Electrical faults range from the straightforward — a failed element in an electric hot-water service — to the fiendishly subtle, such as a high-resistance joint in a buried cable that only manifests under load on hot summer afternoons. VoltCity Surge's diagnostics team approaches every fault-finding job with a systematic methodology drawn from AS/NZS 3017 electrical installation testing procedures, combined with modern diagnostic instrumentation that eliminates guesswork and reduces time-on-site.
Thermal Imaging and Infrared Surveys
Thermal imaging is the single most powerful non-invasive electrical diagnostic tool available today. A calibrated radiometric infrared camera reveals elevated temperatures at loose terminations, overloaded conductors, failing neutral connections, and unbalanced three-phase loads that would otherwise remain invisible until they cause a fire or catastrophic failure. VoltCity Surge technicians carry FLIR radiometric cameras on all fault-finding calls and can provide standalone thermographic survey reports for switchboards, distribution boards, and cable plant suitable for submission to insurers or asset managers.
Circuit Tracing and Cable Location
In large commercial buildings, multi-tenancy residential developments, and industrial facilities, circuit documentation is frequently incomplete, inaccurate, or entirely absent. Our technicians use tonal cable tracers, capacitance-based locators, and signal-clamp injection methods to identify circuit routes, locate damaged cable sections in underground or concealed runs, and verify the accuracy of existing board schedules. Accurate circuit identification is a prerequisite for safe fault isolation and is always documented in a revised circuit schedule provided at job completion.
- Thermal imaging surveys of switchboards and cable plant
- Insulation resistance testing per AS/NZS 3017 to identify degraded cable
- Earth continuity verification with calibrated low-resistance ohmmeters
- RCD nuisance-tripping diagnosis with selective leakage current measurement
- Power-quality logging for voltage sags, harmonics, and transient overvoltages
- Underground cable fault location using time-domain reflectometry (TDR)
- Circuit schedule verification and as-built documentation updates
Intermittent Fault Diagnosis
Intermittent faults are the most frustrating category of electrical problem because they are frequently absent when the technician arrives. Our diagnostic approach for intermittent faults begins with a detailed interview with the building occupants — what loads are operating when the fault occurs, what time of day, what the ambient temperature is, and whether the fault is associated with specific equipment. From this we develop a hypothesis and deploy data-logging instruments that record voltage, current, and event timestamps over days or weeks, capturing the fault in the data log even when no technician is present. The log data is then analysed to pinpoint root cause before any remediation work begins.
Power Quality Monitoring and Analysis
Poor power quality — in the form of voltage harmonics from VSD drives and UPS systems, voltage unbalance in three-phase supplies, rapid voltage changes from large motor starts, or low power factor from inductive loads — causes a wide range of symptomatic problems including nuisance RCD tripping, overheating of neutral conductors, premature failure of capacitors and sensitive electronics, and elevated energy bills. VoltCity Surge deploys IEC 61000-4-30 Class A power-quality analysers that record all power-quality parameters simultaneously over a monitoring period of one to four weeks, producing an analysis report that identifies parameters outside AS 61000.3 limits and recommends corrective measures including filtering, re-phasing, or load scheduling.
Rapid On-Site Diagnosis and Same-Day Rectification
For a large proportion of electrical faults, diagnosis and rectification can be completed in a single attendance. Our technicians arrive with a fully stocked van including common cable sizes, circuit breakers, RCBOs, cable joints, conduit, and terminal blocks so that straightforward faults identified on diagnosis can be rectified on the spot. We follow every fault rectification with verification testing per AS/NZS 3017 to confirm the installation is compliant and the fault has been fully resolved, and we issue a written fault report and CCEW for any remediation work performed. Our 24/7 emergency response line means that fault-finding attendance outside business hours carries the same diagnostic rigour as a scheduled visit.
Frequently Asked
Why does my RCD keep tripping but I cannot find what is causing it?
Nuisance RCD operation is almost always caused by earth-leakage current that individually is below the tripping threshold on each circuit but collectively exceeds it when multiple circuits share a single RCD. It can also be caused by degraded cable insulation, water ingress into cable or fittings, or a fault in a specific appliance. We use a selective leakage current clamp to measure the leakage from each circuit individually under load, pinpointing the source without disconnecting every appliance.
Can you find a fault in an underground cable without digging?
In many cases, yes. For cable faults that result in a low-resistance path to earth or between conductors, we use time-domain reflectometry (TDR) to measure the distance to the fault point from the switchboard end of the cable. This typically narrows the fault location to within 0.5 metres, dramatically reducing the amount of excavation required. For open-circuit cable faults, we use a combination of capacitance measurement and tonal tracing techniques to locate the break.
What does a power quality report include?
Our power quality reports present logged data for voltage (per phase and line-to-line), current, power factor, total harmonic distortion (THD-U and THD-I), voltage unbalance, and recorded power-quality events (sags, swells, interruptions, and transients). Each parameter is assessed against AS 61000.3 limits, and any exceedances are annotated with likely causes and corrective recommendations. Reports are prepared in PDF format with embedded trend graphs and event tables suitable for presentation to your energy retailer or network operator.
Do you provide a written report after a fault-finding job?
Yes, always. Every fault-finding attendance concludes with a written fault report that describes the symptoms observed, the diagnostic tests performed and their results, the root cause identified, the remediation action taken or recommended, and the verification test results. Where remediation work is carried out, a Certificate of Compliance for Electrical Work is issued. These records are essential for insurance claims, asset management, and future maintenance planning.