Date: Fri, 12 Sep 2014 19:06:38 -0700
From: Jim Brown <jim@audiosystemsgroup.com>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Challenging Grounding/Bonding Situation ?
On Fri,9/12/2014 6:50 PM, Gary Schafer wrote:
> If you have only a 3 wire feed system from your house to garage then you
> have to have that feed neutral wire bonded to the panel at both the house
> and at the garage. If you do not have it bonded to the panel at the garage
> then there is no path for a breaker to trip if there should be a fault of
> hot to ground on any appliance like Bill described.
How many times must I say it? Neutral MUST BE bonded in both buildings
if ground is not carried. They are treated as separate premises.
73, Jim K9YC
## If you have sub fed your 2nd building with only 3 wires, you have done it
wrong. You require 4 conductors. The neutral is NOT bonded to ground in the
sub panel. Neutral only gets grounded in the main panel. Then all fault
current travels
through the ground wire between buildings. Pole pig CT is not only the
neutral, its also grounded to the base of the utility pole. It is also bonded
to the
messenger wire between poles..... ( which is also what the telcos and cable
companies
hang their cables from. That messenger wire is the return for the 12.5 to 14
kv HV
primary. Since the messenger is grounded, it implies that the HV primary is an
unbalanced
system.
## I use 3 x 8 ft rods, all cadweled at base of tower...and 1 more outside
the basement,
45 ft away. 2 ga bare cu is run between the base of tower and 45 ft away to
basement,
then to SPG. Coax braid is bonded to top of towe,r and also bottom of tower..
Bottom
of tower, the coax braid is bonded to ground .via a HOFFI lightning arrestor.
The arrestor
serves as the junction between the LMR-1200DB from the shack... and the more
flexible
cable going up the tower. IF you really want to do it right, the coax should
go up the
inside of the tower, which is not always feasible. Grnd from 200A main panel
in my home
is also bonded to SPG... 20 feet away.
## The .75 inch main water line split a few years back....and replaced with 1
inch od pex pipe.
Pex pipe is abs plastic stuff. So the oem ground is rendered useless. Watch
out driving in 8
ft rods outside a home...you don’t want to get em tangled up with any drain
tiles around the
perimeter of your home.
## I don’t know why hams have so much problems with grounds, power
distribution, lightning induced
fubar etc, etc. The telco I worked for..including main offices, hundreds of
cell sites, dozens of microwave sites
etc, never had issues. You don’t see your local AM and FM broadcast station
disconnecting coax
during a lightning storm do you. They all survive with multiple hits every
year.
## The one thing the local electrical inspector frowned upon..and read the
contractor the riot act..
was using insulated ground wire inside conduit... big no-no.... it was 1 ga,
RW-90.
The conduit looks like a high Z to any lightning apparently. This is one case
where a new stand by generator
was installed at a cell site. Bare wire inside conduit is ok. but not
insulated. Now IF the insulated
grnd wire was bonded to both ends of the conduit.... dunno if they would go for
that or not.
Jim VE7RF
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