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What is a Transformer Breather? A transformer breather (silica gel breather) is a simple device that keeps moisture out of the transformer. We fit it to the pipe coming out from the transformer conservator tank. When the transformer heats up, the oil expands. When it cools down, the oil contracts. This creates a breathing action. … Read more
The Buchholz Relay is a gas-actuated protection relay. It is a mechanical relay. All oil-immersed transformers that have a conservator tank should be equipped with a Buchholz relay. A Buchholz relay can detect both slow-developing faults and major transient faults occurring within the transformer. It provides an early warning (alarm) for slow-developing faults and initiates … Read more
An Oil Surge Relay, or OSR, is a type of mechanical relay. It operates in response to a sudden oil surge. Need for Separate Diverter Tank Every modern power transformer includes an On-Load Tap Changer (OLTC). During tap-changing operations, some arcing always occurs at the diverter switch contacts. It is desirable to change tap positions … Read more
Transformer oil is a special type of refined petroleum oil. It provides both insulation and cooling to electrical equipment. Additionally, we utilize insulating oil in power transformers and distribution transformers. We fill the gaps between the core, windings, and interior of the transformer tank with this oil. The presence of oil in the gaps enhances … Read more
Transformer oil plays two major roles inside a transformer. It strengthens the electrical insulation between live parts and between live and dead parts inside the transformer tank. It also removes heat from the core and windings by carrying the heat to the radiators. To perform efficiently, transformer oil must possess several important properties. Each of … Read more
Breakdown Voltage (BDV) of Transformer Oil Breakdown Voltage (BDV) indicates the voltage above which an oil electrically breaks down. According to IS 335, new unfiltered transformer oil should have a breakdown voltage above 30 kV (rms) when tested with a 2.5 mm gap. For filtered new transformer oil, it is greater than 60 kV (rms) … Read more
The Nitrogen Injection Fire Protection System (NIFPS) prevents and extinguishes fires in oil-filled transformers. Thereby, it safeguards critical power infrastructure. We also commonly call it the Nitrogen Injection Fire Prevention & Extinguishing System (NIFPES). This system operates on a “drain and stir” principle, effectively mitigating fire hazards through a coordinated sequence of actions. Working Principle … Read more
Current Transformers are essential for protection and measurement. To work correctly, they must reproduce primary current in a fixed ratio on the secondary side. However, CTs are not ideal. They suffer from three major types of errors. Ratio Error (Magnitude Error) in CTs The CT can not produce the exact scaled-down current. The actual secondary … Read more
A watt-hour meter-type induction relay is essentially a variant of an electromagnetic induction relay. Instead of only current or only voltage, it operates depending on the power input to the relay. Obviously, these relays require both the voltage and current of the system to operate. Power is the product of voltage, current, and power factor … Read more
A static electrical relay is a protection relay. It uses solid-state electronic circuits. Additionally, it does not contain any electromagnetic coils or moving parts. Therefore, we refer to it as a static relay. Basic Structure of an Electrical Static Relay A static relay operates using electronic components and circuits. For example, these components include diodes, … Read more