On Mar 14, 6:10 pm, "Jimmy" <[email protected]> wrote:
> I have to run a 220v 14amp line about 15 ft. Will a line of 14/2 work or
> will there be a problem with the wire getting too hot? The motor says it
> pulls 11amps.
>
> Thanks
> Jimmy
For most residential wiring applications, NEC says
No. 14 = 15 amps
No. 12 = 20 amps
No. 10 = 30 amps
On Mar 14, 7:42 pm, Lew Hodgett <[email protected]> wrote:
[schnipf]
> chop off the
> ends, and rewire as necessary.
>
..won't the voltages leak out when you cut it?
On Mar 14, 8:38 pm, Unquestionably Confused <[email protected]>
wrote:
>. Probably even duct tape wouldn't hold it back.
Even though duct tape is shiny?
On Mar 14, 9:32 pm, Unquestionably Confused <[email protected]>
wrote:
> Robatoy wrote:
> > On Mar 14, 8:38 pm, Unquestionably Confused <[email protected]>
> > wrote:
>
> >> . Probably even duct tape wouldn't hold it back.
>
> > Even though duct tape is shiny?
>
> No chance. That shiny surface is slick. Less resistance, the little
> volty things will really fly!
Wowsers, that electricality stuff sure is complex.
On Mar 14, 11:03 pm, "Paul Gilbert" <[email protected]> wrote:
> Not to worry about the volts, it's the smoke leaking out that causes
> problems. Poorly wired or insulated wire often leaks smoke which causes a
> myriad of problems.
>
But, but.. isn't that the stuff that browns my toast in the morning?
On Mar 15, 12:03 am, "Robatoy" <[email protected]> wrote:
> On Mar 14, 9:32 pm, Unquestionably Confused <[email protected]>
> wrote:
>
> > Robatoy wrote:
> > > On Mar 14, 8:38 pm, Unquestionably Confused <[email protected]>
> > > wrote:
>
> > >> . Probably even duct tape wouldn't hold it back.
>
> > > Even though duct tape is shiny?
>
> > No chance. That shiny surface is slick. Less resistance, the little
> > volty things will really fly!
>
> Wowsers, that electricality stuff sure is complex.
Sure is. With AC, you're paying for the same electrons to
flow back and forth through your appliances. Edison was
right, alternating current is a ripoff.
On Mar 18, 7:28 am, [email protected] (Ross Hebeisen) wrote:
[snip]
> not only that but they must be gay cause they go both ways
Gays go one way....seldom both, because that would make them bi.
Cheney's daughter wouldn't be caught dead with a man. (Of course she
never had one around her to look up to either.)
On Mar 15, 12:27 am, Lew Hodgett <[email protected]> wrote:
> Toller wrote:
>
> > You must be joking about this.
>
> Why do you say that?
>
> Lew
The OP doesn't exactly specify whether he's running a permanent
circuit or an "extension" cord. For an extension cord, Lew's
suggestion is fine, and even 12AWG would be fine for that distance
(and easier to find). A year or so ago, HF had 25' 12 AWG extention
cords for something like $7. I bought four of them because it was
cheaper than the raw cable price.
For a permanent circuit installation, it would indeed be a joke (and a
code violation) to use cable from a molded cord set.
To the OP:
In ANY case, you must size the wire to the distance, load, and
acceptable voltage drop. In figuring the distance, you must include
the desired extension cord, the lead that's wired into the tool, and
the wiring in the wall all the way back to the breaker panel. If
you're running a permanent circuit, you need to do it according to
code for a 220V 15A circuit (or larger if you want to have overhead
for the future - RECOMMENDED)
>
> Wire is CHEAP by comparison to other thing electrical including the
> cost of electricity.
>
> #14 AWG will handle it legally; however, the line drop introduced by
> using a small wire #14 AWG) will bite you in the ass every month when
> the electricity bill hits your door step because you have to pay for
> all that wasted power caused by using a small wire at high load.
>
> Buy a 10-2 with ground, molded cord set, 25 ft long, chop off the
> ends, and rewire as necessary.
>
> It is the lowest cost solution available, trust me.
>
> Have fun.
