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Henry July 9th 07 10:42 PM

12 amp wire size
 
I was wondering what cable size to use for wiring a 125V 12 amp fan that is
100 feet away from the breaker panel.

Thanks.

Rich July 9th 07 10:53 PM

12 amp wire size
 
Henry wrote:
I was wondering what cable size to use for wiring a 125V 12 amp fan
that is 100 feet away from the breaker panel.

Thanks.


http://www.wiktel.com/standards/wiresize.htm

Rich



Jeff Wisnia July 9th 07 11:00 PM

12 amp wire size
 
Henry wrote:
I was wondering what cable size to use for wiring a 125V 12 amp fan that is
100 feet away from the breaker panel.

Thanks.



You should be able to use 14 gauge wire.

It'll drop about 4 volts at 12 amps over that length, but that shouldn't
worry a fan much.

HTH,

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.


Toller July 9th 07 11:07 PM

12 amp wire size
 

"Jeff Wisnia" wrote in message
...
Henry wrote:
I was wondering what cable size to use for wiring a 125V 12 amp fan that
is 100 feet away from the breaker panel.

Thanks.



You should be able to use 14 gauge wire.

It'll drop about 4 volts at 12 amps over that length, but that shouldn't
worry a fan much.

You could use #14, but there will be a lot of VD at startup, which won't be
too good for the fan.
#12 isn't all that much more expensive.



dpb July 9th 07 11:10 PM

12 amp wire size
 
Toller wrote:
"Jeff Wisnia" wrote in message
...
Henry wrote:
I was wondering what cable size to use for wiring a 125V 12 amp fan that
is 100 feet away from the breaker panel.

Thanks.


You should be able to use 14 gauge wire.

It'll drop about 4 volts at 12 amps over that length, but that shouldn't
worry a fan much.

You could use #14, but there will be a lot of VD at startup, ...


How did you determine that, and how much, specifically, are you thinking
is "a lot" for a fractional hp fan motor???

#12 isn't all that much more expensive.


That's true, certainly, and I have pretty much quit using 14, but if
it's a dedicated circuit I don't think there's a chance in the world the
difference would make any practical difference at all.

If, otoh, there's a chance of wanting something else, that would
necessitate it in all likelihood.

--

Chris Lewis July 9th 07 11:43 PM

12 amp wire size
 
According to Meat Plow :
On Mon, 09 Jul 2007 17:10:50 -0500, dpb wrote:


Toller wrote:
"Jeff Wisnia" wrote in message
...
Henry wrote:
I was wondering what cable size to use for wiring a 125V 12 amp fan that
is 100 feet away from the breaker panel.

Thanks.

You should be able to use 14 gauge wire.

It'll drop about 4 volts at 12 amps over that length, but that shouldn't
worry a fan much.

You could use #14, but there will be a lot of VD at startup, ...


How did you determine that, and how much, specifically, are you thinking
is "a lot" for a fractional hp fan motor???


Not to nitpick but wouldn't a motor drawing 12 running amps (if the OP is
correct) be in the realm of a couple hp? If I recall my 5 hp compressor
motor draws around 12.


Not at 120V it don't. A "true" 5HP motor will draw somewhere around 40A
on 120V, or 20A on 240V. (On motors = 1HP, count on approximately
900-1000W/HP because of inefficiencies. Yes, I know, the exact conversion
is 746W/HP, but no motor is 100% efficient)

At 120V, a standard 12A motor is probably between 3/4 and 1HP, tho possibly
as low as 1/2HP. Not lower unless it's a real lousy or poorly spec'd
motor. (Serious fan in any case...)

A 12A motor can draw well over three (or even five) times that much during
startup. 12V or more drop (assuming the previous math was right) at 100'.
That's a significant amount, and will significantly prolong startup and
produce more heat, and ultimately shorten the fan motor's lifetime. Perhaps
by not much, but perhaps by quite a bit.

