John Wentworth wrote:
"Mys Terry" wrote in message
...

The distance in this case is a pretty important factor. I don't think
a 15 amp "tool" is going to be very happy on a 100 foot 12 gauge cord.



You're correct. To have a not greater than 3% voltage drop, a 15 amp load
on a 100 foot cable would require #8 wire.
See http://www.elec-toolbox.com/calculators/voltdrop.htm for a voltage drop
calculator.



Contractors use 100' 12ga extension cords every day to power large saws,
rotary hammer drills, and other big tools powered by their generators.
10ga or bigger would be expensive, hard to find, and not necessary.

Dan

On Sat, 08 Apr 2006 00:54:50 GMT, Dan Krueger
wrote:

John Wentworth wrote:
"Mys Terry" wrote in message
...

The distance in this case is a pretty important factor. I don't think
a 15 amp "tool" is going to be very happy on a 100 foot 12 gauge cord.



You're correct. To have a not greater than 3% voltage drop, a 15 amp load
on a 100 foot cable would require #8 wire.
See http://www.elec-toolbox.com/calculators/voltdrop.htm for a voltage drop
calculator.



Contractors use 100' 12ga extension cords every day to power large saws,
rotary hammer drills, and other big tools powered by their generators.
10ga or bigger would be expensive, hard to find, and not necessary.

Dan

Exactly correct. The calculator referenced only allows a 3% voltage
drop, which is only 3.6V for a nominal 120V ac circuit. Maybe if
you're running sensitive medical equipment that's necessary, but not
for power tools. A 15 amp circular hand saw is perfectly "happy"
running on 105V or so, over a 10% drop.

Think of it this way... your home wiring is usually 14ga for normal 15
amp branch circuits. Not unusual to have a 100ft run between the
breaker box and the outlets. Some voltage drop is expected, and
safety factors are built into everything you buy.

Jack

"Jack Goff" wrote in message
...
On Sat, 08 Apr 2006 00:54:50 GMT, Dan Krueger
wrote:

John Wentworth wrote:
"Mys Terry" wrote in message
...

The distance in this case is a pretty important factor. I don't think
a 15 amp "tool" is going to be very happy on a 100 foot 12 gauge cord.



You're correct. To have a not greater than 3% voltage drop, a 15 amp
load
on a 100 foot cable would require #8 wire.
See http://www.elec-toolbox.com/calculators/voltdrop.htm for a voltage
drop
calculator.



Contractors use 100' 12ga extension cords every day to power large saws,
rotary hammer drills, and other big tools powered by their generators.
10ga or bigger would be expensive, hard to find, and not necessary.

Dan

Exactly correct. The calculator referenced only allows a 3% voltage
drop, which is only 3.6V for a nominal 120V ac circuit. Maybe if
you're running sensitive medical equipment that's necessary, but not
for power tools. A 15 amp circular hand saw is perfectly "happy"
running on 105V or so, over a 10% drop.

Think of it this way... your home wiring is usually 14ga for normal 15
amp branch circuits. Not unusual to have a 100ft run between the
breaker box and the outlets. Some voltage drop is expected, and
safety factors are built into everything you buy.

Jack


15 amp circuits are 14 gauge, and few run 100' inside a house. More like
50' at most. Contractors use 12 gauge because you can move the cord. And
most saws and tools are built to run in a 15 amp circuit, not draw 15 amps.
Most are in the 7-8 amp range.

CalifBill wrote:


15 amp circuits are 14 gauge, and few run 100' inside a house. More like
50' at most. Contractors use 12 gauge because you can move the cord. And
most saws and tools are built to run in a 15 amp circuit, not draw 15 amps.
Most are in the 7-8 amp range.



Maybe your rinky-dink Black & Decker stuff is 7 amps....
My Makita circular saw is 13 amps...
my Craftsman electric chain saw is 12 amps
my Toro Electric snowthrower is 12 amps...
etc...

On Sat, 08 Apr 2006 12:33:31 GMT, Don White
wrote:

CalifBill wrote:


15 amp circuits are 14 gauge, and few run 100' inside a house. More like
50' at most. Contractors use 12 gauge because you can move the cord. And
most saws and tools are built to run in a 15 amp circuit, not draw 15 amps.
Most are in the 7-8 amp range.



Maybe your rinky-dink Black & Decker stuff is 7 amps....
My Makita circular saw is 13 amps...
my Craftsman electric chain saw is 12 amps
my Toro Electric snowthrower is 12 amps...
etc...

Like my other post explains, that's the maximum current those items
will daw when doing the maximum work they are rated for. Typical
current will be a lot less. Basically, the current *required* by the
motor varies depending on the load *placed* on the motor.

ELECTRIC chainsaw?!? You girlie-man... :-)

Jack

Jack Goff wrote:
snip...