>
> Lew
Sorry Lew, but I get suspicious when somebody says "trust me".
Normally, I would let this one slide. After all, the worst that might
happen if he follows your advice is that he might spend an extra few
bucks on wire. But it's a slow day at the office, so I decided to run
some numbers.
1. A 25 ft. 10-3 extension cord costs about $25.00 say $1.00 per
foot.
2. 14-2 w/g Romex costs about $0.27 cents a foot
3. The difference of $0.73 per foot x 15 feet equals a materials cost
difference of $10.95 for the job.
4. #14 wire has a resistance of about 0.00258 ohms per foot
5. #10 wire has a resistance of about 0.00120 ohms per foot
6. 0.00138 ohms difference x 30 foot total run equals 0.0414 ohms
difference in resistance between the two proposed types of wire.
7. The power lost in a wire equals the current (squared) x
resistance. At 11 amps load, the difference in power lost is 0.0414 x
11(squared) equals 5.01 watts.
8. The national average for electricity cost is about $0.10 per
kilowatt-hour or $0.0001per watt-hour.
9. The time required to recoup the initial investment in wire is
$10.95/($0.0001 x 5.01) equals 21,856 hours at full load.
10. At an average of 10 hours per week at full load, it will only
take him 42 years to recoup his investment. After that, it's all
gravy.
DonkeyHody
"In theory, theory and practice are the same, but in practice, they
are not."
>
> No one has defined the application so we don't know if this is a case
> where a cord out in an exposed area or conductors in a secure space such
> as in a conduit or behind a wall are required.
>
> If it is a cord application, then Romex would not be appropriate.
>
> If it is a set of conductors in a secure space, then the cord would not
> be appropriate.
>
> In either case, any attempt at comparison between the two would be moot.
>
True, but you failed to consider that romex might be appropriate when
you proposed a #10 cordset as the "lowest cost solution available".
> BTW, if you are aware of what is happening in the raw materials market
> these days, especially copper which has a history of being volatile, you
> would also be aware that only a fool would quote anything but "price in
> effect at time of shipment", and that includes the lowly hardware store
> down the street that is going to cut a piece of something off a roll
> that was purchased 6-9 months ago.
>
> Never sold wire but was around the business. Not uncommon to have a
> price on wire be good only for the day, sometimes two.
>
> Electrical contractors typically make a buy on wire on a job as a
> specific commodity, just like the apparatus or the lighting.
OK, but when the cost of #14 goes up, so does the cost of #10.
> As far as the cost of power is concerned, think you will find the
> residential/small commercial market is somewhere around $0.15-$0.17/KWH
> unless it is being subsidized in some fashion.
>
> The days of $0.10/KWH disappeared with the buggy whip.
>
Maybe where you live, but I pay $0.087/KWH. My estimate of $0.10/KWH
for a national average wasn't pulled out of the air. Here's a couple
of links.
http://www.entergy-mississippi.com/content/price/bills/Ms-bill.pdf
http://www.eia.doe.gov/cneaf/electricity/epm/epm_sum.html
> Now, let's talk about line losses.
>
> Line losses are a two edged sword.
>
> First, you pay for the lost power and turn it into heat. Heating up a
> conductor raises the temperature of the insulation around the
> conductors, thus shortening the insulation life.
>
> 2nd, the line losses reduce the amount of power delivered to the load by
> reducing the voltage at the terminals of the load, which in this case
> would appear to be a saw or an air compressor.
>
> Reducing the voltage delivered requires that the current be increased to
> get the same amount of work done.
>
> Again, increasing the current in the motor windings, increases the heat,
> which reduces the life of the insulation of the motor.
>
> Calculation of the economics is based on the ability of the buyer to get
> a deal; however, the bottom line when it comes to electrical conductors
> is that bigger is better when it comes to distribution conductors.
>
> Trust me<G>
>
> Lew
Sorry Lew, but I just don't trust you <G>.
While your line-loss argument is valid for a conductor that is
marginal or undersized for the load, the law of diminishing returns
catches up pretty quick. I simply don't accept your assertion that an
11 amp load heats #14 wire enough to degrade the insulation. The wire
length required to get a 2% voltage drop on #14 wire at 10 amps is 90
feet. At 30 feet of total wire length (15 ft x 2), voltage drop and
heat simply won't be a big factor in this application. #14 is
adequate. #12 is what I would use. #10 won't hurt anything.
