240 Volt wire?
 

Hi,

I have a wire that seems to have only to conductors in it. It's a gray
wire in which the plastic sheath is tight over the wire. The two wires
are about 1/4" apart. I'm not sure how to better describe it.

It seems to be connected to a double breaker and carrying 240V to the
A/C unit. Does that make sense? I guess if the two wires are 120V
out-of-phase then the AC current can just flow from one of the wires to
the other?

I'm trying to make sense of this for my own education, but also
wondering what kind of wire I would need (12/2?) to replace this one
(it's routed stupidly).

Thanks,

Aaron

240 Volt wire?
 

How many amps, the breaker? For 20 amps, use 12 ga, for 30
amps, use 10 ga.

I've seen 2 conductor (with ground) wire used. I've also
seen 3 conductor used, so there is a neutral as well as a
ground.

Yes, the two poles of the 220 volt are out of time with each
other. Oddly, they call that single phase 220.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Aaron Fude" wrote in message
...
Hi,

I have a wire that seems to have only to conductors in it.
It's a gray
wire in which the plastic sheath is tight over the wire. The
two wires
are about 1/4" apart. I'm not sure how to better describe
it.

It seems to be connected to a double breaker and carrying
240V to the
A/C unit. Does that make sense? I guess if the two wires are
120V
out-of-phase then the AC current can just flow from one of
the wires to
the other?

I'm trying to make sense of this for my own education, but
also
wondering what kind of wire I would need (12/2?) to replace
this one
(it's routed stupidly).

Thanks,

Aaron

240 Volt wire?
 

On Jul 30, 10:54*am, Aaron Fude wrote:
Hi,

I have a wire that seems to have only to conductors in it. It's a gray
wire in which the plastic sheath is tight over the wire. The two wires
are about 1/4" apart. I'm not sure how to better describe it.

It seems to be connected to a double breaker and carrying 240V to the
A/C unit. Does that make sense? I guess if the two wires are 120V
out-of-phase then the AC current can just flow from one of the wires to
the other?

I'm trying to make sense of this for my own education, but also
wondering what kind of wire I would need (12/2?) to replace this one
(it's routed stupidly).

Thanks,

Aaron.

As posted: The question begs some very basic information.

Do hope that what is is described is not some sort of lash-up, perhaps
using some sort of lamp wiring or portable extension cord????? In
which case it a) May not be safe b) Not of sufficient size c) Not meet
insurance standards (Liability?) or electrical codes.

1) The size of wire depends on the load to be carried.
In North America typical a
#14 AWG 15 amps. Typically used for lighting circuits.
#12 AWG 20 amps. Often/sometimes for duplex wall outlets etc.
#10 AWG 30 amps. Typically for a clothes dryer and/or electric hot
water tank circuit.
Most wires (if they meet code) are rated for either 300 or 600
volts.
Wiring may have either two insulated conductors plus ground wire.
2) The circuit breaker must be sized to the gauge of wire.
As per above wire rating; do not exceed. The circuit breaker protects
the wiring and anything connected to that circuit.
For example do not connect say 14 AWG to a 20 amp breaker.
And/or do not 'extend', say, an existing #12 AWG circuit using a
lesser (higher numbered) gauge wire such as #14.
3) A typical continuous maximum load is 80% of the rated capacity. So,
for example a 20 amp circuit is normally happy carrying some 15 to 16
amps.
Regarding 220 versus 110 (sometimes it's 230 and 115 and sometimes
again it's 240 vs. 120) but the principal, in domestic situations, but
not industrial or commercial applications where there may be 208 volts/
347 volts etc. is the same.
Have emailed the OP directly with a suggestion as to how to recognise
a domestic SINGLE PHASE 110/220 volt service.

240 Volt wire?
 

Stormin Mormon wrote:
How many amps, the breaker? For 20 amps, use 12 ga, for 30
amps, use 10 ga.

I've seen 2 conductor (with ground) wire used. I've also
seen 3 conductor used, so there is a neutral as well as a
ground.

Yes, the two poles of the 220 volt are out of time with each
other. Oddly, they call that single phase 220.

Well, they call it single phase because it is -- it's derived from two
taps from the same generation phase that are (as you say) lagged 180
degrees with respect to each other.