ELECTRIC chainsaw?!? You girlie-man... :-)

Jack


Girlie-man???
I live on a 40' x 100' city lot. The trees on it are too big to tackle
by myself if I used a 20" gas chainsaw. (other than a bit of pruning or
cutting up firewood already on the ground).
Just this week we paid $500.00 + tax to have a very large Ash tree
felled on our front lawn because the wife would be on pins & needles
every time the wind blew.

For my use this 12amp electric chainsaw is very practical and performs well.
Who's the girlie-man?

On Sat, 08 Apr 2006 14:38:08 GMT, Don White
wrote:

Jack Goff wrote:
snip...

ELECTRIC chainsaw?!? You girlie-man... :-)

Jack


Girlie-man???
I live on a 40' x 100' city lot. The trees on it are too big to tackle
by myself if I used a 20" gas chainsaw. (other than a bit of pruning or
cutting up firewood already on the ground).
Just this week we paid $500.00 + tax to have a very large Ash tree
felled on our front lawn because the wife would be on pins & needles
every time the wind blew.

For my use this 12amp electric chainsaw is very practical and performs well.
Who's the girlie-man?

Pay attention to the smilie-face. :-)

I understand. I used to have one of those homeowner-grade Poulan gas
chainsaws. I was OK for cutting up limbs and such, but had the
smaller size chain and a small motor, so it just couldn't handle
bigger jobs. At the time, that was OK for my situation.

I'm now on 2+ acres, and it's 80% heavily wooded. The Poulan died, so
I bought a real saw... a Stihl. I've paid to have a couple of large
oaks taken down that were too close to the house for me to do, but the
Stihl has paid for itself on a couple of other trees I could handle
myself.

Jack

"Don White" wrote in message
...
CalifBill wrote:


15 amp circuits are 14 gauge, and few run 100' inside a house. More like
50' at most. Contractors use 12 gauge because you can move the cord.
And most saws and tools are built to run in a 15 amp circuit, not draw 15
amps. Most are in the 7-8 amp range.

Maybe your rinky-dink Black & Decker stuff is 7 amps....
My Makita circular saw is 13 amps...
my Craftsman electric chain saw is 12 amps
my Toro Electric snowthrower is 12 amps...
etc...

That is with the blade almost locked or starting for a very short time. I
run a Skil Mag 77 worm drive and it is rated 13 amps. If they drew 15 amps
the circuit breaker would always be tripping.

On Sun, 09 Apr 2006 03:47:35 GMT, "Calif Bill"
wrote:


"Don White" wrote in message
...
CalifBill wrote:


15 amp circuits are 14 gauge, and few run 100' inside a house. More like
50' at most. Contractors use 12 gauge because you can move the cord.
And most saws and tools are built to run in a 15 amp circuit, not draw 15
amps. Most are in the 7-8 amp range.

Maybe your rinky-dink Black & Decker stuff is 7 amps....
My Makita circular saw is 13 amps...
my Craftsman electric chain saw is 12 amps
my Toro Electric snowthrower is 12 amps...
etc...

That is with the blade almost locked or starting for a very short time. I
run a Skil Mag 77 worm drive and it is rated 13 amps. If they drew 15 amps
the circuit breaker would always be tripping.

Remember that a 15 amp circuit breaker can carry far more than 15 amps
for a period of time. Circuit breaker have "trip curves", and a
typical 15 amp breaker can carry 15 amps for over 15 MINUTES before
tripping. At 30 amps it takes 7 seconds to trip, and at 60 amps it
still takes 1 second.

A 15 amp saw, dynamically drawing 15+ amps, would pose no problem for
a 15 amp breaker.

Jack

"Jack Goff" wrote in message
...
On Sun, 09 Apr 2006 03:47:35 GMT, "Calif Bill"
wrote:


"Don White" wrote in message
...
CalifBill wrote:


15 amp circuits are 14 gauge, and few run 100' inside a house. More
like
50' at most. Contractors use 12 gauge because you can move the cord.
And most saws and tools are built to run in a 15 amp circuit, not draw
15
amps. Most are in the 7-8 amp range.

Maybe your rinky-dink Black & Decker stuff is 7 amps....
My Makita circular saw is 13 amps...
my Craftsman electric chain saw is 12 amps
my Toro Electric snowthrower is 12 amps...
etc...

That is with the blade almost locked or starting for a very short time. I
run a Skil Mag 77 worm drive and it is rated 13 amps. If they drew 15
amps
the circuit breaker would always be tripping.

Remember that a 15 amp circuit breaker can carry far more than 15 amps
for a period of time. Circuit breaker have "trip curves", and a
typical 15 amp breaker can carry 15 amps for over 15 MINUTES before
tripping. At 30 amps it takes 7 seconds to trip, and at 60 amps it
still takes 1 second.

A 15 amp saw, dynamically drawing 15+ amps, would pose no problem for
a 15 amp breaker.

Jack

Depends on the breaker as to how fast it trips. There are different
"curves" for breakers. I think most home ones are Curve "C".