A tap changer is a device that changes the number of turns in one winding to regulate voltage from an electric transformer. There are two types: de-energized and on-load. The former needs no energy input, while the latter does need power just like any other electrical component – it must be switched on before use!
In this post we'll cover:
What are the advantages of tap changing transformer?
Tap changing transformers are advantageous because they can provide voltage control for the transformer without de-energizing it, which means you don’t have to worry about blowing any fuses by accident. Tap changer transformers also increase efficiency and allow adjustment of reactive power flow in accordance with demand requirement at a given time.
Why tapping is used in transformers
Transformers can be provided with a tap to adjust the turns ratio for when there is an input supply variance. This will allow the output voltage to come closer to its rated value even if it’s not quite at that rating due in part because of where you are measuring from on your transformer, which varies depending on what type and number of windings exist around each coil.
What are the disadvantages of a tap changing transformer?
The disadvantage of a tap changing transformer is that the load must be shut off when it’s time to change taps. This type of transformer gets its name from this function, as in “offload” or without power so you can fix something on your equipment and then turn back on once work has been completed. The downside with having an arrangement like Figure 1 is because there isn’t any way to use it for loading while performing transformations, which means more expensive parts are needed if repairs need done during operation!
Why do we have to remove load from an off load tap changing transformer before taps are changed?
In order for the change in voltage and current to be safe, it is important that all of the power or energy stored inside a Transformer’s coils has been released. In case of Off-Load Tap Changer, if one tries to make changes while still storing electricity – heavy sparking will take place which can damage any insulation as well as hinder expensive repairs on equipment.
I'm Joost Nusselder, the founder of Tools Doctor, content marketer, and dad. I love trying out new equipment, and together with my team I've been creating in-depth blog articles since 2016 to help loyal readers with tools & crafting tips.