Common faults we diagnose weekly
Nuisance-tripping RCDs (usually accumulated small earth-leakage from multiple appliances stacking up over one RCD, or a specific circuit with insulation degradation), dead ring mains (loose terminations at faceplates, thermal damage from historic overload), flickering lights (dimmer / LED incompatibility, loose neutral, or supply-side issues), warm sockets (loose terminals, undersized cabling, chronic overload), and consumer units with a scorched terminal (loose termination running hot for months).
How we actually diagnose
Every fault find follows the same discipline: isolate, visually inspect, then use calibrated instruments. Insulation resistance (megger) testing at 500V DC finds cable and appliance-side insulation faults. Earth fault loop impedance testing verifies protective devices will disconnect within the required time. RCD ramp and trip-time testing verifies protection is working to spec. Thermal imaging (used on request for commercial distribution boards) finds loose terminations before they fail.
Planned maintenance for commercial premises
For commercial and light industrial clients we offer planned inspection cycles, typically quarterly emergency-lighting function testing, annual full-duration testing, PAT testing on a schedule that matches your equipment risk, and periodic thermal imaging of distribution boards on request. Planned cycles are always cheaper than reactive-only maintenance, and they generate the paperwork your insurer wants to see.
Residential vs commercial, where it differs
Domestic fault finding is usually a single isolated fault, one tripping circuit, one dead socket. Commercial fault finding often involves distribution and sub-mains, higher continuous loads, and much lower tolerance for downtime. Both use the same core discipline; commercial jobs are just scheduled differently and documented more heavily.