My whole point is this. After your wire size is adequate for the
task, you can't just arbitrarily jump up a couple of sizes and say,
"Oh well, the electricity savings will pay for it." In an industrial
application where the wire you install powers a motor that runs 24/7
at full load, maybe; but in a home shop environment, we may not live
long enough to see the payback.
I think we done beat this horse to death. You have a nice day.
DonkeyHody
"In theory, theory and practice are the same, but in practice, they
are not."
On Mar 18, 6:30 am, "DonkeyHody" <[email protected]> wrote:
> While your line-loss argument is valid for a conductor that is
> marginal or undersized for the load, the law of diminishing returns
> catches up pretty quick.
Agreed. With a caveat.
> I simply don't accept your assertion that an
> 11 amp load heats #14 wire enough to degrade the insulation.
Don't assume that your 14 ga conductor from an off-shore source has Cu
purity levels for them to play by North American charts. Same thing
for their insulation standards. Also, thermal increases along the
length due to resistance is not linear with conductor length. Add to
that, that inductive loads on a partially coiled 14 ga wire with an 11
amp load can geberate localized heat, and the whole 'perfect' argument
goes out the window.
I have seen, with my own eyes, that 50' cords from off-shore suppliers
(which means most cords) rated at 14 gauge AWG shrivel up into snake-
mottling-like messes by ordinary uses on jobsites. And we're not
talking about tables-saws or compressors either.
> My whole point is this. After your wire size is adequate for the
> task, you can't just arbitrarily jump up a couple of sizes and say,
> "Oh well, the electricity savings will pay for it." In an industrial
> application where the wire you install powers a motor that runs 24/7
> at full load, maybe; but in a home shop environment, we may not live
> long enough to see the payback.
The argument you make about pay-back makes sense.... from 12 gauge on
up.
>
> "In theory, theory and practice are the same, but in practice, they
> are not."
You said it.
Too bad the horse is dead. Maybe some mouth-to-mouth?
> One final thought.
>
> If this discussion has raised the awareness of the group to the fallacy
> of trying to use relatively small conductor size extension cords for
> relatively long applications, it will have served it's purpose.
>
> Lew
Oh, you mean other people besides me and you are still following this
tread?
And a fine and pleasant discussion it's been too.
But I still don't trust you. <G>
DonkeyHody
"We should be careful to get out of an experience only the wisdom
that is in it - and stop there; lest we be like the cat that sits
down
on a hot stove-lid. She will never sit down on a hot stove-lid
again---and that is well; but also she will never sit down on a cold
one anymore." - Mark Twain
Robatoy wrote:
> On Mar 14, 7:42 pm, Lew Hodgett <[email protected]> wrote:
> [schnipf]
>
>> chop off the
>> ends, and rewire as necessary.
>>
> ..won't the voltages leak out when you cut it?
>
>
More likely that it will spray all over the place at 220v. Lotsa
pressure there. Probably even duct tape wouldn't hold it back.
Not to worry about the volts, it's the smoke leaking out that causes
problems. Poorly wired or insulated wire often leaks smoke which causes a
myriad of problems.
Paul
"Robatoy" <[email protected]> wrote in message
news:[email protected]...
> On Mar 14, 7:42 pm, Lew Hodgett <[email protected]> wrote:
> [schnipf]
>
>> chop off the
>> ends, and rewire as necessary.
>>
> ..won't the voltages leak out when you cut it?
>
>
Jimmy wrote:
> I have to run a 220v 14amp line about 15 ft. Will a line of 14/2 work or
> will there be a problem with the wire getting too hot? The motor says it
> pulls 11amps.
>
> Thanks
> Jimmy
>
>
14 gauge wire is rated for a max of 15 amps. As long as you use a 15
amp breaker/fuse it will be safe.
--
Jack Novak
Buffalo, NY - USA
[email protected]
Robatoy wrote:
> On Mar 14, 8:38 pm, Unquestionably Confused <[email protected]>
> wrote:
>
>> . Probably even duct tape wouldn't hold it back.
