[RE-wrenches] 90 degree wire bends

[Ray Walters]

It seems that if the strands were stretched and therefore thinned, that 
that would increase resistance, some. I think more importantly, the 
insulation  bunchs up and cracks, and is definitely compromised.  Also 
with strain hardening of copper, I'm sure some strands could break 
internally with a tight enough bend. I've heard at least for bare ground 
wires that lightning will jump off to the case at tight bends, but I've 
never actually seen that.
Aside from all that, is there actually an increased impedance from a 
tight bend (like in plumbing)? I don't know.
I've had to stop more than one journeyman from violating 300.34. I just 
tell them the bends should look like the long sweeps in conduit relative 
to the diameter of the wire: also purdy.

Aloha,

Ray

On 11/16/2011 10:35 AM, Marco Mangelsdorf wrote:
>
> Some electricians have great fun in making 90 degree wire bends to try 
> and make their enclosure wiring look so purdy.
>
> Given the importance of maintaining wiring radiuses, this can't be a 
> good idea, can it?  Is the issue greater resistance when the wire is 
> bent at a straight 90 degrees (or more)?
>
> Thanks,
>
> marco
>
>
>
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