The On-load tap changer (OLTC) transformer, also known as On-circuit tap changer (OCTC) transformer, is a critical component in electrical power systems. It is designed to provide a continuous and reliable power supply without interruption. This type of transformer is equipped with an intricate yet costly mechanism known as on-load tap changing which allows it to make the necessary changes while in use, making it ideal for high-power applications such as motors or large appliances.

OLTC transformers are used to regulate the voltage of high-power electrical systems. They can automatically adjust the voltage output by changing the number of turns in the transformer's primary or secondary winding, depending on the level of incoming voltage. This is done without interrupting the power supply, making it ideal for applications where continuity of power is critical.

In terms of construction, OLTC transformers are similar to conventional transformers, but they come equipped with a tap changer mechanism that enables them to adjust the voltage output without disrupting the power supply. The tap changer consists of a set of switches that are used to connect the transformer winding to different taps, which are located at different points along the winding. These taps can be adjusted manually or automatically, depending on the application.

OLTC transformers are available in various sizes and voltage ratings to suit different applications. The present product range of KVA Process Transformers includes ASVRs in 6 KV, 11 KV, 33 KV & 66 KV, system and up to 50 MVA. We also manufacture tailor-made equipment as per the specific requirements of our customers.

Product Details:

Our OLTC transformers are available in three types:

• OLTC Fitted Transformers: These transformers are equipped with an OLTC mechanism that allows them to adjust the voltage output automatically without interrupting the power supply. The OLTC panel's voltage sensing relay ensures that the appropriate tap is chosen, resulting in a regulated output voltage.


• OLTC with Star-Connected Auto Transformer: If the input voltage is more than 20% of its rated value, then an On-Load Tap Changer (OLTC) should be installed along with a star-connected high voltage auto transformer that has suitable taps. This must be placed in the same cabinet as the step-down transformer. The OLTC panel is fitted with a Voltage sensing relay that automatically selects the correct tap and supplies HT voltage, adjusted to within (+/- %) of the autotransformer's output, to the step-down transformer.


• OLTC with Regulator: If a regular step-down transformer was already installed, or if it has an extremely large capacity (over 2 MVA), the regulator will be put in a different cabinet. A regulator of this sort is composed of an auto transformer with OLTC Control. The Voltage from the regulator is then passed on to the step-down transformer, thus providing reliable and regulated HT power.

This is the latest iteration of a high voltage (HV) regulator, designed to efficiently correct any fluctuations in HV supply. It is available in 4 different voltage ranges of 6KV, 11KV, 33KV & 66KV, and utilizes an ON LOAD TAP CHANGER SWITCH to regulate the supply voltage. Our OLTC transformers are reliable, efficient, and designed to meet the unique needs of your power system.