This is a theoretical electrical question, not something I actually
plan to do. Say somebody wants to run a new circuit from the breaker
box to one special outlet, like for a microwave oven or window air
conditioner or something like that. Being an ecconomical sort, this
guy decides that instead of buying the proper gauge wire for the job,
he'll use up some 14 gauge wire which is lying around from a previous
job, but run two hot lines and two ground lines in parallel, as
diagrammed below.

Box: Hot ====================
                                                       Load Outlet
Box: Ground==================

So we have two black 14g wires running from the hot connector on the
breaker to the outlet and two white 14g wires running back from the
outlet to the ground in the box. Two questions:

1. What gauge single wire would this be equivalent to in current
carrying capacity? That is, would this be the same as running a single
10g or 8g or what? Maybe 14g / 2 = 7g?

2. This seems to be very unsafe but I'm not sure why. It's probably
against every wiring code everywhere. What's the danger with this set
up?

Again, I'm not going to do this, I'm actually going to go out and buy
the proper gauge wire for my project, but this popped into my head and
I wondered what the rest of you thought about it.

Paul

On Jun 22, 9:18=A0am, Pavel314  wrote:
> This is a theoretical electrical question, not something I actually
> plan to do. Say somebody wants to run a new circuit from the breaker
> box to one special outlet, like for a microwave oven or window air
> conditioner or something like that. Being an ecconomical sort, this
> guy decides that instead of buying the proper gauge wire for the job,
> he'll use up some 14 gauge wire which is lying around from a previous
> job, but run two hot lines and two ground lines in parallel, as
> diagrammed below.
>
> Box: Hot =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0Load Outlet
> Box: Ground=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>
> So we have two black 14g wires running from the hot connector on the
> breaker to the outlet and two white 14g wires running back from the
> outlet to the ground in the box. Two questions:
>
> 1. What gauge single wire would this be equivalent to in current
> carrying capacity? That is, would this be the same as running a single
> 10g or 8g or what? Maybe 14g / 2 =3D 7g?
>
> 2. This seems to be very unsafe but I'm not sure why. It's probably
> against every wiring code everywhere. What's the danger with this set
> up?
>
> Again, I'm not going to do this, I'm actually going to go out and buy
> the proper gauge wire for my project, but this popped into my head and
> I wondered what the rest of you thought about it.
>
> Paul

The danger would be that one half of the circuit could fail and the
remaining half would be overloaded.

In your example it's probably ok to run a microwave on a 15amp circuit
with a single piece of 14/2.  But I would run 12/2 on a 20 amp
myself.  A dryer would be a better example.

Pavel314 wrote:
> This is a theoretical electrical question, not something I actually
> plan to do. Say somebody wants to run a new circuit from the breaker
> box to one special outlet, like for a microwave oven or window air
> conditioner or something like that. Being an ecconomical sort, this
> guy decides that instead of buying the proper gauge wire for the job,
> he'll use up some 14 gauge wire which is lying around from a previous
> job, but run two hot lines and two ground lines in parallel, as
> diagrammed below.
> 
> Box: Hot ====================
>                                                        Load Outlet
> Box: Ground==================
> 
> So we have two black 14g wires running from the hot connector on the
> breaker to the outlet and two white 14g wires running back from the
> outlet to the ground in the box. Two questions:
> 
> 1. What gauge single wire would this be equivalent to in current
> carrying capacity? That is, would this be the same as running a single
> 10g or 8g or what? Maybe 14g / 2 = 7g?

You _could_ look up the wire size tables, but -- two 14's are the area 
of between one 12 and one 10.  A14 = 0.003, A12 = 0.005, A10 = 0.008

> 2. This seems to be very unsafe but I'm not sure why. It's probably
> against every wiring code everywhere. What's the danger with this set
> up?

The prime danger is one of the loss of connection or disparity in the 
quality of connection to one of the two conductors as most terminals are 
not designed for more than one wire under the connector.

It would be possible to do so by pigtailing ends to a third conductor 
for the connection.

AFAIK the arrangement is not condoned by NEC; where specifically it says 
it except under the workmanship clause I've no idea since it's patently 
silly as two wires of smaller size are more costly than the one larger.

But, if the ends were stranded, functionally there would really be no 
difference between the it and stranded wire of equivalent area.