IOW, while the two are "out of phase" w/ each other, they are not
delivered from separate wires from the generator only two different
voltage taps. As an aside, three phase is separated by 120 degrees on
each phase so the difference in voltage between any two of them is
variable in time where as the two in single-phase 240V are mirror images
of each other and the voltage magnitude is fixed w/ time (sin^2 + cos^2
= constant).

Potentially (so to speak :) ) cornfoozing as there are two uses of the
word "phase", both of which are correct but refer to different
quantities/properties--the generator phases and the phase shift between
any two or three legs of the single- or three-phase power.

--

240 Volt wire?
 

On Jul 30, 10:45 am, dpb wrote:
...where as the two in single-phase 240V are mirror images
of each other

Correct.

and the voltage magnitude is fixed w/ time (sin^2 + cos^2
= constant).

Ummm... Not unless your two hot wires are 90 degrees out of phase and
you're using 2 dimensional wire. The voltage magnitude is 2*v*sin(t).
3 phase is more interesting (something like v*sin(t)-v*sin(t+120deg)).

Maybe you're remembering some current X magnetic field vector from a
previous life?

240 Volt wire?
 

On Jul 30, 8:54*am, Aaron Fude wrote:
Hi,

I have a wire that seems to have only to conductors in it. It's a gray
wire in which the plastic sheath is tight over the wire. The two wires
are about 1/4" apart. I'm not sure how to better describe it.

It seems to be connected to a double breaker and carrying 240V to the
A/C unit. Does that make sense? I guess if the two wires are 120V
out-of-phase then the AC current can just flow from one of the wires to
the other?

I'm trying to make sense of this for my own education, but also
wondering what kind of wire I would need (12/2?) to replace this one
(it's routed stupidly).

Thanks,

Aaron

I would look again to make sure there is not a ground in there. Is
this an external ac compressor? Many ac's use only 240 and only need
2 hots and a ground. I've never seen one that didn't call for a
ground though. You can replace it with the appropriate guage 12/2 or
10/2 with ground. It's ok if one wire is white and the other black.
Some electricians will wrap a piece of black tape on the white wire
near the ends so that it is obvious it is a also a hot. If the ground
is missing then you should correct that situation. If you can not
tell what size it is then locate the amperage on a tag on the ac and
estimate the run length. Lots of resources on the net will calculate
the correct wire size for you. If it is routed stupidly will you have
enough wire to change the route if you just disconnect one end and re-
route it?

240 Volt wire?
 

"Aaron Fude" wrote in message
...
Hi,

I have a wire that seems to have only to conductors in it. It's a gray
wire in which the plastic sheath is tight over the wire. The two wires are
about 1/4" apart. I'm not sure how to better describe it.

It seems to be connected to a double breaker and carrying 240V to the A/C
unit. Does that make sense? I guess if the two wires are 120V out-of-phase
then the AC current can just flow from one of the wires to the other?

I'm trying to make sense of this for my own education, but also wondering
what kind of wire I would need (12/2?) to replace this one (it's routed
stupidly).

Thanks,

Aaron

Is there a ground wire at all? I know UF cable is gray (well the sheathing
is). Example:

http://electrical.hardwarestore.com/...667888.aspxYou have to look at the breaker that it is hooked up too. Some units onlyrequire a 30 amp breaker in which case you would use 10/2 with ground or10/3 with ground if for some reason you need the neutral. If you are goingto replace it, then maybe think about setting a disconnect like this:http://www.lowes.com/lowes/lkn?actio...&lpage=noneand get one of these and use #10 thhn wire inside to go from the box to theAC unit (look at the picture on the bag):http://www.lowes.com/lowes/lkn?actio...B&lpage=noneOf course this is just an example for a 30 Amp system.

240 Volt wire?
 

"gore" wrote in message
...

"Aaron Fude" wrote in message
...
Hi,

I have a wire that seems to have only to conductors in it. It's a gray
wire in which the plastic sheath is tight over the wire. The two wires
are about 1/4" apart. I'm not sure how to better describe it.

