Key learnings:
Emergency Preparedness: Understanding and implementing the maintenance schedule helps prevent breakdowns, enhancing system reliability.
Transformer Importance: Transformers are crucial for effective power distribution and require diligent maintenance to function properly.
Transformer Maintenance Checklist: A structured approach to maintenance—covering daily, monthly, and yearly tasks—ensures long-term transformer health.
Diagnostic Testing: Regular tests like oil quality checks and Dissolved Gas Analysis are vital for preventing transformer failures.
Preventative Maintenance: Routine inspections and maintenance reduce the likelihood of emergency interventions and extend the transformer’s operational life.
A power transformer is the most costly and crucial piece of equipment in an electrical substation. Therefore, it’s important to carry out various preventative maintenance activities to keep it performing well and extend its functional life.
A power transformer requires various routine maintenance tasks including measurement and testing of different parameters of the transformer. There are two main types of maintenance of transformer. We perform one group on a routine basis (known as preventative maintenance), and the second group on an ad-hoc basis (i.e. as required).
This means to ensure smooth performance from a transformer, regular maintenance actions are necessary.
Some other types of maintenance for a transformer we perform only as they are required – known as emergency or breakdown transformer maintenance. But if one performs regular maintenance properly, this significantly reduces the chances of needing to perform such emergency maintenance. The regular checking and maintenance of transformer is also known as condition maintenance.
Hence by proper condition maintenance, one can avoid emergency and breakdown maintenance. That is why technical personnel should mainly concentrate on condition maintenance. As 100% of condition maintenance causes 0% breakdown of equipment.
There are many different preventative maintenance actions to be performed on a power transformer. They can be on a daily, monthly, yearly, quarterly, half-yearly, or yearly basis. Some transformer maintenance activities only need to be performed once in a 3 to 4 years interval.
Monthly Basis Maintenance of Transformer
Let us first discuss about the action to be taken on power transformer in monthly basis.
- The oil level in oil cap under silica gel breather must be checked in a one-month interval. If it is found the transformer oil inside the cup comes below the specified level, oil to be top up as per specified level.
- Breathing holes in silica gel breather should also be checked monthly and properly cleaned if required, for proper breathing action.
- If the transformer has oil-filled bushings, the oil level inside these bushings must be visually checked monthly using the attached oil gauge.