3 Phase Distribution Transformer Diagram
The common terminal is indicated by suffix 1 in the figure below.
3 phase distribution transformer diagram. Phase wiring for y y. Phase wiring for y y transformer. I need a 3 phase distribution transformer 10 15 kva to provide 120 volts power to appliances. Load is a 3 phase induction motor 25hp 240v 60hz and a heater load of 4kw 240v single phase.
Figure 1 is a schematic diagram of a distribution transformer for 120 240 v single phase service the 240 v is obtained by making connections between the two ungrounded hot conductors and the 120 v is obtained by making connections between either of the two. If terminal with suffix 1 in both primary and secondary are used as common terminal voltages of primary and secondary are in same phase. Figure 1 secondary of a single phase transformer provides 240 v across a and b and 120 v across either a or b and the neutral. In a delta connected dd group of transformers the line voltage v l is equal to the supply voltage v l v s but the current in each phase winding is given as.
A three wire three phase circuit is usually more economical than an equivalent two wire. Compute the kva required. Transformers 15kva and higher that meet doe 2016 legislation will help lower operating costs lower cost of ownership increase profitability and reduce overall greenhouse gas emissions. The invention of a practical efficient transformer made ac power distribution feasible.
A distribution transformer or service transformer is a transformer that provides the final voltage transformation in the electric power distribution system stepping down the voltage used in the distribution lines to the level used by the customer. Y y y y and. Motor from table 2 the current is 68a. First i ll show the wiring connections for a y y configuration.
Three phase electric power is a common method of alternating current electric power generation transmission and distribution. Three individual transformers are to be connected together to transform power from one three phase system to another. A system using distribution transformers was demonstrated. Inputs a 1 a 2 a 3 may be wired either δ or y as may outputs b 1 b 2 b 3.
Three phase transformer connections a three phase transformer is built for a specific connection and voltage transformation and the unit will have a nameplate with the internal connections shown. When a single unit or bank of three is used there are four types of connections. 240v x 68a x 1 73 28 2 kva 1000 the kva can also be obtained from table 3 heater 4kva a 3 phase transformer must be. The connection diagram on the left shows how a delta delta connection can be made either with three single phase transformers or with one three phase transformer.
The four basic connections are. It is a type of polyphase system and is the most common method used by electrical grids worldwide to transfer power. It is also used to power large motors and other heavy loads. Star star transformer is formed in a 3 phase transformer by connecting one terminal of each phase of individual side together.
1 3 i l of the line current where i l is the line current. The power available is 3 phase 240 volts line to neutral.