Re: Surge Protection?

[w_tom <w_tom1@xxxxxxxxxxx>]

  A knot in a wire will increase inductance.  Inductance means
a transient will be attenuated.  Therefore that inductance is
lightning protection - if we ignore the numbers.  We apply
numbers.  Now that inductance is so trivial as to attenuate by
almost zero amount.

  This demonstrates the problem with those who make
recommendations and cannot provide numbers.  Once we apply the
numbers, then reality puts those claims into perspective.
Claims made without numbers is akin to 'lying by telling half
truths'.   A wire knot is surge protection .... useless surge
protection because it will not sufficiently stop or block what
even three miles of sky could not accomplish.

  Wire inductance is also why that 30 foot connection to a
water pipe is not effective earthing for the 'whole house'
protector.  So that lightning does not seek other paths to
earth via household appliances, that earthing wire from 'whole
house' protector to the single point earth ground must be
short, direct, and independent.  Short as in 'less than 10
feet' to minimize inductance.  Direct as in no splices, no
sharp bends, and not inside metallic pipe or conduit; again to
minimize inductance.  The protector is only as effective as
its earth ground which is why wire impedance to earth must be
minimized.

  Minimum wire inductance from each incoming utility wire to
earth ground (either via a 'whole house' protector or by
direct wire) is for transistor safety.  Wire inductance is not
relevant when earthing for human safety.  Wire inductance is
why earthing for transistor safety often must exceed National
Electrical Code (NEC) requirements.

  A water pipe ground must remain (and is required) for human
safety.  Any wire that connects to a water pipe must remove
electricity from that pipe.  Any electricity accidentally
shorted to water pipes - either inside the house or outside -
would be shunted to electric box safety ground.  That water
pipe connection is a human safety ground and is too long (too
much impedance) for transistor safety ground.

  00 gauge wire to earth ground may be much larger than
required.  The typical residential earth ground - for both
human safety and for transistor safety - is often large enough
at 4 AWG.  Sounds like by going through the foundation rather
than over it, you have installed a superior earthing
connection; shorter connection with less wire bends.

mikey wrote:
> I lost you with the knot thing. Are you just plucking this from
> your cranium or a particular book, article or what have you? I've
> always found thus a fascinating subject if there's more to read.
>
> I'm planning on whole house protection here and wasn't happy
> with the water inlet 30 ft away so I dug down outside the panel
> and dropped a ground plate, drilled thru foundation and ran 6ft
> bare 00 (whatever, thick) back to ground at the panel. Should I
> leave the original connection to the water main???