>
> Even though duct tape is shiny?
No chance. That shiny surface is slick. Less resistance, the little
volty things will really fly!
"Lew Hodgett" <[email protected]> wrote in message
news:hL%[email protected]...
> Jimmy wrote:
> > I have to run a 220v 14amp line about 15 ft. Will a line of 14/2
> work or
> > will there be a problem with the wire getting too hot? The motor
> says it
> > pulls 11amps.
>
> Wire is CHEAP by comparison to other thing electrical including the cost
> of electricity.
>
> #14 AWG will handle it legally; however, the line drop introduced by using
> a small wire #14 AWG) will bite you in the ass every month when the
> electricity bill hits your door step because you have to pay for all that
> wasted power caused by using a small wire at high load.
>
The voltage drop cause by running a 240v 11a max motor over 15' of #14 is
too trivial to consider.
> Buy a 10-2 with ground, molded cord set, 25 ft long, chop off the ends,
> and rewire as necessary.
>
You must be joking about this.
OP, if you have #14, use it. If you have both (or neither) use #12 since
the price difference is small and you might want a 20a circuit there some
day.
Jimmy wrote:
> I have to run a 220v 14amp line about 15 ft. Will a line of 14/2
work or
> will there be a problem with the wire getting too hot? The motor
says it
> pulls 11amps.
Wire is CHEAP by comparison to other thing electrical including the
cost of electricity.
#14 AWG will handle it legally; however, the line drop introduced by
using a small wire #14 AWG) will bite you in the ass every month when
the electricity bill hits your door step because you have to pay for
all that wasted power caused by using a small wire at high load.
Buy a 10-2 with ground, molded cord set, 25 ft long, chop off the
ends, and rewire as necessary.
It is the lowest cost solution available, trust me.
Have fun.
Lew
DonkeyHody wrote:
>
> Sorry Lew, but I get suspicious when somebody says "trust me".
> Normally, I would let this one slide. After all, the worst that might
> happen if he follows your advice is that he might spend an extra few
> bucks on wire. But it's a slow day at the office, so I decided to run
> some numbers.
>
> 1. A 25 ft. 10-3 extension cord costs about $25.00 say $1.00 per
> foot.
> 2. 14-2 w/g Romex costs about $0.27 cents a foot
> 3. The difference of $0.73 per foot x 15 feet equals a materials cost
> difference of $10.95 for the job.
>
> 4. #14 wire has a resistance of about 0.00258 ohms per foot
> 5. #10 wire has a resistance of about 0.00120 ohms per foot
> 6. 0.00138 ohms difference x 30 foot total run equals 0.0414 ohms
> difference in resistance between the two proposed types of wire.
>
> 7. The power lost in a wire equals the current (squared) x
> resistance. At 11 amps load, the difference in power lost is 0.0414 x
> 11(squared) equals 5.01 watts.
> 8. The national average for electricity cost is about $0.10 per
> kilowatt-hour or $0.0001per watt-hour.
> 9. The time required to recoup the initial investment in wire is
> $10.95/($0.0001 x 5.01) equals 21,856 hours at full load.
> 10. At an average of 10 hours per week at full load, it will only
> take him 42 years to recoup his investment. After that, it's all
> gravy.
A little knowledge and some extra time on your hands can produce some
interesting results<G>.
Let's take it from the top.
No one has defined the application so we don't know if this is a case
where a cord out in an exposed area or conductors in a secure space such
as in a conduit or behind a wall are required.
If it is a cord application, then Romex would not be appropriate.
If it is a set of conductors in a secure space, then the cord would not
be appropriate.
In either case, any attempt at comparison between the two would be moot.
BTW, if you are aware of what is happening in the raw materials market
these days, especially copper which has a history of being volatile, you
would also be aware that only a fool would quote anything but "price in
effect at time of shipment", and that includes the lowly hardware store
down the street that is going to cut a piece of something off a roll
that was purchased 6-9 months ago.
Never sold wire but was around the business. Not uncommon to have a
price on wire be good only for the day, sometimes two.
Electrical contractors typically make a buy on wire on a job as a
specific commodity, just like the apparatus or the lighting.
