[Heathkit] ground

[Kenneth G. Gordon]

On 6 Dec 2007 at 11:54, WB6BLV  Central California wrote:

> whenever I run electrical to new construction, I run only three wires
> for 220... the two hot sides and the neutral/ground... so far the
> electrical inspector has signed off all of it with no hesitation, even
> though I am not convinced the national code is being met...

It is not. Perhaps your inspector is not up on the latest 
electrical code. It now requires separate ground and neutral 
wires.

> frankly,
> my concern in any 3-wire 220 system is that the neutal must carry the
> full current of BOTH sides when they are split into 2 separate 110
> sets of circuits...

 No, that is not correct. If both sides of the 220 Volt line are 
equally loaded, there will be NO current in the neutral, since 
the two phases are 180 degrees out of phase. Therefore, 
current in the neutral cancels. 

Similarly, if ONE side of the 220 volt line is loaded, and the 
other has no load, the neutral carries the same current as 
the loaded side. Therefore, the neutral never carries any 
more current than one hot lead.

> and it is often NOT larger guage wire that the two
> hot wires...

Correct. It doesn't have to be larger.

Ken Gordon W7EKB