[Boatanchors] Storm Damage to Electronics

[rbethman]

Sheldon,

Yes, there is an entirely different methodology/mentality in Europe, 
Asia, and Middle East.

One exception that I know of would be Korea.  However, this is due to 
the very close nature of their systems and our assistance since the 
Korean War.

The U.S. has its methodology/mentality in a different direction.  Long 
haul distribution is mostly in Delta. Long haul distribution is also 
125KV on the low end, and 250KV or much more.  Once it hits the 
substations, then they break it down to WYE for primarily residential, 
and for the normal voltages used in homes.

U.S. Generation is *almost* exclusively WYE.  There are few exceptions.  
They use relays to sense excess ground current.  This normally indicates 
a transmission fault, or VERY large load imbalances.

They use the three phase for the large commercial loads.

We see the line voltages in the home around 125 to 127 line to 
ground/neutral.  Most folks don't even realize that ground and neutral 
are bonded to the frame of the service entrance panel.  This is the ONLY 
place that it occurs.

GFCI circuits are now required.  That is where the "safety" grounds come 
into play.

Bob - N0DGN

On 11/9/2011 4:42 AM, Sheldon Daitch wrote:
> Bob,
>
> Outside the US, three phase in residential structures is
> far more common.
>
> In Morocco and in Kuwait, both places we lived in
> had three phase 240/416.
>
> In our Morocco residences, it seems the three phase
> was simply the common wiring convention, but in
> Kuwait, the air conditioners for the house are large
> enough that they have three phase compressors.
>
> The GE flat top stove we have is a standard stateside
> stove, and in the US, operating the stove off the standard
> 240VAC with center tapped neutral, there was always a
> 120VAC line to neutral.  When GE ships these as an
> export model for the 240V phase to neutral world, they
> have to add a transformer to get the 120VAC for the
> electronics board in the unit.
>
> 73
> Sheldon