A loose lug on a 400-amp main switch can sit at 80 °C for months before it fails — long enough to oxidise the termination, scorch the insulation, and eventually let go in the middle of a Tuesday lunch service. The only way to catch it before then is an infrared camera under load. Thermographic inspection is the predictive-maintenance discipline that finds those slow-burning faults — loose terminations, phase imbalance, oxidised joints, stressed contactors, failing capacitors, hot string connectors on rooftop solar — before they become an outage, a fire, or an insurance claim. Millar Electrics runs annual programmes for commercial property owners, owners corporations, and facility managers across Melbourne's eastern suburbs, with severity-classified reports the asset record can stand on.
What we scan
The bread-and-butter scope is every loaded electrical asset on the site: the main switchboard from incoming consumer mains to outgoing sub-mains, distribution boards on each floor or zone, motor control centres for plant rooms and refrigeration, and the cable terminations and busbar joints inside each. On rooftop solar we walk the array with the strings under irradiance — checking MC4 connectors, junction-box patterns for bypass-diode failure, DC isolators, and inverter terminals. EV chargers, capacitor banks, and standby-generator switchgear get added to the scope when they're on site. The scan happens with the gear energised under representative load — the only load condition where faults actually show up.
What you get back
A written report, by board and by finding. Every finding gets a paired IR and visible image, the max measured temperature, the reference temperature (similar component or ambient), the ΔT on both axes, the camera settings used (emissivity, reflected temperature, distance), the operating load at time of measurement, a severity classification against the NETA MTS or NFPA 70B scheme, a probable cause, a recommended corrective action with time-frame, and a recommended retest interval. A summary front-sheet groups the findings by severity so the facility manager can prioritise; an asset-records appendix retains the raw thermal files for audit cross-reference. Reports are PDF and digital — both formats kept for the seven-year electrical-record retention period.
When to schedule it
Annual is the right cadence for most commercial sites — quoted in the same way an annual safety inspection or fire-services service would be. We slot the scan into a window when the equipment is operating at normal load: a regular trading day for retail or hospitality, mid-morning for offices, mid-shift for warehouses. Pre-purchase due-diligence inspections happen on a one-off basis and feed into the building condition report. Post-fault scans get scheduled within a week of the event so the thermal signature of the recovery is captured. After any board upgrade or sub-main replacement we re-scan at 30 days under similar load to confirm the new terminations have settled correctly.
Compliance and credentials
Inspections are performed by an A-grade Victorian electrician — necessary because opening an energised switchboard under load is electrical work under the Electricity Safety Act 1998, regardless of any separate thermography qualification the operator might hold. Work method follows AS/NZS 4836 (safe working on or near low-voltage installations and equipment), with a documented risk assessment for each scope. Cameras carry current ISO 17025 calibration certificates. Severity classification follows NETA MTS or NFPA 70B; if your insurer specifies a different scheme, we'll use theirs and reference it on the report cover. Solar PV scans align with IEC 62446-3 (outdoor IR thermography of PV plants). All findings remain Millar Electrics' record for the audit period whether you assign the corrective work to us or to another contractor.