Three #3/0 copper wires can be installed in an 1 1/2" conduit. If it is a service entrance distribution it is better to use a 2" rigid conduit so that all of the materials connect together properly.
UK answer: The transformer would be rated in VA so on a 3-phase 415 v system at 200 amps the rating is 144 kVA, enough for 50-70 houses depending on local usage.
A 3/0 copper conductor with an insulation factor of 90 degrees C is rated at 225 amps.
to determine the transformer characteristics...
Any where that a three phase supply distribution is needed to operate three phase equipment.
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.
It depends on whether you are wye or delta connected. A transformer is a transformer, and a three phase transformer is simply three transformers. The key is in how you hook them up.AnswerIt depends on how the transformer is connected. If one set of windings is connected in star (or wye), then the star point is/canbe earthed and becomes the neutral for that particular connection; this is the standard connection for the secondary (low-voltage) of European distribution transformers. In North American three-phase distribution transformers, the secondary windings are connected in delta, and one phase is centre tapped, earthed, and that becomes the neutral point for a 240/120-V split-phase supply to a residence.This answer applies to both three-phase transformers, and to single-phase transformers which have been connected to form a three-phase transformer bank. (It is incorrect to say that a three-phase transformer is simply three single-phase transformers!)
That is the maximum efficiency occurs when the copper losses are equal to the core losses of the transformer.
Harmonics are really not needed in single phase transformers.
This depends on the voltage, and whether it is a three phase or single phase transformer.
By having a transformer with 3 phase input and single phase out put
If it's a split-phase system with centre-tapped transformer, then two ammeters are needed, one on each side.
Your question is rather vague. If you are asking what do you call a group of single-phase transformers, connected to supply three phase, then the answer is a 'three-phase transformer bank'.
A single-phase transformer works with a single-phase supply, while a 3-phase transformer is used with a 3-phase supply. A single-phase transformer has 2 wires on the primary and secondary (ignoring taps) while a 3-phase tansformer has 3 or 4 wires on the primary and secondary.
By design are you going to wind the transformer yourself? In your design you need a 5:1 ratio. On the output side of the transformer any two legs of a three phase transformer is considered single phase voltage. Good luck on your project.
to determine the transformer characteristics...
A three-phase transformer bank is often used in power stations because it is easier to construct and transport very large single-phase transformers, compared with constructing and transforming an equivalent-capacity three-phase transformer.
with an meg ohm meter
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.
..the questions does not say wether the 30kVA transformer is 3 phase transformer or single phase transformer..but it is implying that a single phase welding load at 16A per phase is to be connect to it, it is assumed then that the transformer is 3 phase transformer..we assume load is rated 240V.. ..though not much details is given about the transformer voltage specs. but if is rated 3 phase 415/240V, the approx full load current per phase is given by 30KVAx1.3912=41.736A.. ..but if the transformer was rated single phase 240V say, the approx full load current FLC=30000/240V gives 125ampers.. ..if you further devide the FLC by the intended load current.. ..Recommended no of welders per for a 3 phase 415V transformer and assuming single welding sets =41.736/16=2.6..so you can connect max two welding sets to this transformer per phase,..max 6 weld sets can connect at an approx load factor of 76%.. ..for the single phase transformer, FLC/16=125/16, gives 7.8 but is also recommended not to connect more than 6 welding sets to such transformer for the same reasons..