Preventive Maintenance and a regular transformer oil testing can help identify potential issues and timely repair well before a unit fails.
Breakdown of a power transformer can lead to lost revenues in millions, as a replacement can take months to procure and install. Worse, a broken transformer can trigger fire and explosions, endangering and threatening critical assets, including the workforce.
Fortunately, losses due to transformer breakdown can be avoided through preventive and predictive maintenance and testing.
Periodic analysis of transformer oil is necessary to monitor engine conditions, state of turbines, and oil lubricated equipment. The same is applicable for transformer oils used for insulating transformers, distribution transformers, and related electrical distribution equipment. Regular analysis of transformer oil provides information on the oil and helps detect the onset of other possible problems, including ageing insulating paper and contact arcing.
In the last two decades, the importance of preventative maintenance in electric power distribution sector has shot up. Such equipment does not develop snags frequently, but when a power transformer fails, the results can be severe, more so in setups like an electrical substation. Apart from safety risk, there can be high repair costs too. By analyzing chemical and properties of oil, and concentrations of specific dissolved gases, issues related to such transformers can be evaded. Involvement of veteran electrical consulting engineers can be helpful in this regard.
Listed below are the common tests carried out on electrical insulating oils.
- Humidity: A vital function of transformer oil is offering electrical insulation. So, the rise in moisture content may diminish the insulating properties of such oils. If the transformer cools down, the dissolved water is freed, leading to dismal insulating power.
- Dielectric or Insulating Strength: Transformer oil’s dielectric strength is defined as the highest limit of the voltage applied through the fluid sans electrical breakdown. As these oils are made to offer electrical insulation, dielectric strength reduction is not desirable.
- Acid Value: Transformer oils get oxidized owing to oxygen and excessive temperature, leading to an increase in Acid Number. The formation of carboxylic acids causes this. In the long run, this can affect the cooling of the transformer adversely. Oil degradation also generates acids, changing the oil’s insulating properties.
- Power Ratio: In a transformer, high power factor indicates considerable power loss in its insulating oil. Contaminants like oxidized oil and water cause it.
- Dissolved Gas Analysis (DGA): DGA is essentially deployed to find out concentrations of specific gases in the oil. These include carbon monoxide, nitrogen, oxygen, hydrogen, ethane, methane, ethylene, and acetylene. The concentrations, as well as ratios of such gases, are useful to diagnose transformer operational problems. If the carbon monoxide level is high, it may indicate cellulose paper thermal breakdown, for instance.
- Furan Compounds: Heterocyclic organic compound or furan derivatives are used to assess cellulose paper degradation. With time, the paper’s degree of polymerization goes down. Its mechanical strength also goes down.
Similar to the analysis of machinery oil, analysis of electrical insulating oil is essential for thwarting unscheduled outages in critical electrical distribution equipment. These analysis and tests can be vital in industrial electrical setups in particular. The tests reveal the condition of the transformers and the oils used to lubricate and regulate the temperature. For oil- filled electrical equipment like transformers, routine oil analysis is included in predictive and preventive maintenance programs.
While preventive maintenance and analysis of transformer oils are crucial for snag-free operations, it is also necessary to buy transformers from the right manufacturers. You should choose from the top electrical contractors in Delhi NCR region.
Singh ISO Tech is among the top entities in this sector and offers transformer installation across India. You can get high-quality transformers from the company at approximately 25% lower price than other vendors. Moreover, Singh ISO Tech can be trusted for all types of power transformer installations, as they are a Business Network International (BNI) member.