Abstract: This paper is a research based on the upcoming type if transformer which is a dry type transformer or commonly known as Cast resin transformer. The study focuses on the manufactu ring process of producing transformer as well as the design and temperature control relay. Moreover the advantages using dry type transformer over the other types will be analyzed. The transformer is also widely used its load for maximum power transfer, is olating one circuit from another, or isolating direct current while maintaining ac continuity between two circuit. In this paper, the design of 315 kVA, 11/0.4kV dry type distribution transformer is discussed. Rectangular wire is used in low voltage windin g as well as round wire is used in high voltage winding in this transformer design. Dry type are normally cooled by natural circulation of air and also the type of epoxy material that is used on the windings help minimize the heat dissipated by the copper when the transformer is loaded. Keywords : Transformer Design, Temperature Control Relay, Cooling System, Dry Type, Round And Rectangular Wires. I. INTRODUCTION Transformers are electric equipment that changes the voltage and the current of electrici ty to facilitate its efficient transmission and distribution. Transformers are commonly use at power generation facilities to increase voltage and to decrease current in order to transport electric energy across transmission lines. When the electricity rea ches the end user, transformers are used to reduce voltage and to increase current to make the electricity suitable for general use. The process of transforming voltage results in energy loss that is released in the form of heat and therefore transformers must contain effective cooling systems. Dry type transformers dissipate heat directly into the ambient air. Liquid cooled transformers dissipate heat into liquid mediums. Dry type transformers require little or no maintenance through their service life oth er than assuring that connections remain clean and tight, that the loading on the transformer remains within design limits, and that air flow through the transformer is not impeded by extraneous materials or dust. Dry type transformers are therefore th e primary choice for indoor locations, and can be used anywhere a transformer is required. Dry type transformers are replacing liquid immersed transformers in many commercial and industrial applications including power plants, hospitals, schools, multi sto ry buildings, paper and steel mills, mining, chemical plants and subway systems. There are many types of dry type transformer. Some of dry type transformers are Cast resin dry type transformer Gas filled dry type transformer Epoxy coated dry type transform er RESIBLOC epoxy cast type transformer Vacuum pressu re impregnated conventional dry type transformer and so on. II. CAST RESIN DRY TYPE DISTRIBUTION TRANSFORMERS Cast resin dry type transformer is a transformer which one of the dry type transformers a s shown in Fig.1 . A cast resin dry type indoor 3phase, 315kVA, 11/0.4 KV, Dyn11, distribution transformer has been developed. This transformer is of IP00 protection degree This transformer is the most suitable transformer for distribution of electricity in high degree of safety. They do not propagate fire. They are self extinguishing and in the event of a break down, there is no risk of leakage of inflammable or contaminating substances such as oil. The thickness insulation pouring with transformer, with thi ck insulation transformer is filter casting resin encapsulation winding transformer, cast resin plus quartz powder as casting, quartz powder 60%, only 40% of resin and pigment of the product. Thickness of epoxy resin before casting in general 6~12 mm, now 3~ 5 mm, thick insulation pouring it said transformer. Flame retardant, self extinguishing, good, high mechanical strength. In a two winding transformer two windings would be present. The one which is connected to a voltage source and creates the flu x is called as a primary winding. The secondary winding where the voltage is induced by induction is called a secondary. If the secondary voltage is less than that of the primary the transformer is called a step down transformer. If A YE A YE P YONE , M YO T HET T UN International Journal of Scientific Engineering and Technology Research Volume.0 3 , IssueNo. 1 7 , August 201 4 , Pages: 3500 350 4 the secondary voltage i s more than it is a step up transformer. A step down transformer can be made a step up transformer by making the low voltage winding its primary. Hence it may be more appropriate to designate the windings as High Voltage (HV) and Low Voltage (LV) windings. The high voltage and low voltage coils are wound of either copper or aluminium conductor which are suitable for class F and class H insulation systems. The coils are completely impregnated and cast under vacuum in fiberglass reinforced epoxy resin into th e moulds. The casting process produces an insulation system of uniform fiberglass epoxy laminate. The final product is a composite of highest electrical and mechanical quality. The windings are embedde d into the first class lamina Fig.1. Cast resin dry ty pe transformer [3] . A. Basic Parts of Cast Resin Dry type Transformer a) Core Fig.2 presents the c ore is made of cold rolled electro technical sheet steel with a heat proof coating. Stacking technology and step lap cutting provide low level of no load losses. Cutting of lector technical steel is carried out on the automatic cutting line with the high cut accuracy. Fig . 2. Stacking core . b ) High And Low Voltage Windings High voltage windings are made in layer or section layer form with the series conne ction of sections forms. Low voltage winding are made in foil or layer form. HV and LV winding is made of insulated wire on high accuracy coil processing machines. Vacuum resin filling of windings is carried out during a completely automated process. E poxy compound includes a number of components providing a good heat emission, and also a high thermostability. c ) Transformer Windings Windings form another important part of transformers. The windings of the transformer are normally arranged in the f ollowing two ways: Concentrically in relation to one another (used for core type) and called concentric winding. In group of LV, HV coils stacked alternately one over the other, along the height of the limb (used for shell type) and known as interleaved w inding or sandwich winding. Most commonly used types of winding in transformers are the following: Cross over winding Continuous disc coil type winding Disc type section winding Helical winding Sandwich winding (for shell type transformer) Dry type/ Cast resin [1] d ) Transformer Housing Transformer housing provides necessary protection degree of the active part. It is made of steel construction with walls, a bottom and a roof. The walls and the bottom havevent holes, providing a normalized cooli ng level of the transformer. Wide walls have access panels for access to adjusting taps. Al walls are deta chabled that assures visual inspection and maintenance service on a schedule date. Transformers can be manufactured of the following design versions: Lеft: HV winding inputs are on the left regarding the front; Right: HV winding inputs are on the right regarding