This is a good place to go up a wire size. It's cheap.
--
Chris Lewis,

Age and Treachery will Triumph over Youth and Skill
It's not just anyone who gets a Starship Cruiser class named after them.

Jeff Wisnia July 9th 07 11:51 PM

12 amp wire size
 
Toller wrote:

"Jeff Wisnia" wrote in message
...

Henry wrote:

I was wondering what cable size to use for wiring a 125V 12 amp fan that
is 100 feet away from the breaker panel.

Thanks.



You should be able to use 14 gauge wire.

It'll drop about 4 volts at 12 amps over that length, but that shouldn't
worry a fan much.


You could use #14, but there will be a lot of VD at startup, which won't be
too good for the fan.
#12 isn't all that much more expensive.



You're correct about that, and using 12 gauge might be a wise investment.

Currently Lowes' price for 100 ft of 14 gauge is $36.00 vs. $52.50 for
12 gauge.

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.


Toller July 10th 07 12:39 AM

12 amp wire size
 

How did you determine that, and how much, specifically, are you thinking
is "a lot" for a fractional hp fan motor???


Don't know who you are; I have you blocked for the stupid things you have
said in the past.
For good reason, here is one more!
12a is not a fractional hp motor. Don't you even bother to read the posts?



Edwin Pawlowski July 10th 07 03:05 AM

12 amp wire size
 

"Jeff Wisnia" wrote in message
...
Henry wrote:
I was wondering what cable size to use for wiring a 125V 12 amp fan that
is 100 feet away from the breaker panel.

Thanks.



You should be able to use 14 gauge wire.

It'll drop about 4 volts at 12 amps over that length, but that shouldn't
worry a fan much.


Borderline on a 15A circuit. 12 ga. would be better. 20 A breaker



Steve Barker July 10th 07 03:24 AM

12 amp wire size
 
12/2 on a 20a breaker will more than suffice.

--
Steve Barker







"Henry" wrote in message
...
I was wondering what cable size to use for wiring a 125V 12 amp fan that is
100 feet away from the breaker panel.

Thanks.




Steve Barker July 10th 07 03:26 AM

12 amp wire size
 
52.50? that sounds like a 200' price to me.

--
Steve Barker







"Jeff Wisnia" wrote in message
...
You're correct about that, and using 12 gauge might be a wise investment.

Currently Lowes' price for 100 ft of 14 gauge is $36.00 vs. $52.50 for 12
gauge.

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.




July 10th 07 06:21 AM

12 amp wire size
 

"Jeff Wisnia" wrote in message
...
Henry wrote:
I was wondering what cable size to use for wiring a 125V 12 amp fan that

is
100 feet away from the breaker panel.

Thanks.



You should be able to use 14 gauge wire.

It'll drop about 4 volts at 12 amps over that length, but that shouldn't
worry a fan much.



Ever read the NEC for voltage drop allowances?




kool July 10th 07 05:58 PM

12 amp wire size
 
How do they rate air compressors at 5HP when they have a 3/4 or 1 HP motor
driving it?

"Meat Plow" wrote in message
...
On Mon, 09 Jul 2007 17:10:50 -0500, dpb wrote:

Toller wrote:
"Jeff Wisnia" wrote in message
...
Henry wrote:
I was wondering what cable size to use for wiring a 125V 12 amp fan
that
is 100 feet away from the breaker panel.

Thanks.

You should be able to use 14 gauge wire.

It'll drop about 4 volts at 12 amps over that length, but that
shouldn't
worry a fan much.

You could use #14, but there will be a lot of VD at startup, ...


How did you determine that, and how much, specifically, are you thinking
is "a lot" for a fractional hp fan motor???


Not to nitpick but wouldn't a motor drawing 12 running amps (if the OP is
correct) be in the realm of a couple hp? If I recall my 5 hp compressor
motor draws around 12.


#12 isn't all that much more expensive.


That's true, certainly, and I have pretty much quit using 14, but if
it's a dedicated circuit I don't think there's a chance in the world the
difference would make any practical difference at all.