It seems to be connected to a double breaker and carrying 240V to the A/C
unit. Does that make sense? I guess if the two wires are 120V
out-of-phase then the AC current can just flow from one of the wires to
the other?

I'm trying to make sense of this for my own education, but also wondering
what kind of wire I would need (12/2?) to replace this one (it's routed
stupidly).

Thanks,

Aaron

Is there a ground wire at all? I know UF cable is gray (well the sheathing
is). Example:


http://electrical.hardwarestore.com/...e--667888.aspx

You have to look at the breaker that it is hooked up too. Some units
onlyrequire a 30 amp breaker in which case you would use 10/2 with ground
or10/3 with ground if for some reason you need the neutral. If you are
goingto replace it, then maybe think about setting a disconnect like this:

http://www.lowes.com/lowes/lkn?actio...1RP&lpage=none .

and get one of these and use #10 thhn wire inside to go from the box to
theAC unit (look at the picture on the bag): .

http://www.lowes.com/lowes/lkn?actio...DRB&lpage=none .

Of course this is just an example for a 30 Amp system.

sorry about the links usually it works. anyway I would get a 30A disconnect,
some THHN #10, and some Carflex and connectors for the outside.

240 Volt wire?
 

Larry The Snake Guy wrote:
On Jul 30, 10:45 am, dpb wrote:
...where as the two in single-phase 240V are mirror images
of each other

Correct.

and the voltage magnitude is fixed w/ time (sin^2 + cos^2
= constant).

Ummm... Not unless your two hot wires are 90 degrees out of phase and
you're using 2 dimensional wire. The voltage magnitude is 2*v*sin(t).
3 phase is more interesting (something like v*sin(t)-v*sin(t+120deg)).

Maybe you're remembering some current X magnetic field vector from a
previous life?

No, just an unfortunate ill-considered (or, more correctly, really not
at all considered) attempt at a mixed metaphor...which while true
geometrically, has nothing to do w/ the voltage... :(

Thanks for bringing it to everybody's attention... :) (Not that
shouldn't have corrected the factual blooper)

--

240 Volt wire?
 

"Aaron Fude" wrote in message
...
Hi,

I have a wire that seems to have only to conductors in it. It's a gray
wire in which the plastic sheath is tight over the wire. The two wires are
about 1/4" apart. I'm not sure how to better describe it.

It seems to be connected to a double breaker and carrying 240V to the A/C
unit. Does that make sense? I guess if the two wires are 120V out-of-phase
then the AC current can just flow from one of the wires to the other?

I'm trying to make sense of this for my own education, but also wondering
what kind of wire I would need (12/2?) to replace this one (it's routed
stupidly).

Thanks,

Aaron

Aaron, you need to do a tad more investigating before asking questions. Your
description sounds like U.F. cable, but if you look at the jacket, it will
have it's type and size either printed or embossed on it.

240 Volt wire?
 

dpb wrote:

Stormin Mormon wrote:
How many amps, the breaker? For 20 amps, use 12 ga, for 30
amps, use 10 ga.

I've seen 2 conductor (with ground) wire used. I've also
seen 3 conductor used, so there is a neutral as well as a
ground.

Yes, the two poles of the 220 volt are out of time with each
other. Oddly, they call that single phase 220.

Well, they call it single phase because it is -- it's derived from two
taps from the same generation phase that are (as you say) lagged 180
degrees with respect to each other.

IOW, while the two are "out of phase" w/ each other, they are not
delivered from separate wires from the generator only two different
voltage taps. As an aside, three phase is separated by 120 degrees on
each phase so the difference in voltage between any two of them is
variable in time where as the two in single-phase 240V are mirror images
of each other and the voltage magnitude is fixed w/ time (sin^2 + cos^2
= constant).

Potentially (so to speak :) ) cornfoozing as there are two uses of the
word "phase", both of which are correct but refer to different
quantities/properties--the generator phases and the phase shift between
any two or three legs of the single- or three-phase power.

--

The two lines are indeed in phase with each other. They also are not
derived from different voltage taps, they are the connections to the
full 240V winding on the distribution transformer, the "neutral" is a
center tap in those windings. When looking at them relative to the
center tap neutral they will appear to be opposite polarity or 180 out
of phase.