Electrical maintenance services perform electrical system testing, efficiency analysis, reliability determination, safety checks, and scheduled shutdowns of electrical assets such as motors, transformers, power supplies, and co-generation systems. The upgrades and repairs that electrical maintenance services perform help to prevent costly downtime at electric utilities, power plants, factories, and other manufacturing and power generation facilities. Often, electrical maintenance services adhere to standards such as the National Electrical Code (NEC), or follow codes and standards from the International Electrical Testing Association (NETA) and the National Fire Protection Association (NFPA).
Electrical maintenance services differ in terms of capabilities. Some companies provide or perform power equipment start-ups, commissioning, acceptance testing, maintenance testing, power quality surveys, electrical asset replacement, system retrofits, and device renewals. Others specialize in electrical system overhauls and upgrades, plant life cycle support (PLCS), life extension, reliability analysis, predictive maintenance (PdM), and preventive maintenance (PM). Electrical engineering services, electrical inspection services, and electrical maintenance services that specialize in troubleshooting are also available.
The electrical testing activities that electrical maintenance services perform range from low and medium voltage testing to high voltage testing. Specific inspection types and measured variables include infrared surveys, corona analysis, arc flash testing, dielectric absorption, shield continuity, resistance testing, doble testing (doble power factor testing / dissipation factor testing), insulation power factor testing, and polarization index testing. Test types may also include dissolved gas in oil analysis, dielectric fluid testing, electrical forensic analysis, fault location, load testing, circuit testing, and oil ATM screen testing for transformers. Measured variables include polarization index or PI index, power factor and power factor correction (PFC), power quality, transient power, transformer leaking, turns ratio, and voltage drop. Winding testing is also available.
Electrical maintenance services test, repair, and upgrade many types of electrical assets. Examples include automatic transfer switches, back-up power systems, batteries and battery systems, electrical cables, capacitors, capital equipment such as rotating machinery, circuit breakers, circuit interrupters, circuit re-closers, circuit switchers, cogeneration equipment, and cogeneration systems. Companies that test and measure corona damage, dielectric absorption, and dielectric fluid can also maintain digital relays, electrical contacts, electrical distribution systems, electrical power equipment, electrical power generators, electromechanical relays, and emergency electrical systems.
Electrical maintenance services may test or replace fuses, generators, ground grids, ground fault systems, high voltage substations, electrical insulation, insulating oil, load break switches, medium voltage cables, motors, motor drives, oil breakers, panel boards, power lines, power meters, and power supplies. In addition to power equipment, power factor machinery, and power generation systems, electrical maintenance services may test or replace protective relays, SF6 breakers, switchgear, uninterruptible power systems (UPS), vacuum circuit breakers, variable frequency drives (VFD), voltage regulators, and watt meters.