> Again, I'm not going to do this, I'm actually going to go out and buy
> the proper gauge wire for my project, but this popped into my head and
> I wondered what the rest of you thought about it.


As above, it's not "the right way" for the safety issue in the 
connections, mostly which is at least one reason for it not being 
Code-acceptable.

--

Pavel314 wrote:
> This is a theoretical electrical question, not something I actually
> plan to do. Say somebody wants to run a new circuit from the breaker
> box to one special outlet, like for a microwave oven or window air
> conditioner or something like that. Being an ecconomical sort, this
> guy decides that instead of buying the proper gauge wire for the job,
> he'll use up some 14 gauge wire which is lying around from a previous
> job, but run two hot lines and two ground lines in parallel, as
> diagrammed below.
>
> Box: Hot ====================
>                                                         Load Outlet
> Box: Ground==================
>
> So we have two black 14g wires running from the hot connector on the
> breaker to the outlet and two white 14g wires running back from the
> outlet to the ground in the box. Two questions:
>
> 1. What gauge single wire would this be equivalent to in current
> carrying capacity? That is, would this be the same as running a single
> 10g or 8g or what? Maybe 14g / 2 = 7g?
>
> 2. This seems to be very unsafe but I'm not sure why. It's probably
> against every wiring code everywhere. What's the danger with this set
> up?
>
> Again, I'm not going to do this, I'm actually going to go out and buy
> the proper gauge wire for my project, but this popped into my head and
> I wondered what the rest of you thought about it.
>
> Paul
Hi,
Since you mention theory, if you make the length of wires EXACTLY same 
to even the load current and make sure two wires always stay connected 
TOGETHER, it'll be OK.

On Jun 22, 9:51=A0am, Tony Hwang  wrote:
> Pavel314 wrote:
> > This is a theoretical electrical question, not something I actually
> > plan to do. Say somebody wants to run a new circuit from the breaker
> > box to one special outlet, like for a microwave oven or window air
> > conditioner or something like that. Being an ecconomical sort, this
> > guy decides that instead of buying the proper gauge wire for the job,
> > he'll use up some 14 gauge wire which is lying around from a previous
> > job, but run two hot lines and two ground lines in parallel, as
> > diagrammed below.
>
> > Box: Hot =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0=
 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 Load Outlet
> > Box: Ground=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>
> > So we have two black 14g wires running from the hot connector on the
> > breaker to the outlet and two white 14g wires running back from the
> > outlet to the ground in the box. Two questions:
>
> > 1. What gauge single wire would this be equivalent to in current
> > carrying capacity? That is, would this be the same as running a single
> > 10g or 8g or what? Maybe 14g / 2 =3D 7g?
>
> > 2. This seems to be very unsafe but I'm not sure why. It's probably
> > against every wiring code everywhere. What's the danger with this set
> > up?
>
> > Again, I'm not going to do this, I'm actually going to go out and buy
> > the proper gauge wire for my project, but this popped into my head and
> > I wondered what the rest of you thought about it.
>
> > Paul
>
> Hi,
> Since you mention theory, if you make the length of wires EXACTLY same
> to even the load current and make sure two wires always stay connected
> TOGETHER, it'll be OK.- Hide quoted text -
>
> - Show quoted text -

I think you're both wrong.  A single lead failure results in an
overload on the remaining lead.  And I think this is banned by the
code which would require that a conductor connected to a breaker be
rated to carry the load of the breaker.  In otherwords an inspector
would fail me for connecting 14/2 to a 30amp breaker.  Even though two
pieces of 14/2 could carry 30 amps.

