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Extension cord for 15 amp saw

50K views 40 replies 19 participants last post by  Speedy Petey  
#1 ·
What happens when you use an extension cord that isn't rated high enough for the tool?

For last few days I've been using a medium duty 50' chord for my Sliding Mitre, (Makita 15 amp). Am I damaging the motor? Am I getting less power than I would with a proper cord, (it feels like it)?

What should I buy?
 
#2 ·
#4 ·
Well, you saw is worth several hundred dollars and when it does not work it is worth thousands for the amount of work you cannot do, I notice most uneducated trades pick up the 100' cord from HD for $ 29.00 and expect to use it on their expensive tools. You bought a good tool, buy a good cord, HD doesn't sell them either you need to purchase from a proper supplier or ask and electrician friend to size it properly and get you wire and male/female ends and make it up for you.
 
#6 ·
bottom line is you have voltage drop creating higher current, do what the other guys said and use a heavy duty size conductor (like 12-3 SJ or SO extra hard use cord) approved male and female ends with strain releif... those other cheap cords are for small loads like charging yer batteries for tools and maybe a drop light or somethin........
 
#8 · (Edited)
What happens when you use an extension cord that isn't rated high enough for the tool?

For last few days I've been using a medium duty 50' chord for my Sliding Mitre, (Makita 15 amp). Am I damaging the motor? Am I getting less power than I would with a proper cord, (it feels like it)?

What should I buy?
Yes to both. Using a cord that is undersize and delivers inadequate power to a tool will shorten the motor life. This is even more so on something like a miter saw that has such frequent starts. Do not waste money on anything less than a quality 12ga cord. The key word here is quality, which is directly related to the price. The cheaper cords are cheaper because they have garbage for plugs on them, and they will need to be cut off within three months. Spend $10 to $12 for replacement ends of the cord and you are at or more than the price of buying the better cord to begin with. The outer sheath of the better cord is also a better quality material and will last much longer before it splits. I do use a couple of contractor grade, 14 ga, 15' cords for "bench" cords, plugged into a multi-tap at job work table for sanders, routers, etc.
 
#9 ·
I will tell you what you want. A drop cord that has the metal box you plug into.. You know has the metal box that has a couple of plugs in it. You use to be able to buy those from a place that sold stuff to auto mechanics. Same goes for those good light bulbs that if you bang them around they won't blow.I would imagine a sparky could make a few of those in no time at all.
 
#10 ·
That sounds like what I use for my "main" cord to the power source. I used to do marine work, so I had access to 10/3 shore power supply cords for boats when the plugs got damaged. You have to search to find a 15 amp male plug that will accept 10 ga wire, but they make them. On the other end I put an aluminum 4x4 outdoor box with two top quality duplex receptacles. Been using this same cord for twenty years, replaced the male plug once, and the receps a couple of times, but the cord will probably outlast me. The
 
#14 ·
I've had good luck with the "Yellow Jacket" cords that I purchased at the HD. I also tried some knock offs that look the same and had the ends burn up on me.
Yes, they do make a good cord. I think most of mine are Yellow Jacket now. Leviton makes some nice cords too. I try to get the "main cords" in 10 gauge, and the shorter "branch cords" in 12 gauge. The 14 and 16 gauge cords are for Christmas lights, and have no place on the jobsite.
 
#17 ·
Well what do you know, the saw is back to functioning like normal. ALL my corded tools are working better actually.

Lesson learned. Thanks for the advice.
Yeah, don't skimp on the cords. It confounds me why a guy would run his many hundred dollar miter saw, for instance, on cords from the discount store. #10 for your 100 footers, and #12 for everything else.

Keep in mind that it's technically "illegal" to plug one cord into another to make one long run.
 
#21 ·
I don't have a use for 100 foot cords in what we do. I bought a 100' heavy gauge cord and cut it up into five 20 footers and put metal plugs on them. This thread reminds me I probably could use another 100 footer to cut up into some more shorties.
 
#28 ·
The run to the receptacle I'm using using is probably 40' from the panel. And then I plug my cord it into a power bar.

Does the length of the run to the receptacle from the panel affect what kind of power I'm getting?

Does the power bar make tools more succeptable to bogging down under load?
 
#29 ·
Does the power bar make tools more succeptable to bogging down under load?
You're technically not allowed to plug an extension cord into a power strip or one power strip into another power strip. The actual cords off the tools or appliances are the only things permitted to plug into a power strip.

But the answers to your questions are normally 'yes' and 'yes'.
 
#32 ·
How about a 1900 box(I think it's called a 4 x4 box), a cord grip and 2 duplex receptacles, that will give you 4, you could use 1 single and 1 duplex for 3. Dip the outside of the box in that liquid rubber (tool grip in a can) so it doesn't scratch surfaces. I'd post a picture of mine but I don't wan't MD to see it (it's bad).
 
#34 ·
I was hoping for something more like this set up

Image


I'd like to put that on maybe 2-3 of our custom 25 foot cords. Right now we plug in one of those little shorty GFCI 3 ways like these into a longer cord and then split of that when we pull power usually out in the garage to set up cutting stations and such.


Image


But I'd like to just get it all hardwired into the extension cords.

The duplex box would work, but it would be too bulky on a bunch of cords and a detachable set up is pretty much the same as the picture above.
 
#37 ·