Carlos E. R. wrote:
The Tuesday 2006-10-24 at 07:37 -0400, James Knott wrote:
Where do they have 110 V~ ??? North America. Here we have a 240/120V distribution system. You'd use 120 for small appliances, lighting etc. and 240 for heavy appliances such as stoves etc. The power feed to homes is 240V with a grounded center tap or neutral, so there's 120V either side of neutral.
Dual phase? Curious.
Here (Spain) we have a three phase system. Voltage is 230 (was 220) live to neutral, with 230*sqroot(3) = 400 Volts from phase to phase. We have 230 for homes, and 400 (3 phases) for industries and heavy loads like lifts or air condiotining.
We also have 3 phase with 120V to neutral and 208 between phases. However, to get the 120V the 240V load side of the transformer has a center tap, that is grounded. Either side to neutral is 120V. This has the advantage where current in one side balances current in the other, reducing the current in the neutral, thus reducing resistance losses in the wiring.