jamesgangnc wrote:
> On Jun 22, 9:51 am, Tony Hwang  wrote:
>> Pavel314 wrote:
>>> This is a theoretical electrical question, not something I actually
>>> plan to do. Say somebody wants to run a new circuit from the breaker
>>> box to one special outlet, like for a microwave oven or window air
>>> conditioner or something like that. Being an ecconomical sort, this
>>> guy decides that instead of buying the proper gauge wire for the job,
>>> he'll use up some 14 gauge wire which is lying around from a previous
>>> job, but run two hot lines and two ground lines in parallel, as
>>> diagrammed below.
>>
>>> Box: Hot ====================
>>>                                                          Load Outlet
>>> Box: Ground==================
>>
>>> So we have two black 14g wires running from the hot connector on the
>>> breaker to the outlet and two white 14g wires running back from the
>>> outlet to the ground in the box. Two questions:
>>
>>> 1. What gauge single wire would this be equivalent to in current
>>> carrying capacity? That is, would this be the same as running a single
>>> 10g or 8g or what? Maybe 14g / 2 = 7g?
>>
>>> 2. This seems to be very unsafe but I'm not sure why. It's probably
>>> against every wiring code everywhere. What's the danger with this set
>>> up?
>>
>>> Again, I'm not going to do this, I'm actually going to go out and buy
>>> the proper gauge wire for my project, but this popped into my head and
>>> I wondered what the rest of you thought about it.
>>
>>> Paul
>>
>> Hi,
>> Since you mention theory, if you make the length of wires EXACTLY same
>> to even the load current and make sure two wires always stay connected
>> TOGETHER, it'll be OK.- Hide quoted text -
>>
>> - Show quoted text -
>
> I think you're both wrong.  A single lead failure results in an
> overload on the remaining lead.  And I think this is banned by the
> code which would require that a conductor connected to a breaker be
> rated to carry the load of the breaker.  In otherwords an inspector
> would fail me for connecting 14/2 to a 30amp breaker.  Even though two
> pieces of 14/2 could carry 30 amps.
Hi,
I said it based on theory not on real life practice.
OP mentioned theory.

On Tue, 22 Jun 2010 06:18:54 -0700, Pavel314 wrote:

> This is a theoretical electrical question, not something I actually plan
> to do. Say somebody wants to run a new circuit from the breaker box to
> one special outlet, like for a microwave oven or window air conditioner
> or something like that. Being an ecconomical sort, this guy decides that
> instead of buying the proper gauge wire for the job, he'll use up some
> 14 gauge wire which is lying around from a previous job, but run two hot
> lines and two ground lines in parallel, as diagrammed below.

That's essentially the way it's done in the UK; wiring is run such that 
outlets sit on a ring circuit rather than a radial from the service panel 
(consumer unit in UK parlance). See:

  http://en.wikipedia.org/wiki/Ring_circuit

I'm sure it violates all sorts of rules this side of the Pond :-)

cheers

Jules

On Jun 22, 10:21=A0am, Tony Hwang  wrote:
> jamesgangnc wrote:
> > On Jun 22, 9:51 am, Tony Hwang =A0wrote:
> >> Pavel314 wrote:
> >>> This is a theoretical electrical question, not something I actually
> >>> plan to do. Say somebody wants to run a new circuit from the breaker
> >>> box to one special outlet, like for a microwave oven or window air
> >>> conditioner or something like that. Being an ecconomical sort, this
> >>> guy decides that instead of buying the proper gauge wire for the job,
> >>> he'll use up some 14 gauge wire which is lying around from a previous
> >>> job, but run two hot lines and two ground lines in parallel, as
> >>> diagrammed below.
>
> >>> Box: Hot =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> >>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0Load Outlet
> >>> Box: Ground=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>
> >>> So we have two black 14g wires running from the hot connector on the
> >>> breaker to the outlet and two white 14g wires running back from the
> >>> outlet to the ground in the box. Two questions:
>
> >>> 1. What gauge single wire would this be equivalent to in current
> >>> carrying capacity? That is, would this be the same as running a singl=
e
> >>> 10g or 8g or what? Maybe 14g / 2 =3D 7g?
>
> >>> 2. This seems to be very unsafe but I'm not sure why. It's probably
> >>> against every wiring code everywhere. What's the danger with this set
> >>> up?
>
> >>> Again, I'm not going to do this, I'm actually going to go out and buy
> >>> the proper gauge wire for my project, but this popped into my head an=
d
> >>> I wondered what the rest of you thought about it.
>
> >>> Paul
>
> >> Hi,
> >> Since you mention theory, if you make the length of wires EXACTLY same
> >> to even the load current and make sure two wires always stay connected
> >> TOGETHER, it'll be OK.- Hide quoted text -
>
> >> - Show quoted text -
>
> > I think you're both wrong. =A0A single lead failure results in an
> > overload on the remaining lead. =A0And I think this is banned by the
> > code which would require that a conductor connected to a breaker be
> > rated to carry the load of the breaker. =A0In otherwords an inspector
> > would fail me for connecting 14/2 to a 30amp breaker. =A0Even though tw=
o
> > pieces of 14/2 could carry 30 amps.
>
> Hi,
> I said it based on theory not on real life practice.
> OP mentioned theory.- Hide quoted text -
>
> - Show quoted text -

