Which Gauge Cable

[tony roth]

I am wondering if I can use 10 gauge cable to attach my bandsaw, 4HP, not 100% certain on the amperage (but i believe 15 amps peak, its on a dedicated 30 amp circuit, 220v), to the outlet, or do i have to use 12?? I already have the 10 and would prefer not to purchase 12 if i don't need to. that said, if 12 will either be safer or give me better performance, i'll go ahead and purchase it. any advice would be greatly appreciated. thx. tony.

[Frank Pellow]

I am wondering if I can use 10 gauge cable to attach my bandsaw, 4HP, not 100% certain on the amperage (but i believe 15 amps peak, its on a dedicated 30 amp circuit, 220v), to the outlet, or do i have to use 12?? I already have the 10 and would prefer not to purchase 12 if i don't need to. that said, if 12 will either be safer or give me better performance, i'll go ahead and purchase it. any advice would be greatly appreciated. thx. tony.
You can use 10 gauge. Just in case you were not aware, 10
gauge is thicker than 12 gauge.

[tony roth]

thanks, no, i know 10 gauge is thicker, but didn't know if i would run into a problem if i were to use something that were "too" thick....

[Lee DeRaud]

Just in case you were not aware, 10 gauge is thicker than 10 gauge.My eyes must be getting old: they looked the same in the store.

[Dan Stuewe]

My eyes must be getting old: they looked the same in the store.

Must be metric

[Norman Hitt]

You can use 10 gauge. Just in case you were not aware, 10 gauge is thicker than 10 gauge.

Frank, I think your fingers got in the reproduction mode while typing. :D

I believe you meant to say that 10 guage is a larger diameter than the 12 guage, and for Tony, the 10 guage is required for a 30 amp circuit, whereas 12 guage is for a 20 amp circuit.

Most likely the 10 guage, (with the appropriate 30 amp recepticle) will handle your 4 hp motor, but you Should look at the amperage printed on the motor to be sure.

If you Should require a heavier wire, (which I doubt), you would need to go to an 8 guage wire, (and again, the appropriately rated recepticle for the required amperage).

Note: on larger hp motors, Ideally, you should use a Motor rated Circuit Breaker in the panel to handle the momentary start up current surge.

[Jeff Fritzson]

You will be better off with 10 guage. You want to make sure that the length of your extension cord is not too long. Preferably less than 25 feet. Although I am no electrician, these are general guidelines you will see printed in several reference books.

If you think of plumbing and electrical similarly you will see that the bigger the wire is analagous to the bigger the pipe. You can hava a lot more water run smoother through 2" pipe than you can through 1" pipe. The same is true for electricity (electrons) through wire. The 12 guage would probably work fine for your partticular application but you will not go wrong with 10 guage.

[tony roth]

Thanks again. Just to be clear, the circuit is 30 amps and i can't recall what gauge the electrician used for the circuit itself. its the power cord from the machine to the circuit that i am asking about. i was told i could probably get a way with a dedicated 20 amp circuit, but in order to be safe and stay within the spec with regard to the start up surge, 30 amp would be better. i was also told i could safely used 12 gauge for the power cord, but i already have a bunch of 10 on hand and didn't know if there was a problem using larger gauge then required. also, in case it matters, this is all single phase. thx. best, tony.

[Chris Padilla]

There is never any harm in using a guage larger than you need...going smaller is the one to be more leery of....

Generally:

#8 is 40 A
#10 is 30 A
#12 is 20 A
#14 is 15 A

So if your 30 A circuit was wired properly, it will be #10 (or larger). Anything smaller and you aren't following code and have a potential dangerous situation on your hands.

Extensions cords should match what is in the wall IMO but that isn't always necessary as you see plenty of #16 extension cords for sale at the store. Most stuff you need extension cords for won't draw more than 10 A anyway so that is why #16 is popular: it is light and cheap.

For a dedicated extension cord that you might have for a large piece of ww'ing machinery, I wouldn't go less than what is in the wall and I'd keep it as short as possible.

[tony roth]

thanks everyone for all the help! 10 it is then.

[Jason Solodow]

Here's a question along the same line. I'm getting ready to hook up my dust collector which has an 18amp 3HP motor, I'm planning on putting it on a dedicated 20amp circuit with 12gauge wire. I saw a reference to a Motor circuit on the panel, should i get one of these for it? Or will the DC starting up not overload it?

[Chris Padilla]

Here's a question along the same line. I'm getting ready to hook up my dust collector which has an 18amp 3HP motor, I'm planning on putting it on a dedicated 20amp circuit with 12gauge wire. I saw a reference to a Motor circuit on the panel, should i get one of these for it? Or will the DC starting up not overload it?

Jason,

You should be just fine with a regular old 20 A breaker or at least, I'd certainly start there. The motor appears to be wired for 120 V, right? Can it be wired for 240 V? More options open up if it can be wired to 240 V.

[Dean Baumgartner]

Note: on larger hp motors, Ideally, you should use a Motor rated Circuit Breaker in the panel to handle the momentary start up current surge.

Square D makes a special HMI rated breaker for the high magnetic influx from starting a large motor. That solved problems I had with my compressor tripping out the 20 amp standard breaker.

[Frank Pellow]

Frank, I think your fingers got in the reproduction mode while typing. :D

I believe you meant to say that 10 guage is a larger diameter than the 12 guage, and for Tony, the 10 guage is required for a 30 amp circuit, whereas 12 guage is for a 20 amp circuit.

...

Right you are Norman. I corrected it.

By the way, I installed 10 gauge wirre throughout my shop for my 240 volt 20 amp circuits. I did this in case I wanted to upgrade any of them to 30 amp in the future. Of course, I am using 20 map circuit breakers right now.

[Chris Padilla]

Right you are Norman. I corrected it.

By the way, I installed 10 gauge wirre throughout my shop for my 240 volt 20 amp circuits. I did this in case I wanted to upgrade any of them to 30 amp in the future. Of course, I am using 20 map circuit breakers right now.

Yep...I even have #10 everywhere in my garage. :)

[Ken Fitzgerald]

Yep...I even have #10 everywhere in my garage. :)
I wired mine 10 gauge also!

[Jimmy Walker]

I also wired my 240 stuff with 10ga.

Tony don't ever worry about "something too thick". If I could afford itand they made 120 recepticles for it, my shop would be completely wired with 8ga. The larger the wire the less voltage drop you will have.
Motor killers are not the work you do, but the voltage it gets when it's working hard. Just use the water hose theroy to understand wiring.