I think you mean 'winding', rather than 'phase'? The cross-sectional area of the conductor must be such that it can carry whatever current the winding is designed to carry -if the current is low, then the cross-sectional area (and, hence, its thickness) can be low.
If these are the exact voltages that you need you will need an auto transformer to obtain these voltages. If these voltages are nominal voltages and are of a three phase four wire configuration, the 220 voltage can be obtained from the three phase legs to the neutral (ground) connection. The equation to use is 400/1.73 = 231 volts.
yes
the necesscity of two three phase transformers operating in parallel are as follows...if the one transformer fails to give supply,then another transformer can be used in parallel and hance,continuity of supply can be maintained.one transformer can be easily take out from the supply for repair & maintanance.if the load on the substation increases beyond the rated values of transformer, then another transformer can be used to share rhe load of the substation.
Your question doesn't describe under what circumstances the transformer is being used. Normally, a two wire (hot and ground) AC voltage can only be a single phase supply. Look up the explanation of how AC current cycles on a sinewave (60Hz is 60 sinewave cycles per second). This is also known as a single phase. Coming into a standard residential house is a three wire line with two hot wires and a ground wire. The two hot wires are out of phase with each other (opposite sinewave). A standard transformer can have multiple outputs with various/same voltage. Look up how a transformer works. Without special electronic components for each output circuit, all taps will be in phase. A transformer outfitted with the special electronic components is very expensive and not for normal everyday use.
Yes, you can use three single phase transformers on three phase applications and interconnect them to serve as a single transformer or you could use one single phase transformer fed from two of the three lines in a step down application.
If these are the exact voltages that you need you will need an auto transformer to obtain these voltages. If these voltages are nominal voltages and are of a three phase four wire configuration, the 220 voltage can be obtained from the three phase legs to the neutral (ground) connection. The equation to use is 400/1.73 = 231 volts.
A three phase four wire system allows for two voltages from a single three phase transformer. The transformer configuration is a wye or star connection. It is used in commercial and industrial applications. Apartment buildings are now starting to use a three phase four wire service distribution system. Some wye connection voltages are 120/208 volts, 480/277, and 600/347. The lower voltage is derived from the sq root of 3 divided into the three phase voltage.
If the primary and the secondary windings of the three phase transformer are connected in delta, you cannot get a healthy neutral from it but why bother? You simply drive a rod into earth and use it as a neutral. Alternatively either the primary or the secondary windings must be connected as star and you use the common point as neutral.
yes
the necesscity of two three phase transformers operating in parallel are as follows...if the one transformer fails to give supply,then another transformer can be used in parallel and hance,continuity of supply can be maintained.one transformer can be easily take out from the supply for repair & maintanance.if the load on the substation increases beyond the rated values of transformer, then another transformer can be used to share rhe load of the substation.
The normal way is to use a transformer with a 3-wire primary and a 4-wire secondary. In the UK that happens at electricity substations for example where the 11 kV supply comes in on 3 wires and goes out at to users at 240 v with three phase wires and a neutral.
Rephrase your question. As it stands, it makes no sense.
Your question doesn't describe under what circumstances the transformer is being used. Normally, a two wire (hot and ground) AC voltage can only be a single phase supply. Look up the explanation of how AC current cycles on a sinewave (60Hz is 60 sinewave cycles per second). This is also known as a single phase. Coming into a standard residential house is a three wire line with two hot wires and a ground wire. The two hot wires are out of phase with each other (opposite sinewave). A standard transformer can have multiple outputs with various/same voltage. Look up how a transformer works. Without special electronic components for each output circuit, all taps will be in phase. A transformer outfitted with the special electronic components is very expensive and not for normal everyday use.
Yes, you can use three single phase transformers on three phase applications and interconnect them to serve as a single transformer or you could use one single phase transformer fed from two of the three lines in a step down application.
Nothing. The same rating is applicable.
Use a transformer.
Generally speaking high-voltage three-phase systems are three-wire systems comprising three line conductors, so the high-voltage primary of the transformer is delta-connected (a delta connection has only three terminals, to which the three line conductors are connected). European low-voltage three-phase systems are four-wire systems, comprising three line conductors and a neutral conductor. To obtain this, the transformer's secondary must be star (wye) connected, with its earthed star point providing the neutral.