3phase lines

[D4V1D]

Hello

In USA using single phase lines of 120/240 and 3phase lines o 120/208.
Coexisting 2 types of lines.
it would be very esay an unique line 3phase of 127/220 V??

 

[D4V1D]

http://www.geocities.com/electrozona/fotos/selec2.jpg

My invets in my house. (from 3phase line 127/220 V)

In Spain Coexistin lines o 3x127/220 V and 3x230/400 V

David



"D4V1D"

 

[Keith Williams]

Hello

In USA using single phase lines of 120/240 and 3phase lines o 120/208.
Coexisting 2 types of lines.

No, there is only one type. Transmission is usually[*] three
phase, with transformers from that to single phase for residential
use.

[*] some older and remote areas have only single phase
distribution.

it would be very esay an unique line 3phase of 127/220 V??

Easy, sure. Unique yes, because there is no reason to do so.
Unique and *expen$ive*, certainly.

 

[Don Kelly]

----------------------------

Hello

In USA using single phase lines of 120/240 and 3phase lines o 120/208.
Coexisting 2 types of lines.
it would be very esay an unique line 3phase of 127/220 V??

120/240 single phase is used mainly for residential service. In such areas
there will be no 3 phase service at the user level. There will be higher
voltage say 12.5/7.2KV three phase but often only one phase is run down a
particular street as single phase service is adequate.
For commercial and light industry 120/208 may be used (127/220 is more
common in Canada).
Coexistence of both in the same building is not generally the case. If
400/230 is used then there will be a co-existing 120V service for small
"plug in" loads.