If, otoh, there's a chance of wanting something else, that would
necessitate it in all likelihood.





Chris Lewis July 10th 07 06:40 PM

12 amp wire size
 
According to Meat Plow :

I used to work with Baldor repulsion/induction motors in the oilfield.
There were all 240v, 15 hp. If memory serves, on the well upstroke they
drew around 30 amps and otherwise around 18.


240V at 30A is 7200W, which means that during the upstroke those
motors were delivering somewhere around 6-8 HP. Conservative
motor selection, given that weather/rig conditions etc could cause
the motor to need more.

It would have been interesting to compare that with the motor
plate ratings, or know what size the fuses/breakers were.
--
Chris Lewis,

Age and Treachery will Triumph over Youth and Skill
It's not just anyone who gets a Starship Cruiser class named after them.

Mark Lloyd July 10th 07 09:19 PM

12 amp wire size
 
On Tue, 10 Jul 2007 15:25:35 -0400, wrote:

On Tue, 10 Jul 2007 17:40:08 -0000,
(Chris
Lewis) wrote:

According to Meat Plow :

I used to work with Baldor repulsion/induction motors in the oilfield.
There were all 240v, 15 hp. If memory serves, on the well upstroke they
drew around 30 amps and otherwise around 18.


240V at 30A is 7200W, which means that during the upstroke those
motors were delivering somewhere around 6-8 HP. Conservative
motor selection, given that weather/rig conditions etc could cause
the motor to need more.

It would have been interesting to compare that with the motor
plate ratings, or know what size the fuses/breakers were.



Don't let that theoretical 800w per HP confuse you. Motors never get
close to that efficiency. A typical 1HP motor will pull more like
12-13a @ 120v (my C/H compressor) and some cheap ones will be more
like 15-16a.


Lowe's claims to have a 3HP electric chain saw, that still works on a
15A receptacle.
--
Mark Lloyd
http://notstupid.laughingsquid.com

"Unlike biological evolution. 'intelligent design' is
not a genuine scientific theory and, therefore, has
no place in the curriculum of our nation's public
school classes." -- Ted Kennedy

Jeff Wisnia July 10th 07 11:47 PM

12 amp wire size
 
kool wrote:

How do they rate air compressors at 5HP when they have a 3/4 or 1 HP motor
driving it?




AFAIK that's some a not very useful rating called "peak horsepower"
which I believe is the horsepower which can be delivered for a VERY
brief time if the motor is up to speed and you suddenly apply a heavy
torque load to it.

I think the energy must come from inertial storage in the rotating
parts, but it gets "used up" pretty quickly and the motor HAS to slow
down (and burn up?)

If someone has a better explanation, or a cite to an industry standard
definition, I'm all ears.

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.


Steve Barker July 11th 07 01:20 AM

12 amp wire size
 
yep. $49.99 locally for the 200' rolls of 12/2wg NMB. I price it every
time I go out (almost every day) as I have rentals that need wire and also
my own house is still not quite finished in the wiring dept.

--
Steve Barker







"Doug Miller" wrote in message
t...
In article , "Steve Barker"
wrote:
52.50? that sounds like a 200' price to me.

Priced copper wire recently?

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.




Mike Dobony July 11th 07 03:11 AM

12 amp wire size
 

"Jeff Wisnia" wrote in message
...
kjpro @ usenet.com wrote:

"Jeff Wisnia" wrote in message
...

Henry wrote:

I was wondering what cable size to use for wiring a 125V 12 amp fan that


is

100 feet away from the breaker panel.

Thanks.


You should be able to use 14 gauge wire.

It'll drop about 4 volts at 12 amps over that length, but that shouldn't
worry a fan much.




Ever read the NEC for voltage drop allowances?




Not recently, but if I advised something which wouldn't meet code then I
apologize and stand corrected.

I just figured that a 4 volt drop would still furnish a fan motor with
sufficient power to do its thing.


