Preventive and Regular Maintenance

Preventive and regular manages of components of the distributions system is necessary to reduce/eliminate breakdowns. Care should be taken to optimize preventive maintenance, since each shutdown due to preventive maintenance is also a source of revenue loss.

Preventive maintenance could be minimized through careful design and healthy installation practices. The following activities should be undertaken for preventive manages:

• Maintenance of overhead lines that needs removing/trimming of trees along a sufficiently huge right-of-way to prevent their possibly damaging the line. The creepers and bird nests should also be removed.
• Repairing of broken or damaged cross-arms, conductors, insulators, and supports should be completed on a regular basis.
• Bending or leaning of poles should be corrected and stays should be tightened.
• Transformer oil testing for moisture level, sludge and BDV. Further a periodic gas chromatography will help to identifying incipient/developing faults in a transformer.
• Improved bushings: High creepage distance bushings along with 50% protected creepage could serve as a better solution. Having multiple connections at the bushing is a damaging installation practice causing higher outages.
• Monitoring a temperature of the transformer tank: In case the tank is hot, the transformer should be de-energized and tested.
• Rewinding of transformer: This always leads to higher no-load and operative losses. Higher losses after rewinding should not be permitted.
• Protective devices such as switches, circuit breakers, relays, fuse and lightning arrestors, and etc. should be used to protect the distribution system and temptation to bypass it must be avoided.
• A neutral of the transformer should be solidly grounded to avoid neutral shifting and to permit the zero sequence currents to be earthed.

Maintenance planning and schedule creation helps to reducing the interruption of supply because of breakdown and ensuring the whole health of the distribution system.