Electricity: Ground?

Karl Schmidt karl at xtronics.com
Thu Sep 18 15:11:16 CDT 2003


James Sissel wrote:

> Modern code requires an 8' ground rod driven below ground level AND an
> connection to the water inlet within 6' of entrance (closer is better).  The
> ground must be attached to a pipe that comes directly into the house (no
> valve between the ground and pipe).  Each ground should be an independent
> connection to the panel.  Some power companies (KCPL) require all ground
> connections in the panel.  Others want it in the meter.  Some want both.

Which electric code? There are many places where a ground rod at the 
service entrance is prohibited. The utility companies want the ground 
rod at the base of the service providing telephone pole (they want the 
utility ground to be lower impedance than your home - otherwise strikes 
to a shield wire gets diverted to your home where the voltage drop can 
be enough to break things).

In an ideal world you would have all services enter at the same side of 
the building and bonded together at one point. The biggest problem is 
that the water pipes are often a lower impedance ground than the 
electrical service cable.

Most important is to be sure you have one and only one point where you 
ground the electric service to the plumbing. Accidental ground 
connections (like where electrical conduit and plumbing contact via 
mounting arrangements) can cause problems.

  A length of plastic pipe that isolates your plumbing (except for the 
current the water itself carries) can make a big difference. Ground your 
electrical service connection to the house side of the isolated plastic 
pipe.

Kansas is not that bad for lightning problems except in spring.

Also - save you money on those suppressing outlets - the suppressor 
belongs in the breaker box. Buy ONE good one that goes there - bond all 
your service grounds (telephone, cable, water, electric) at the service 
entrance and problems disappear. (You won't get credit unless it fails<g>)

Again, you might want to look at

http://xtronics.com/reference/light.htm

-- 
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Karl Schmidt EMail    Karl at xtronics.com
Transtronics, Inc.    WEB http://xtronics.com
3209 West 9th Street  Ph(785) 841-3089
Lawrence, KS 66049    FAX(785) 841-0434

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