What is the Oil Quantity in OlTC of 100 Mva Transformer?

Answer 1

The oil quantity in an OLTC (On-Load Tap Changer) for a 100 MVA transformer isn’t a fixed number—it depends on the type of OLTC (in-tank vs. compartment type), manufacturer design, and voltage class.

That said, from a practical field perspective:

For separate-compartment OLTCs (most common in medium–large power Transformers), the oil volume typically ranges between 300 to 800 liters.

In some larger or higher voltage applications, it can go up to ~1000 liters, especially where larger diverter switch chambers are used.

For in-tank OLTC designs, the oil is shared with the main transformer tank, so you don’t calculate it separately.

The reason this oil volume matters is because OLTC oil is subjected to heavy electrical stress and carbonization due to switching arcs. That’s why it usually requires more frequent filtration or replacement compared to main tank oil.

From a manufacturer/service point of view (like what companies such as EMR Global typically address), the focus isn’t just on oil quantity but on:

maintaining oil quality through regular filtration

ensuring proper compartment sealing

monitoring carbon buildup and dielectric strength

In real operation, even a well-sized OLTC oil chamber can become a weak point if maintenance is ignored.

Answer 2

The oil quantity in an On-load Tap Changer (OLTC) of a 100 MVA transformer can vary depending on the design and manufacturer specifications. However, a typical estimate for the oil volume in the OLTC can range from approximately 500 to 1,500 liters. The total oil capacity of the transformer, including the main tank and OLTC, will be significantly higher. For precise values, it is best to consult the transformer's technical documentation or manufacturer.