So the ice storm the othe day took down many trees in our area. My
BIL called me because a branch fell and knocked his neutral wire
loose
from the weatherhead. Some things worked others didn't, biggest
problem was when the fridge kicked on the whole house went dim.

I asked him about a ground rod and he was sure he didn't have one.
Until he could get a guy to climb up there I told him to go get a
ground rod at the Borg and pound it in as far as he could and connect
it to the ground/neutral bar in his panel. He was able to get the
ground rod about 5' down with a hammer and connected two 12ga copper
wires from the rod to his panel. After he did this there was no
improvement at all.

An hour later an electrician he knows showed up and reconnected the
neutral to the weaterhead and all was better. Neither of his hot
leads at the weatherhead were loose or needed to be touched. So why
wouldn't going directly to ground from the panel have helped his
problem?

*As someone else said the ground rod is not a substitute for a neutral.
Neutral current wants to return to the power company transformer. To
get
there it normally travels over the neutral (Grounded conductor) wire.
When
the neutral wire is broken, but is bonded to the grounding conductor in
the
main panel, the neutral current will attempt to get to the transformer
via
the grounding conductor. However whether it makes it back to the
transformer or not depends on the conditions. The transformer must have
an
unbroken grounding conductor connected to a ground rod in order for the
neutral current to travel through the earth. There should also be a
path
of
low resistance and that would depend on the soil conditions and
distance.

I have heard stories from other contractors and inspectors of the
neutral
current from one house traveling through the earth to a neighbor's
grounding
conductor and going back to the transformer via the neighbor's neutral
wire.

I hope that your BIL turned off the main breaker when he attempted to
connect the ground rod. All of the return current could have been on
that
grounding conductor.

Yes, he turned off the main and all of the individual breakers before
trying this. Turned the main back on then each breaker.


BTW the advice that you gave your BIL could have been fatal not only to
him,
but to someone who just happened to be walking on his lawn at that
time.
Also, If there was a pool nearby, although not likely this time of year
someone in the pool could have gotten zapped from the stray current in
the
earth looking for a path to the transformer. He could also have damaged
some appliances by having a higher voltage than normal passing through
them
The best advice in this case would have been to shut off the main
breaker
and get the neutral wire reconnected.

How could someone walking by have been shocked? Doesn't electricity
always seek ground?

BTW he also got the same advice from another guy who works at the
power company. Obviously not as a permanent fix but to get his heat
working til he could get the neutral wire reconnected.

So in my house as with most houses even though all of the neutrals and
grounds are tied together in the panel everything is going back to the
transformer?

*Lightning goes to earth, neutral current goes back to the transformer.
If
everything is grounded and bonded to code and all connections are tight,
all
neutral current should travel back to the transformer via the neutral
conductor. You can put an ammeter on the grounding conductor to see if
any
current is flowing. Unfortunately the meter won't tell you what
direction
it is flowing. If your neighbor lost his or her neutral connection you
could have their neutral current flowing up into your panel and back to
the
transformer via your neutral conductor. This can be confirmed by
shutting
off your main breaker to see if the current flow stops. If it doesn't,
talk
to your neighbors.

I come in contact with a number of power company workers every year. I
am
always surprised at the questions some of them ask me about wiring in
their
own house. This past summer I had a guy ask me how he could do a service
upgrade at his mother's house. The perception is that since they work
for
the power company, they know all about electricity. The fact is that
they
are very good at what the company trains them to do, but that does not
include wiring a house or making a service change because the power
company
normally doesn't do that type of work.

The reference standards used for power distribution (NESC) and for
residential and commercial wiring (NEC) are quite different. Utility
personnel will be familiar with the NESC standards, but usually aren't
familiar with the NEC standards to much extent.


*Thanks for that clarification Pete. I am familiar with the NEC but know
absolutely nothing about the NESC.