What type of fan? A box fan only has a 16ga wire on it. If it is rated for
12a. then that is probably the max draw on startup. 14 ga would do well,
assuming romax, not extension cord. Still, why bother with 14 ga. Go with
the standard 12 ga and put in a 20a breaker.



Dave Martindale July 11th 07 05:10 AM

12 amp wire size
 
Mark Lloyd writes:

Lowe's claims to have a 3HP electric chain saw, that still works on a
15A receptacle.


Assuming it's not simply a baldfaced lie, that is an intermittent
rating. As in "if you load this motor with a brake to the point where
it produces maximum output in overload, it's producing 3 HP - until the
circuit breaker trips or the motor burns up, whichever comes first".

The rating might actually make a bit of sense for a chainsaw, where
hitting a hard spot *will* cause the motor to put out more power
temporarily, and where you're comparing against gas-powered motors where
the HP rating is the maximum HP available.

But it's not comparable to induction motor ratings, where "1 HP" generally
means it will deliver 1 HP all day, and nearly 2 HP momentarily when
overloaded.

Rating continuous-running things like shop vacs and air compressors in
"peak HP" is completely bogus, of course.

Dave

mm July 12th 07 06:42 AM

12 amp wire size
 
On Tue, 10 Jul 2007 19:20:10 -0500, "Steve Barker"
wrote:

yep. $49.99 locally for the 200' rolls of 12/2wg NMB. I price it every
time I go out (almost every day) as I have rentals that need wire and also
my own house is still not quite finished in the wiring dept.


You must have a lot of rentals or they must use a lot of wire!

This reminds me of a friend at work who says his wife wants a lot of
money:

"Every day my wife asks me for 200 dollars, every day!"

"Wow," I say, "What does she do with all that money?"

"I don't know. I never give it to her."


Chris Lewis July 12th 07 07:04 PM

12 amp wire size
 
According to :
On Tue, 10 Jul 2007 17:40:08 -0000, (Chris
Lewis) wrote:

According to Meat Plow :

I used to work with Baldor repulsion/induction motors in the oilfield.
There were all 240v, 15 hp. If memory serves, on the well upstroke they
drew around 30 amps and otherwise around 18.


240V at 30A is 7200W, which means that during the upstroke those
motors were delivering somewhere around 6-8 HP. Conservative
motor selection, given that weather/rig conditions etc could cause
the motor to need more.

It would have been interesting to compare that with the motor
plate ratings, or know what size the fuses/breakers were.



Don't let that theoretical 800w per HP confuse you.


In case it wasn't clear, I wasn't confused ;-)

Motors never get
close to that efficiency. A typical 1HP motor will pull more like
12-13a @ 120v (my C/H compressor) and some cheap ones will be more
like 15-16a.


Once you get into multi-horsepower industrial-grade motors,
rule-of-thumb is about 1000 watts per HP. At 1-2HP and below,
they're not as efficient and 12-13A/HP is a reasonable ballpark at
the high end. Once you get to 1/4HP and below, motors can be
stupidly inefficient. Eg: the 1/4HP motor I saw whose label
said 10A.
--
Chris Lewis,

Age and Treachery will Triumph over Youth and Skill
It's not just anyone who gets a Starship Cruiser class named after them.

Chris Lewis July 12th 07 07:07 PM

12 amp wire size
 
According to Dave Martindale :
Mark Lloyd writes:


Lowe's claims to have a 3HP electric chain saw, that still works on a
15A receptacle.


Assuming it's not simply a baldfaced lie, that is an intermittent
rating. As in "if you load this motor with a brake to the point where
it produces maximum output in overload, it's producing 3 HP - until the
circuit breaker trips or the motor burns up, whichever comes first".


Yes. It's an instantaneous max HP, rather than a safe continuous
rating. Shop vacuums and routers are infamous for using these inflated
figures. Instantaneous max HP is a useful measure on a router or
chain saw in some cases, but is useless to a shop vacuum.
--
Chris Lewis,

Age and Treachery will Triumph over Youth and Skill
It's not just anyone who gets a Starship Cruiser class named after them.


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