On 12/28/2020 9:51 PM, Clare Snyder wrote:
On Mon, 28 Dec 2020 16:48:13 -0600, bud-- wrote:
On 12/26/2020 11:17 PM, Clare Snyder wrote:
On Sat, 26 Dec 2020 10:08:22 -0600, bud-- wrote:
On 12/25/2020 6:40 PM, Clare Snyder wrote:
On Fri, 25 Dec 2020 16:38:43 -0500, Ralph Mowery
wrote:
In article ,
lid says...
I can't answer your question but a few months ago I dropped two of those
things off at the local Habitat ReStore. For me, they sucked. There needs
to be a way to use the cord without completely unrolling and removing all
of it. Actually, it wouldn't have been that hard to modify them, but I was
short tempered that day and just wanted to get rid of them.
The way to use them at shorter lengths is to put the middle of the cord
under the hook and wind the cord up on parallel lengths. That way you
have both ends on the outside when you finish. You can then pull out
what you need. It is not good to draw heavy current with the wire
wrapped on the reel as it can over heat. Wire depends on being in open
air for full or near full current capacity.
A plastic reel isn't as bad as a steel one - where the steel acts as
the core of the inductor - - -
The magnetic field of the hot and neutral cancel each other. Otherwise
steel conduit wouldn't be useful.
I agree with Ralph, high current with wire wrapped can overheat the cord.
You are correct with a pure resistive load but with a capacitive or
inductive load (high power factor) if I remeber correctly there is a
reluctance issue
So I guess in Canada you can use ferrous conduit for resistive loads but
not motors, transformers or pf correction capacitors.
(This is not GFCI related.)
Perhaps you could explain?
Canadian physics?
Coriolis effect when you are unlivably far north?
============================
A place where inductance is a problem - US-NEC.
The conductor (GEC)connecting a service ground/neutral system to
grounding electrode(s) may be protected by running through a ferrous
conduit. This is a single conductor and results in unacceptable
inductance and resulting voltage drop. (A earthed surge resulting from
lightning has high frequency components, which are much more
problematic.) The conductor is required to be bonded to the conduit at
each end so the conduit is a parallel conductor, and the conduit carries
a significant part of the current to earth.
I was thinking the leading or lagging power factor would/could cause
a current phase shift between the line and neutral conductor, or
between the 2 lines and neutral of a 240 volt CT supply.
IF there is a phase shift the magnetic feild would be asymetrical and
the asymetry would cause an unballanced inductive effect - with the
unbalance causing an "inductive load" (field) that would be
concentrated by the core. My AC electric theory education goes back
50 years - so I could have made a faulty assumption somewhere down the
line - - - -
For a 120V motor there is a phase shift, but it occurs in both the hot
and neutral. The current in the hot and neutral has to be be the same
(at any instant the sum of the currents has to be zero). "What goes in
must come out."
If you had a 3-phase 4-wire set to a 'load', the phase shifts on the
individual wires could all be different, but again the sum of the
currents at any instant must be zero.