I have an outdoor receptacle (B)that is connected to a GFI outdoor
receptacle (A) via a shielded extension cord-14?.B got wet, corrosion set in
and I plan to replace it.I have been told that an outdoor solid wire from A
to B would be better and that if I used a braided wire unless ALL the
strands are securely attached it might conduct but not be able to handle a
heavy load such as an 120 V electric water heater. True? Is there a way I
can measure whether the braided wire is fully conductive
I don't know what a "a shielded extension cord-14" is and how it might
be properly used in this situation.
All else being equal a stranded cable can carry more current than a
single wire of the same gauge. The flow of electricity is primarily around
the outside of a wire and in a stranded cable there is more of that outside
What are you hooking up here? It sounds like the whole plan is wrong
from the start. I sure sounds like you are not following code from the
start. What kind of water heater are you connecting to an extension cord?
Is it a fixed appliance or portable.?
The Litz effect, where more current flows on the perimeter of a wire
than in its core, only really matters at high frequencies; at 60Hz it is
Just take care that all the strands are twisted together and under the
retaining screw. You could solder the strands together to be sure or
put them into a crimped terminal.
The capacity of 14G stranded and solid is identical. But check the
load; if it is a hot water heater 14 might not be nearly big enough.
Joseph Meehan wrote:
If you can't wrap the wire around a screw so that
it is in full contact with all of the strands,
then you should practice a little more or not do
the work. A few stray strands separating at the
cut end are not than uncommon and make no
difference if the screw fully contacts the wire
near the insulated end.
There is no reason not to use solid wire. Stranded is more flexible and
tends to be used for plugs for equipment rather than permanent installs.
The problem with stranded is the connection points. Also it tends to be
bigger to carry the same load as solid core.
Generally speaking, solid wire is used for permanent wiring, and stranded
for power/extension cords (in our code "portable cord"). The sheath is
usually optimized for different conditions.
I can't make enough sense out of your description to know whether you're
talking about the receptacle feed, replacing the extension cord, or what.
It sounds more like permanent wiring. Stranded wire is mostly
irrelevant to house wiring (except inside some light fixtures/dimmers,
and certain methods of using conduit and individual conductors,
etc). For extension cords outdoors - especially long term use, it's
almost always highly advisable to use pre-made extension cords with
molded ends, which are both well connected in the plugs (often by welding)
and vastly more water proof.
It's not a good idea to use solid wire in an "extension cord", because
it'll fatigue/embrittle if exposed to any movement. In cold weather,
most solid wire insulations will crack or shatter, and they
won't stand up to sunlight exposure unless they're specifically
rated for it.
It's virtually impossible to measure how well braided wire makes contact
short of overcurrenting the connection (by several times the ampacity
of the circuit) and seeing if it gets hot. Simply not practical.
Chris Lewis, Una confibula non set est
It\'s not just anyone who gets a Starship Cruiser class named after them.
"heavy load" connected to outdoor GFI receptacle fed from another
outdoor receptacle via zip-cord? Really? Why not put in some proper
wiring, fastened with screw-terminals or anything better than what you
get with a plug/outlet? Wiring suitable for environment.
Most aspects of electrical code have to do with fire prevention, and it
sounds like you're heading the other way.
Are you devising this on your own? I'd suggest you consult a local
electrician for tips.
The main reason one uses braided instead of solid wire is for
flexibility. Solid wire fractures more easily than braided. A great
example of this is CAT5e etc computer network wiring. (The blue stuff)
In the wall they use single copper strands punched onto connectors. Once
it goes from the wall to your computer they use braided wire...
When you terminate a braided wire in a screw connector you can actually
get better contact than a solid wire as it distorts to fill the space
better. A heavier turn on the scredriver would fix that for solid wire
Its the total metal cross sectional area (and type) that determines the
amount of current that can be drawn. You will get a voltage drop in any
wiring that can be defined as a loss of efficency. It does however go
somewhere as radiated heat from the wire itself. Copper is about the
best to use for money outlay. Aluminium and steel have more loss/distance.
A HWS I think is around 1500W. Thats about 13A at 110V or 7A phase to
phase 220V. I'll admit I dont know US wire sizes too well but in
Australia they had 7.5, 10 and 15A leads. 15A was suppose to have a
special plug type. Given the low cost of the wire I'd suggest something
that is rated at 25A min or so, just in case your HWS has dual 1500W
You can measure the voltage drop over the wire when the known load is
on. From that you can calculate resistance/conductivity and thus
efficiency. Ohms law etc. Dont think I'd bother though...
A mild correction :
The correct terminology is solid, stranded, and braided. Each is
different, and each has its application. Cat5e in the wall is
generally solid. Drop cables are stranded (not braided). Braided
is like what women do with hair.
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form firstname.lastname@example.org.
You do see braided conductors on lightning rods. Lightning can be
thought ofd as a high frequency event and the shot flows on the skin
of the wire Braided wire has more skin.
You can also spend a lot of money for "Monster" speaker cable but any
frequency you can hear is wasted on that fancy braided wire.
You can measure the voltage drop between the wire a half inch from the
receptacle, and the screw head that the wire is attached to. I've
never done that but I would expect it to be minuscule, way less than
a volt. Less than a tenth of a volt, I would think.
You don't have to have all the strands under the screw, but you should
have almost all. Is that not possible? With the power off, twist the
strands, and bend the twisted part into a clockwise hook. If a strand
is in contact with the screw head or the part the screw screws into,
or it's anywhere in the sandwich, that's as good as one can do.
In some cases you can solder ring or 2-prong pitchfork ends to the
wire, and put that under the screw. Rings might not work because many
times the screw won't come out all the way. Often home tools,
mixmasterrs, etc. are done that way inside. But I don't think you
need any end at all.
The most likely place, because of the acid in the battery and the
reactions it causes, for a bad connection is between a car's battery
post and the big lead connector on it. If it's *really bad* it will
be hot to the touch.
Remove NOPSAM to email me. Please let
me know if you have posted also.
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