With increasing dependence on computers and automated processes, most modern facilities cannot afford downtime. And, as technologies, processes and user demands evolve over time, an electrical system must be able to support these changes. For companies with aging switchgear and budget constraints on capital improvement projects, there’s good news! Following are ten life extension tips to enhance electrical reliability.
1. Perform Infrared Inspections
Although not a substitute for a maintenance program, thermal imaging (infrared) is a valuable tool that can be done while the equipment is energized. If done safely and properly, an infrared inspection can identify loose bus connections before they result in a full or partial equipment outage. Maintenance can be scheduled to correct the identified issue. Having infrared viewing windows installed allows infrared inspections to be done quickly and safely.
2. Exercise Circuit Breakers on an Annual Basis
A simple but very valuable practice is to manually operate circuit breakers once a year. This keeps the contacts clean and helps operating mechanisms move freely.
3. Don’t Neglect Recommended Maintenance
Switchgear should be cleaned, inspected, tightened, lubricated, and exercised on a regular basis. The frequency of maintenance depends on the operating conditions. Moisture and heat combined with dirt, dust, or other environmental contaminates will deteriorate the insulation, conductive materials, and protective devices in the equipment at an accelerated rate.
4. Recondition the Equipment
A more intensive maintenance option for circuit breakers is in-shop reconditioning, which should be performed when the on-site maintenance work scope cannot bring the circuit breaker within tolerances defined in current industry standards. The circuit breaker is initially tested against ANSI standards and then completely disassembled, cleaned, and inspected. Damaged parts are refurbished or replaced, and pivot points are re-lubricated before the circuit breaker is reassembled. The reconditioned circuit breaker, including the new assemblies, is retested against ANSI standards.
5. Keep Good Records and Trend Performance
Unless maintenance testing has been utilized to track the performance of circuit breakers, degradation of insulation and the moving parts may go unnoticed. Switchgear components may be out of design tolerance yet still be functional for a long period of time. Tracking test data provides a better idea of the expected life of the equipment and helps focus maintenance efforts on the areas that need it the most.
6. Upgrade the Equipment
With the advancements in circuit breaker designs, those with older technology may no longer be considered sustainable solutions. To take advantage of the more advanced technology, the switchgear lineup could be replaced. A more cost-effective alternative would be to leave the switchgear structure and bussing in place and upgrade the existing equipment with the latest state of the art circuit breakers.
7. Outsource Preventive Maintenance Via a Long-Term Service Agreement
Very few electrical maintenance or contracting companies can perform all of the required maintenance activities for an electrical distribution system. A professional electrical engineer can assist facility management with the selection of a qualified electrical maintenance contractor to develop a service agreement that addresses maintenance requirements and frequency. This ensures that maintenance will not be overlooked and standardized work scopes are used throughout the duration of the agreement.
8. Comply with the Requirements of NPFA 70E
One of the steps to comply with the requirements of NFPA 70E®: Standard for Electrical Safety in the Workplace is to “maintain all electrical distribution system components”. In fact, NFPA 70E recommends following NFPA 70B: Recommended Practice for Electrical Equipment Maintenance as well as manufacturer’s recommendations.
9. Utilize Predictive Maintenance Tools
Besides trending test data, which can be analyzed to predict equipment life and maintenance requirements, on-line monitoring tools are available that can provide warnings of impending failures. Online monitoring systems operate continually and have the advantage of recognizing a condition that may not be apparent during a one-time inspection.
10. Perform a Short Circuit Analysis and a Time Current Coordination Study
If the switchgear components do not have a proper short circuit rating, there could be catastrophic damage to the equipment and surrounding area. A short circuit analysis will determine if the switchgear is rated properly. There may also be the need to update the coordination study. Coordinated circuit breaker settings can prevent unnecessary interruptions of faults by the switchgear that should have been interrupted by a downstream device.
Electrical equipment and power distribution systems have never been designed to be or intended to remain perpetually energized without interaction by the owner. By implementing the tips covered above, you can maximize the life and reliability of your switchgear.