On Thu, 21 Feb 2008 04:48:18 GMT, Robert Allison
wrote:
Howard wrote:
On Feb 20, 8:59 am, Robert Allison wrote:
Airedale wrote:
I am picking up a Table Saw and it comes prewired for 110, but have
been told it can be switched over to 220.
Right now I do not have a 220 line in the Garage, but am thinking of
having an electrician come out to put in the line. Is it worth it?
What are the benefits of going 220?
I probably need a line run anyway as I keep tripping the circuit
breaker with a few things running at the same time.
Thanks,
Adam
You have alot of pretty good suggestions about the subpanel,
etc., but I don't think anyone has yet answered your original
question.
The basic reason for running 220 volt vs 110 volts would be to
decrease the amperage load. For example: If you were running a
tool that draws close to 10 or 12 amps on normal run time, the
amperage would increase on start-up (initial load/torque) and if
the tool was put under a heavy load (like ripping on table saw or
taking the maximum cut on a planer) the amperage would also
increase, relative to the load placed on the tool. If plugged
into a standard 15 amp line, you'd most likely trip the breaker.
But even if not, you'd be pulling enough amps through the
standard 14 guage wire as to risk overheating it. (14 guage wire
is rated for 15 amps and 12 guage wire is rated at 20 amps.) You
must also have the proper receptacle for whatever you are going
to use... 110 volt/15 amp, 110 volt/20 amp, 220 volt, etc.)
Basic electricity (Ohm's Law) dictates that as voltage capacity
increases, the amperage decreases. So, a 15 amp load at 110 volts
would decrease by half at 220 volts... which would be 7.5 amps.
I run mine on 220, but I really can't tell much difference in the
performance of the saw. I have had it wired both ways, and it
doesn't seem to change the power of the saw. (Of course, I would
have to have two identical saws and try them side by side with
the different voltages to really compare.)
--
Robert Allison
Rimshot, Inc.
Georgetown, TX
Wow I dont know what saw you are runing but I went from a 110 delta
contractors saw to a 220 volt delta unisaw. It is like night and day.
When you turn it on you can feel and hear the difference. Push a board
throught and you will never go back to a 110 saw. I go out of my way
to obtain all 220 tools.
I am comparing the SAME saw on 110 and 220. I don't notice much
difference. I notice alot of difference between different saws,
but I don't notice much difference in the same one. And it is
running on 220.
The whole key to this is what the supply is like. If you have a good
stiff 120V supply with a short cord, you likely would see zero
difference between 120V and 240V wiring. Once the voltage gets to the
motor the motor cannot tell whether it's 120V or 240V, anyway. The
voltage goes through the same windings (just differently) Each winding
sees exactly 120V regardless of how the motor is hooked up.
However, the wires outside the motor are all the difference. If your
120V supply is a long way from the panel and you have a long motor
cord, and god forbid it's a 15A circuit, your saw is going to jump to
life like a racehorse out of the gate when it's wired (and supplied)
for 240V.
It is not, however, because there's something magic about 240V or the
motor. It's about double the current draw at 120V and four X the
percentage of voltage drop that makes the difference.
And there're no heat issues, no energy savings, no magic pill. Stiff
supply, no difference. Long runs, 240V usually makes a difference.
--
LRod
Master Woodbutcher and seasoned termite
Shamelessly whoring my website since 1999
http://www.woodbutcher.net
http://www.normstools.com
Proud participant of rec.woodworking since February, 1997
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