Even in the theoretical world it would still be bad because of the
potential for a single lead failure.  Safety aside you would also end
up with reduced voltage at the load in the event of a single lead
failure.  In the case of a load like an AC this could lead to
compressor failure.

jamesgangnc wrote:
> On Jun 22, 10:21 am, Tony Hwang  wrote:
>> jamesgangnc wrote:
>>> On Jun 22, 9:51 am, Tony Hwang    wrote:
>>>> Pavel314 wrote:
>>>>> This is a theoretical electrical question, not something I actually
>>>>> plan to do. Say somebody wants to run a new circuit from the breaker
>>>>> box to one special outlet, like for a microwave oven or window air
>>>>> conditioner or something like that. Being an ecconomical sort, this
>>>>> guy decides that instead of buying the proper gauge wire for the job,
>>>>> he'll use up some 14 gauge wire which is lying around from a previous
>>>>> job, but run two hot lines and two ground lines in parallel, as
>>>>> diagrammed below.
>>
>>>>> Box: Hot ====================
>>>>>                                                           Load Outlet
>>>>> Box: Ground==================
>>
>>>>> So we have two black 14g wires running from the hot connector on the
>>>>> breaker to the outlet and two white 14g wires running back from the
>>>>> outlet to the ground in the box. Two questions:
>>
>>>>> 1. What gauge single wire would this be equivalent to in current
>>>>> carrying capacity? That is, would this be the same as running a single
>>>>> 10g or 8g or what? Maybe 14g / 2 = 7g?
>>
>>>>> 2. This seems to be very unsafe but I'm not sure why. It's probably
>>>>> against every wiring code everywhere. What's the danger with this set
>>>>> up?
>>
>>>>> Again, I'm not going to do this, I'm actually going to go out and buy
>>>>> the proper gauge wire for my project, but this popped into my head and
>>>>> I wondered what the rest of you thought about it.
>>
>>>>> Paul
>>
>>>> Hi,
>>>> Since you mention theory, if you make the length of wires EXACTLY same
>>>> to even the load current and make sure two wires always stay connected
>>>> TOGETHER, it'll be OK.- Hide quoted text -
>>
>>>> - Show quoted text -
>>
>>> I think you're both wrong.  A single lead failure results in an
>>> overload on the remaining lead.  And I think this is banned by the
>>> code which would require that a conductor connected to a breaker be
>>> rated to carry the load of the breaker.  In otherwords an inspector
>>> would fail me for connecting 14/2 to a 30amp breaker.  Even though two
>>> pieces of 14/2 could carry 30 amps.
>>
>> Hi,
>> I said it based on theory not on real life practice.
>> OP mentioned theory.- Hide quoted text -
>>
>> - Show quoted text -
>
> Even in the theoretical world it would still be bad because of the
> potential for a single lead failure.  Safety aside you would also end
> up with reduced voltage at the load in the event of a single lead
> failure.  In the case of a load like an AC this could lead to
> compressor failure.
Hmm,
What is the definition of theory?

In article <4...@x21g2000yqa.googlegroups.com>, Pavel314 <p...@jhmi.edu> wrote:
>This is a theoretical electrical question, not something I actually
>plan to do. Say somebody wants to run a new circuit from the breaker
>box to one special outlet, like for a microwave oven or window air
>conditioner or something like that. Being an ecconomical sort, this
>guy decides that instead of buying the proper gauge wire for the job,
>he'll use up some 14 gauge wire which is lying around from a previous
>job, but run two hot lines and two ground lines

Hold it right there, cowboy.

If you don't know the difference between neutral and ground, you have no 
business mucking about with 120VAC.

> in parallel, as
>diagrammed below.

Code violation. Conductors are not allowed to be run in parallel below a 
certain size -- I think 2/0, but I'm not sure without looking it up.