Why would sharp bends do anything? As long as the wire is continuous
the electrons will flow whatever shape the wire is.
I had someone tell me that making sharp bends in romex was bad too.
Thats bullshit. Electricity follows the copper. Bends dont matter.
When I wire something I always like to make it look neat bu bending
the wires around corners and keeping the bends tight to the structure.
you create future fail spots, the bend stresses the metal and has a
good chance of it cracking or similiar in the future. cracked wires
overheat and cause fires
neatness only counts if it doesnt cause troubles.
as for the OP I would run a new ground line thru the clamp at the
copper line, jump out the meter even though it doesnt matter, ideally
the OLD water line could of been left in the ground disconnected at
both ends from water but still used for grounding.......
one thing the OP may find it very hard to drive the ground rods,
standing on ladder with 8 foot rod waving in breeze.
if the ground is hard it might be easier to have a electrician do it
one with proper driver for ground rods
I agree you shouldn't bend it to tight like a
near perfect 90 degrees but you don't need to bend
it that much to get good looks. Bending copper
work harden it and further bending operations can
make it break, but exactly how many bends before
it breaks. When you wrap a 12 gauge wire around a
post, tighten down the screw, and bend the tail to
make it break off, how many bends (back and forth
motions) do you make? For me it is at least four
each way at a very sharp angle. But when you
install romex, you bend it and then how much
additional bending do you do, and how sharp are
the bends compared to a single stripped wire? My
guess is that you would have to do a lot of very
sharp bending to get the wires work hardened
enough to crack.
Perhaps the worry is grounding for a lightning strike. At that kind of power
level, the current can do all sorts of strange things. It might decide to
spark across the gap as well as flowing around the corner.
OT: Bending radius is a significant concern for coaxial cable. Bending the
wire deforms the outer shielding layer away from the desired cylinder. A
sharp bend deforms the cylinder significantly, making one side closer than
the other to the signal-carrying center conductor. This does "funky things"
to the signal. Don't ask me to define that technical term. I'm doing well to
remember my installation training at all. I remember the trainer putting a
meter of some kind on the line and showing how the needle moved when the
cable was bent severely.
When the acceptance testing was done on type NM cable by Underwriters
Laboratories; low these many years ago; the incidents of conductor
insulation damage went up sharply at bend radii of 3 cable diameters.
The US NEC requires bends of five cable diameter in radius as a safety
margin. The problem isn't conductor fracture but rather that the
insulation will fail over time if it is bent too sharply. Since there
is a bare EGC run inside the jacket of type NM cable the possibility of
arcing which can cause a fire is real.
"This alternating current stuff is just a fad. It is much too dangerous
Bends in wires that have low frequency or DC will not have a noticable
effect in most cases. When you get to higher frequencies it will. A
lightning strike is a very steep pulse. It will not follow the bend in the
wire. It may jump off at a bend and go to something else. Also it will
act like an inductor in the wire and in effect you are disconnecting the
wire at the bend.
Sharp bends in wire may or may not be bad as far as the physical routing
You obviously haven't been advised properly. LIGHTNING does not turn
corners well. It will NOT follow the copper if it has sharp bends. The
best way to protect a piece of equipment from lightning is to tie a knot in
the cord. You'll also notice on houses with lightning rods, the cable
coming from them will have nice big easy bends where it comes around the
gutters and down the side. Lightning will blow right out the side of a
conductor that has too tight a bend in it. NOW, back on the topic of the
ground cable in an electrical panel, the tight bends don't matter, because
that ground is not for lighting protection anyway.
"Mike Ryan" < email@example.com> wrote in message
A bend made any sharper than a curve with a radius five times the
diameter of the cable holds the real possibility of breaking the copper
conductor. That is why the code specifies that as the tightest bend
permitted in type NM cable
Well we aren\'t no thin blue heroes and yet we aren\'t no blackguards to.
All wire (and fiber optic cable) has a maximum bending radius. For
romex, wire bend should never exceed what would go around a large fist.
Sharper bends eventually cause insulation breakdown. Install wire to
last 100 years. No sharp bends.
Reasons for no sharp bends for lightning conductors are different.
Others have described symptoms. But the reason involves something
electrical: higher wire impedance. Lightning protection requires a
conductor to be lowest impedance. That means wire length must be
shorter. Sharp bends (like inductors) increase wire impedance. High
current through higher impedance will find other conductive paths -
such as arcing into an adjacent wall.
Problems created by sharp bends and splices are why AC wall
receptacle safety (equipment) grounds do not properly earth lightning;
are not earth grounds.
Two reasons for no sharp bends. Protect wire insulation and high
impedance. Other reasons also exist. Provided are enough reasons to
not bend wire sharply. Too often, defective installations are made by
being too neat. Earthing wire should be short, no sharp bends, and
well separated from other non-earthing wires. Too many want to bundle
that earthing wire with other wires using nylon wrapping straps - to be
neat. That is a worst installation. Better ground wire does not go
over foundation and down to earth. It goes through foundation, not
inside metallic conduit, to make a shorter earthing connection, AND to
be well separated from other wires. That is a 'neater' installation.
Other earthing wires (telephone, cable, satellite dish) use same rules
to met that AC electric earthing wire only where all connect to an
earthing electrode. That is the 'prettier' installation.
Mike Ryan wrote:
Quote from (2000) NEC, Section 334.24:
"Bends in Types NM, NMC, and NMS cable (Romex) shall be made so that
the cable will not be damaged. The radius of the curve of the inner
edge of any bend during or after installation shall not be less than
five times the diameter of the cable."
You need to redo it with a continuous wire, unless you are equipped to
weld (not solder) the wires together. This is generally only done on big
commercial work and is done with exothermic welding gear which you in
all probability don't have.
Assuming this is a residential scenario, the service panel does not
contain high voltage, it contains 240V. Even if it's commercial it isn't
likely above 480V which is still not high voltage.
If you really don't feel safe working in the panel, install your ground
rods and the wire all the way back to the panel leaving plenty of extra
and then have an electrician stop by and make the connection in the
You're not messing with high voltage just changing the ground wire.
Shut off the main breaker, open the box and replace it. It's no
biggie to do. Just do not put your hands or any metal objects near
the large black cables that enter the box (normally on the top). As
long as you stay away from them, and have the main shut off, you are
in no danger just changing a ground wire.
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