Buchholz relay – Working Principle, Construction and Operation

A Buchholz relay in a transformer is an oil-activated relay, used to sense abnormalities such as short circuits, overheating, and oil leakages inside a transformer. It is a cylindrical object found in the pipe connecting the conservator to the main tank, in large oil-immersed transformers. It is very common in all oil-immersed transformers rated higher … Read more

What will happen if a DC voltage is applied to a transformer coil?

This is a quite common question asked by many. In fact, it is necessary to know why we don’t apply DC voltage to a transformer coil. You may come across the same question during interviews too. This article can help you clear your query.  Well! Here is the answer: Before explaining what will happen if a … Read more

Why are current transformers used in power system?

Why are current transformers used in power system? Protective relays coils and measuring instruments such as an ammeter, watt meter and energy meter are very sensitive devices and cannot be directly connected to the line carrying high magnitudes of current. So, we have to reduce the magnitude to a lower value and equivalent to the … Read more

Which is the most efficient electrical machine?

The most efficient electrical machine is the transformer. Transformers have efficiency above 95%. The autotransformer has an efficiency of close to 98%. The maximum efficiency is achieved under the fully loaded condition. Read More about Transformer: Electric Transformer