Table Saw Power Cord...

[Greg Cuetara]

I am in the process of finally getting back to my workshop after over a year away. Starting on some small projects right now. Last night I was cross-cutting some hard maple and mahogany when my Table Saw ground to a halt and I hit the switch almost immediately. This happened twice.

To give a little background I have a Rigid Granite Top table saw and it has served me well over the past few years. I believe that it is 1.75hp and on the tag it says 13/6.7A which I assume to be 13A at startup and then 6.7A when running but I could be wrong. I have 12-2 wiring in the basement on a dedicated 20A circuit and typically only use one tool at a time.

I have my TS in the middle of the room and can not reach an outlet so I have used a heavy duty air conditioner extension cord and again it has worked well until last night. When I went to unplug the saw, which I do because I do not leave it plugged in, one of the prongs was fried. The ground and one prong look like they have not been touched but the other prong was black and the extension cord was burnt also.
The existing power cord is 14AWG from the switch to the plug.

If you have made it this far I appreciate it because here comes the questions. Can I use it as it and just clean off the prong? Should I replace just the plug? The whole cord from the switch? I purchased a 14 GA replacement power cord from the BORG which is 9 feet long. The original was 8 feet long. Can I cut back the existing cord a few feet and then splice in the new cord so that I can run all the way to an outlet rather than use an extension cord? Should I try to get a 12 GA or 10 GA cord which is longer and replace that from the switch?

I do have an 8 GA or 10 GA extension cord that I can use but again would rather not use an extension cord if I don't have to.

Thanks for listening and any advice you can give.

Greg

[Art Mann]

First, the 13 and 6.7 amp ratings refer to 120VAC and 240 VAC operation, respectively. With that in mind, a 14 AWG wire is an adequate extension cord if you keep it fairly short. I am not exactly sure which prong or prongs were burned, (extension cord or the saw plug ?) but I would replace both the plug and receptacle where the burn damage occurred. Whatever caused the burn in the first place will not be fixed by cleaning. I am not sure I would trust the original extension cord at all based on your description.

[Jerry Miner]

Greg--- I am not an electrician, but I have over 50 years of experience with power tools.

Your 13/6.7A motor draws +/- 13 amps when wired for 110 volts, or +/- 6.7 amps when wired for 220 volts. (amps x volts = watts, the real power draw of your motor)

If the prong is fried, but the wires are not toasted, it sounds like you just had a less-than-perfect connection at the plug, causing arcing. IIWM, I would replace the power cord with a 12-gauge cord long enough (but not overly long) to reach the power source without an additional extension cord. The fewer "weak spots" the better.

[Bill Orbine]

13/6.7 means the amps but at different volts 13amps is at lower voltage (110-120 volts) and 6.7 amps is what some call two phase (220-240 volts..... that is two lower volt feeds from panel. The motor tag should show the volt requirements. So, after having read your post, it seems you need a qualified technician to look into your problem since you assumed the 13/6.7 wrong.

[Myk Rian]

If the prong is fried, but the wires are not toasted, it sounds like you just had a less-than-perfect connection at the plug, causing arcing. IIWM, I would replace the power cord with a 12-gauge cord long enough (but not overly long) to reach the power source without an additional extension cord. The fewer "weak spots" the better.
^^^^THIS^^^^ Plus replace the wall outlet. Make the power cord 12 feet @ 12 gauge.

[Dave Zellers]

Many others here are much more knowledgable about electric matters than me, and I'm sure they will be weighing in on this, but my 2 cents is to not use any extension cord less than 12/2 with that saw.

And for heaven's sake, throw away your fried cord.

It IS very odd that you have used your configuration for some time and then all of a sudden it failed.

[Greg Cuetara]

thanks for the input. guess i will go out and try to find a piece of 12' 12ga cord to make a new power cord.

Greg

[Don Jarvie]

Home Depot sells cord by the ft. Buy SGOT (it's a rubber cord) and enough of it to reach the wall. Also buy a new plug and outlet rated for 20 amps. Go with 12/2 which should have 3 wires. You don't say if your running the saw on 120 or 240 but my guess is 120 from your post.

instead of splicing the line replace the line at the motor. Open the cover where the line goes into the motor and swap out each line. Put on the new plug and replace the outlet and you should be good to go.

[Tom M King]

Get a good quality Hubbell plug for the end. The wire will be standed in the SO (other letters will probably be mixed with the S and O somehow for what you find). Buy some rosin core solder. After you strip the end of each wire, solder the bare end so that you now have a hard end, and not a bunch of little wires. These ends will be a more longer lasting connection in the quality plug. When tightening the lugs in the plug, finish with the largest size straight slot screwdriver, so you can get good torque on the screw. I have extension cords I made up like this 35 years ago that still get drug around and used every day now. I do the same when a plug needs replacing on a tool, or trailer wire. I never remember having to go back and redo one.

Take time to be meticulous on getting the end of the wire stripped neatly, with maximum contact in the lug, and minimum left over without cover over the insulated conductors.

[Mike Cutler]

Greg

Can you reuse what you have?

Probably, but only if you find out why you had the problem . It sound like you have a short in that extension cord, or a pinhole in the insulation and outer jacket of the hot conductor.

