Electrical equipment manufacturers typically recommend comprehensive preventive maintenance and testing occur at least every three years for electrical distribution equipment. The frequency may need to be adjusted (most likely, more often) for harsh environments, critical equipment, load conditions or duty requirements. To help ensure electrical reliability, less complex preventive maintenance tasks should be ongoing. Routine monitoring and inspections are needed to ensure the electrical equipment is kept clean, cool, dry and tight.
1) Keep it Clean: The accumulation of dirt in an electrical enclosure can result in electrical tracking, which can cause arcing, especially during high humidity conditions. Another issue is most electrical equipment relies on unobstructed air circulation to cool the equipment. Dirt and dust accumulations can restrict airflow and affect the equipment’s ability to remain cool. Enclosures and equipment rooms should be properly sealed to keep rodents and vermin out. Finally, traffic in/out of electrical room should be kept to a minimum to help keep out additional dirt and dust.
2) Keep it Cool: Heat build-up in electrical equipment can shorten its life span. Electrical equipment generates heat due to current flow. Normal room ventilation typically removes the heat. Ensure adequate ventilation is provided for electrical equipment and the ventilation equipment is properly maintained. Additional causes of excessive heat build-up include that could shorten the lifespan of: 1) Overloaded circuits or poor quality connections; and 2) Operating electrical equipment for extended periods of time at elevated temperatures.
3) Keep it Dry: Any moisture in or around electrical equipment is a safety hazard and should be corrected immediately. Moisture can also damage equipment – even if an electrical failure does not occur – leaving the equipment unreliable and unsafe. It should be closely examined and tested by a qualified electrician to determine if parts can be repaired or replaced.
4) Keep it Tight. Loose connections are a major cause of electrical failures. A proper electrical connection is both mechanically and electrically secure. Hot spots are a major source of electrical failures, including fires. Thermography (infrared scanning) may be employed to detect bad connections and hot spots. These inspections should only be performed by a certified thermographer.
Unplanned electrical outages are costly. They consume valuable production time, may cause equipment damage and, worst case, injuries to personnel. In addition to the manufacturer’s recommended preventive maintenance, routine inspections and periodic checks help mitigate the risk of unplanned downtime between planned shutdowns. ALL electrical work should be performed by qualified electrical personnel, as defined by NFPA 70E.
Additional resources for improving electrical reliability can be found here.