As far as the cost of power is concerned, think you will find the
residential/small commercial market is somewhere around $0.15-$0.17/KWH
unless it is being subsidized in some fashion.
The days of $0.10/KWH disappeared with the buggy whip.
Now, let's talk about line losses.
Line losses are a two edged sword.
First, you pay for the lost power and turn it into heat. Heating up a
conductor raises the temperature of the insulation around the
conductors, thus shortening the insulation life.
2nd, the line losses reduce the amount of power delivered to the load by
reducing the voltage at the terminals of the load, which in this case
would appear to be a saw or an air compressor.
Reducing the voltage delivered requires that the current be increased to
get the same amount of work done.
Again, increasing the current in the motor windings, increases the heat,
which reduces the life of the insulation of the motor.
Calculation of the economics is based on the ability of the buyer to get
a deal; however, the bottom line when it comes to electrical conductors
is that bigger is better when it comes to distribution conductors.
Trust me<G>
Lew
DonkeyHody wrote:
> True, but you failed to consider that romex might be appropriate when
> you proposed a #10 cordset as the "lowest cost solution available".
If you need a cord, buying a molded cord set will be lowest cost solution.
> I simply don't accept your assertion that an
> 11 amp load heats #14 wire enough to degrade the insulation.
Sounds like a personal problem to me<G>.
Everything, including man, starts the inevitable march to the junk yard,
the day it is put in service.
An 11A load on a #14AWG wire, produces heat.
Heat is the enemy of insulation.
Sooner or later it bites you.
> The wire
> length required to get a 2% voltage drop on #14 wire at 10 amps is 90
> feet. At 30 feet of total wire length (15 ft x 2), voltage drop and
> heat simply won't be a big factor in this application. #14 is
> adequate. #12 is what I would use. #10 won't hurt anything.
SFWIW, what some often forget in these discussions is the 80% rule.
The full load continuous current permitted by a molded case circuit such
as found in the typical load center or panelboard is 80% of the
nameplate value as defined by NEC.
Thus a 15A C'Bkr, used for #14AWG conductor protection, will allow 12A
(15x80%) on a continuous basis.
Above 12A, you are operating on the time derate curve of the C'Bkr.
Your choice of #12AWG for this application is an improvement over
#14AWG, and is economically a good one.
Many years ago, I decided not to worry about wire size and standardized
on #10AWG for all cordage applications in my shop.
Strictly a personal choice.
I have found that with a little patience and making purchases when you
are not under the gun, you often find sales on things including #10AWG
cord sets, which is when I buy them; however, even at full price, the
difference between #12AWG and #10AWG, 25 ft molded cord sets rarely
exceeds the cost of a decent 12 pack.
> My whole point is this. After your wire size is adequate for the
> task, you can't just arbitrarily jump up a couple of sizes and say,
> "Oh well, the electricity savings will pay for it."
As indicated, power savings alone is not the total answer. It is a
combination of power savings and insulation life of not only the
conductors, but also the power consuming device.
Trying to calculate the cost of reduced insulation life is an exercise I
leave to others.
> In an industrial
> application where the wire you install powers a motor that runs 24/7
> at full load, maybe; but in a home shop environment, we may not live
> long enough to see the payback.
Actually, in an industrial application, the payback period rarely
exceeds 2 years, thus they tend not to have much spare capacity in their
designs.
> I think we done beat this horse to death. You have a nice day.
OK.
One final thought.
If this discussion has raised the awareness of the group to the fallacy
of trying to use relatively small conductor size extension cords for
relatively long applications, it will have served it's purpose.
Lew
The small price difference between 14 gauge and 12 gauge for that short of a
run, I would run the 12 gauge. Sounds like there is about a 3 hp motor at
the end of this. Speculation would be a table saw. If the guess is correct
the "extra" wire gauge would be the better bet. Good luck
"Jimmy" <[email protected]> wrote in message
news:[email protected]...
>I have to run a 220v 14amp line about 15 ft. Will a line of 14/2 work or
>will there be a problem with the wire getting too hot? The motor says it
>pulls 11amps.
>
> Thanks
> Jimmy
>