits. Thermal anomalies are photographed and documented with temperature differentials for your records.

IV Curve Tracing & String Analysis

IV curve tracing of each string to produce a characteristic curve that reveals panel degradation, cell cracking, diode failure and connection resistance. We overlay the curves against ideal performance data for your specific panel model to quantify the extent of any fault.

Insulation Resistance & Earth Fault Testing

Megger insulation resistance testing of all DC cables, connectors and panel strings to locate earth faults and insulation breakdown. Earth faults are one of the most common solar PV issues and can be caused by water ingress into junction boxes, rodent-damaged cables or deteriorated MC4 connectors.

DC Connection & Polarity Verification

Systematic testing of every MC4 connector, junction box and isolator in the DC circuit. We check for correct polarity, connection resistance, water ingress and heat damage. Poorly crimped or corroded MC4 connectors are a frequent cause of reduced output and arc fault risk.

Fault Report & Repair Quotation

A detailed fault report documenting every test performed, all findings with supporting images and data, and a clear repair quotation. We explain the fault in plain language so you understand what has gone wrong, why it matters, and what needs to be done to fix it.

UK Government Scheme

MCS Consumer Code: Safety and compliance protection

The MCS Consumer Code and the IET Code of Practice for Solar PV Systems require that all electrical faults in solar installations are diagnosed and repaired by qualified persons using appropriate test equipment. Using an MCS-certified installer for fault finding means all work meets the required safety standards and that your system remains compliant with building regulations, manufacturer warranties and DNO connection agreements.

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Why Solar PV Fault Finding Manchester Matters

DC arc faults caused by degraded connectors and wiring are a leading cause of solar panel fires — early detection is critical for safety
Earth faults can cause your system's RCD to trip repeatedly, cutting power to your entire property
A single failed bypass diode in one panel can reduce the output of an entire string by 30% or more
Moisture ingress into junction boxes and MC4 connectors accelerates corrosion, meaning faults worsen progressively if not addressed
Many faults are intermittent, appearing only under certain temperature or load conditions, making them difficult to diagnose without specialist equipment

Cost Guidance

Solar PV fault finding in Manchester typically costs between £200 and £400 for a domestic system, depending on the complexity of the fault and the number of strings and panels involved. This covers the diagnostic visit with all necessary testing and a detailed written report. If the fault can be repaired on the same visit — such as replacing a failed MC4 connector or bypass diode — we include the repair time and charge only for parts. Complex faults requiring panel removal, cable replacement or roof work are quoted separately after diagnosis.

More Solar System Service Services

Solar Inverter Repair Solar Panel Health Check Solar Panel Performance Monitoring

Solar PV Fault Finding Manchester — Common Questions

My inverter shows an earth fault error. What does this mean?

An earth fault means that current is leaking from the DC circuit to earth somewhere in your system. This is commonly caused by water ingress into a panel junction box or MC4 connector, damaged cable insulation from rubbing against roof tiles or rodent damage, or deterioration of the insulation within a panel itself. Earth faults are a safety issue and should be investigated promptly. We use megger testing to locate the exact point of insulation breakdown.

One string is producing much less than the others. What could cause this?

The most common causes of single-string underperformance are a failed bypass diode in one panel (which affects the whole string), a high-resistance MC4 connection, partial shading on one or more panels in the string, or a damaged cable. We test each string individually with IV curve tracing and thermal imaging to isolate the fault to a specific panel or connection point.

Can you find intermittent faults that only appear sometimes?

Yes, though intermittent faults can be more time-consuming to diagnose. Many solar faults are temperature-dependent — a connection that works fine when cold may develop high resistance when panels heat up in direct sun. We use thermal imaging during peak generation to catch these thermal-dependent faults, and we can install temporary monitoring equipment to log intermittent issues over several days if needed.

My RCD keeps tripping and I think it is the solar panels. Can you confirm this?

Yes. We can systematically isolate each circuit to determine whether the solar PV system is causing the RCD trip. If it is, we then trace the fault through the DC and AC circuits to find the source. Common causes include earth faults in the DC wiring, a failing inverter with leakage current above acceptable levels, or incorrectly selected RCD protection that is too sensitive for the type of inverter installed.