[TowerTalk] CQ article error(?)

Jim Lux jimlux at earthlink.net
Fri Oct 7 13:50:00 EDT 2005


At 10:09 AM 10/7/2005, Gary Schafer wrote:


> > I disagree- the SPG and household wiring are inseparable because all the
> > conductors in the house are related to ground by the neutral and safety
> > ground wires.
>
>No they are not! Neutral and safety ground are two separate and distinct
>circuits. They are only common at the main disconnect in the house. The
>purpose of them being separate is so no neutral current ever flows on
>the ground wire.


More to the point.. the neutral conductor should be considered as a power 
conductor (i.e. the same as the hot). It is NOT part of the grounding 
system in any way.

Somewhere in the system you need to provide a ground reference between 
earth ground (that upon which the potential shock victim stands) and the 
power line conductors, mostly to limit the maximum differential voltage and 
to provide a path for capacitively coupled currents. It's also useful 
because it reduces the shock hazard for certain two prong plug devices 
(i.e. light bulbs) because they hook the more easily touched part to the 
neutral.. it also makes it possible to use single pole switches without 
creating a huge safety hazard.

But, there should be ONE and only ONE interconnection, otherwise, the 
grounding system (which is there for safety) carries load current and that 
is just plain old bad.







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