Chop Saws

Well...thats 20-22volts drop...so thats up to 22x15amp=330 watts of heat!

I think 5-10 volts is max on a 120 outlet depending on who you ask. The older motor might have drawn less power, had internal differences, etc and been less sensitive to the heat.
 
I always try to stay within 3% of no load voltage. Don't know why or where I read that, code book or not, but that is my rule most of the time. If no load is 120VAC, then anything below 116 could be damaging the saw.

If saw is pulling 10 amps at 100 feet from a 120V source, #12 copper should limit the voltage drop to 2.90%.

#10 copper will put you at 2.1% drop.

Here you go:

electrician2.com voltage drop calculator
 
3% is code, from panel to panel with no more than 5% from the service entrance to the last point if I recall correctly.
 
cquestad said:
Well...thats 20-22volts drop...so thats up to 22x15amp=330 watts of heat!

I think 5-10 volts is max on a 120 outlet depending on who you ask. The older motor might have drawn less power, had internal differences, etc and been less sensitive to the heat.
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You should stick to Mechanical stuff. :)

Your calculation is showing what is being dropped in the wire as heat assuming that all of the voltage is being dropped in the conductors as well.

110-120V is the rating on most.

100feet is too much, because you need to double it because the return path. So you have 200 feet of conductor+ the double the length of the cord as well.

I don't have my NEC book with me to actually get the impedance value/foot of the 12 gage wire. However the next step would be to measure the voltage at the panel when your running the saw as well.

However 96V at the outlet is too low.

Say 115/96 is 1.2. To make the saw do the same work your drawing 20% more current. And we know that current^2*resistance is the power(so your actually putting more heat into the motor to the 2nd power).
Enough rambling.

Measure a few points along the way for the drop and see if you have an issue with a bad connection etc. If you don't find one, and the voltage at the panel isn't dropping much, I would say your best bet is to run a #10 to the saw outlet, or move the saw.:)


Is this a sub panel, or tail panel off of another service? If so if those conductors are not very large either, you need to figure those as well.
 
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4x4dually said:
Glad someone remembers the NEC book content. :hehe: That book is from the "debil, Bobby Buchea".
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That calculator is pretty neat that you found. It seems that those drops are kind of conservative though. I guess he is assuming an infinite buss with no voltage drop at the panel, etc.

Had several interesting situations pop up at my previous employer with voltage drop. Some guys tried to do the right thing by having no terminations in the ceiling and terminating everything at the floor. Problem was the ceiling was 30 feet high, and there were about 10 outlets on each circuit. So you can imagine the drop you would see. Went around the building with a voltmeter and a industrial hair dryer as the wrote the voltages on the print. I could sketch the run by the systematic drop at each outlet as you went further away. Down to 89V at the end. They got to repull the wire with #10 and the lowest drop at that point was 10V(120V supply)
 
crackerman said:
Spend the money on either a cold saw, or a lay down band saw, cuts almost as fast, less mess, less fire hazard and no burrs to grind off
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Any recommendations for a good cold saw that won't put me in the poor house? I'd love to have a Dake or Baileigh but I can't justify the expense.

DuramaxPowered said:
I purchased an Evolution Rage II chop saw. It has a toothed blade, instead of abrasive. It cuts excellent IMO. I would recommend it to any hobbyist.
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Is that the 14" saw? If so, mind if I ask how much?
 
Thats the way to do it...buy a nice "wood" compound miter or just miter chop saw and run metal blades. IMHO the red Diablo blades are the best.
 
Always wear eye protection if you use a carbide blade in a skilsaw. Kinda forgot the warning label. Those bits hurt.
 
Put in another outlet just for the chop saw. Pretty sure it's #10 wire, about 100' from the box.

Holy smokes, it's a whole different machine now.
 
Timbeaux38 said:
This thread got nerdy quick.....
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It sure did. I was just gonna say get rid of the chop saw and get a band saw. I havent used my chop saw in years since I got a portable band saw and my not so portable Carolina band saw. Thought about selling it.. Its a Dewalt.
 
I've got a band saw that I need to fix. I forget the brand, but parts have been tough to find. I let my old man use it once and he had one of the blade guides busted off. I never actually did get to use it. :doh:
 
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