Should you go back to the switch?

Yes, this is the most correct thing to do. However, the length of 14awg that was supplied with the saw is probably the maximum length capable of carrying that current for that gauge wire. In the owners manual it probably specifies to either not use an extension cord, or use at least a 12 gauge extension cord. Wire in 12 wag or larger and you'll be set. You can save yourself the hassle of making the plug end by just buying a 12awg extension cord in the length you need, with molded plugs, and cutting off the female end and wire it to your switch, or use the wire you have.

Can you splice it?

Yes it can be spliced, but it will take a "gas free", insulated butt splice, which requires a very special tool. Not cheap. If you go cheap you have the potential for hot spots at the splices.

[Erik Loza]

Get a good quality Hubbell plug for the end...

+1 for Hubbell (aka "Twist-Lock"). They are the industry standard for industrial machinery that requires a plug. You can get them at Lowes/HD....

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Best of luck with it,

Erik Loza
Minimax USA

[Doug Richardson]

If I were you Greg, to be safe I would just rewire the whole damn house..... :rolleyes:

Seriously tho, if you always use the table saw in approximately the same position, why not just put a longer cord on the saw, and replace the outlet and plug with a "Twist-Lock" like others have recommended. That eliminates one future high resistance connection that could happen again.....

By the way, I "was" an electrician, until I got a comfy "sit on your ass" job.....:o

[Greg Cuetara]

I ended up buying 12' of 12ga wire from the BORG with with a plug and rewired the TS all the way back to the switch. Everything seems to be working well right now and no need for an extension cord. I ran the saw for about 2 hours last night ripping some boards and didn't have any problems. Not sure if I want to try and rewire from the motor to the switch just yet but that may be a project for another day.

Greg

[Dave Richards]

Greg, I work on medical equipment and electrical safety is a huge concern in this business. I've carried some of the procedures I use at work into my shop. I have a few pieces of equipment with cord caps that I've installed myself. From experience at work, I know that the screws in those plugs sometimes work loose with time so I check them periodically. The simple check is to shake the plug. If the screws are tight, the plug won't rattle. Generally I prefer to use molded plugs on cords and in cases where I need to replace or add a cord, I will usually buy an orange heavy duty extension cord and cut it to length leaving the plug intact. It's usually less expensive than buying power cable and the caps to go on the ends. Nearly everything we have now at work uses the Euro style power cords with molded plugs (similar to computer power cords). If we don't use a molded plug on the cord, we use a Hubbellock explosion proof twist locks.

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Another check I perform periodically on my tablesaw, bandsaw and other 3 wire tools is to check ground integrity. I measure between the ground pin on the cord and the table top as well as other bare metal points I might touch. I look for less than 0.5 Ohms of resistance. That's the limit allowed for medical equipment and it works for me in the shop. I also look for infinite resistance from the hot side pin to the saw when the switch is turned off.

Disconnecting the power from the saw is a good idea but unplugging and plugging in the power cord--even with a twist lock plug--can cause wear and tear. Springs in the receptacle can loosen and result in poor connections, increased resistance and a greater chance of fire. I added a service disconnect box on my tablesaw. It is positioned so I don't have to walk away from the saw to disconnect power. I can pull the plug thing out and lay it on the saw table and see that there's no power to the saw. I can also remove the thing and lock it away or just turn it over in the box and lock the box if I want to ensure the saw can't be run when I'm not there. the service disconnect is really intended for 220 service but my saw is set up for 120V. I ran the hot and the neutral through the removable insert in the box and made sure the ground carried through around it. It's very useful and a lot more convenient that walking over to the wall to un plug the saw.

[Peter Quinn]

I know this is a done deal, for posterity I'd suggest NEVER operating stationary power equipment on ANY extension cord. Even one which is properly size is to me dubious. Each set of plug and sockets adds a little resistance and makes heat. You've seen the results of excessive heat. And rather than repeatedly plugging and unplugging a machine install a knife kill switch, with a lock if necessary to keep out children, neighbors, BiL's, whatever you might need to protect against. It's no surprise to me that this took years to present itself, my guess is it's the cumulative effect of heat and wear finally resulted in a failure and luckily not a fire. My Dad was an electrician, used to do small jobs, I saw some of the dumbest stuff ever run on extension cords, we were usually called just after a small fire or somebody had a plug fry. We put plugs closer to the end use location, it's amazing how much more current a solid strand AWG wire can handle than a multi strand extension cord long term.

[Mike Cutler]

I ended up buying 12' of 12ga wire from the BORG with with a plug and rewired the TS all the way back to the switch. Everything seems to be working well right now and no need for an extension cord. I ran the saw for about 2 hours last night ripping some boards and didn't have any problems. Not sure if I want to try and rewire from the motor to the switch just yet but that may be a project for another day.

Greg

Greg

You shouldn't need to rewire from the switch to the motor. I am assuming it came prewired. The wiring from the manufacturer is just fine.
That 12AWG cord will carry more current than your saw is capable of using. It will last you the life of that saw and beyond easily.

[Alan Gan]

I would just add as a simple test, grab the cord close to the Plug and see if it feels warm/Hot. If it feels unusually Hot I would say there may be something up with the motor or connection... JMHO