The neutral earthing transformer is used to create a neutral for the delta side (which does not have a neutral point on its own). The reason you put a transformer in there instead of directly creating a neutral point and grounding it, is that you get some impedance in between due to the transformer, which would limit various imbalanced currents and fault currents to a particular value. Note that this is usually a three-phase transformer. If they are used on the star side, they are usually single-phase, and connected between the neutral and ground. You don't need a three phase device here as the neutral point already exists. Neutral earthing transformers are very common on large generators. They are used to limit bolted fault currents for these machines. They essentially allow you to insert a very small resistance (1-2 ohms) with an ampere rating of around 200A to restrict line-to-ground fault currents for the generators to around 1 - 2 A. They are indispensable for this purpose. Chemical Earthing Supplier in Noida Chemical Earthing Manufacturer in Noida Chemical earthing supplier in gurgaon Chemical earthing supplier in Haridwar Chemical earthing supplier in Delhi