Power switch and other problems

[eddie357]

i currently have the bt3100 saw bought it new a few years ago, well lately i noticed my switch would stay in the on position well just the other day i was working and smelled smoke looked down and saw smoke coming from the switch, needed to finish the task so i just rewired it the switch to a power strip but now i noticed that my saw bogs down really bad just cutting small pieces of wood, what could be the problem any help would be greatly appreciated.

[mpc]

Too-small extension cords (too narrow a wire gauge) and/or too long an extension cord leads to excessive resistance in the extension cord, denying the motor the energy it needs to run properly. Most power strips are not intended for table-saw style amperage; I wouldn't be surprised if you're overloading a typical "PC power strip" type of strip... it's acting like an extension cord made of skinny wire. Probably getting warm inside!

mpc

[cabinetman]

Too-small extension cords (too narrow a wire gauge) and/or too long an extension cord leads to excessive resistance in the extension cord, denying the motor the energy it needs to run properly. Most power strips are not intended for table-saw style amperage; I wouldn't be surprised if you're overloading a typical "PC power strip" type of strip... it's acting like an extension cord made of skinny wire. Probably getting warm inside!

mpc

That's a good possibility. It would also matter if you had other items powered off the same power strip.

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[cork58]

I would suggest you fix the power problem then e-mail Ryobi and they will send you a new switch at no cost to you. I have 2 saws and just got around to getting the new switchs. Good excuse for putting it on the left side too.

[dbhost]

These folks are right. Too thin a guage of extension cord feeding a 15 amp saw can have disasterous results for both the saw, and potentially the building it is in. That wire can and often does get hot, which can cause a fire. If all you smoked was the switch, you go off lucky. Replace the switch with a proper one, and do NOT run that saw with any cord smaller than 12 gauge. Power strips typically have 16 guage cords. Fine for stereos or PCs, but dangerous for table saws and dust collectors...

[Kristofor]

These folks are right. Too thin a guage of extension cord feeding a 15 amp saw can have disasterous results for both the saw, and potentially the building it is in. That wire can and often does get hot, which can cause a fire. If all you smoked was the switch, you go off lucky. Replace the switch with a proper one, and do NOT run that saw with any cord smaller than 12 gauge. Power strips typically have 16 guage cords. Fine for stereos or PCs, but dangerous for table saws and dust collectors...

It certainly won't hurt (will help if minimally) to use a 12 guage extension cord, but there's a good chance the wiring in the wall is smaller than that (14), so if you're talking about another 6 - 20 feet at 14 guage it isn't going to make a big difference. Heck even 10 feet (x2 for return path) of 16 guage is only dropping your voltage by ~1.2 volts. That's not a good thing, and perhaps should be avoided but isn't likely to cause a fire or trash your saw on its own (there's more variation than that in the power supply around the country and even from one location in your house to another already).

That said, the comments about many power strips being rated for less than a 15amp saw load are true, and there may be internal components with even more resistance than 16 gauge wire causing a further voltage drop. Try a decent gauge, short length, extention cord directly and you can determine if that's your problem.

Oh, also, I assumed by reading your post that you took the switch out of the circuit but wasn't 100% certain. If that's still in there somewhere the fused contact points can be a source of significant resistance and voltage drop as well.

[woodturner]

It certainly won't hurt (will help if minimally) to use a 12 guage extension cord, but there's a good chance the wiring in the wall is smaller than that (14), so if you're talking about another 6 - 20 feet at 14 guage it isn't going to make a big difference.

Receptacles should be wired with 12 gauge per NEC. Of course, that doesn't mean they are....

[LCHIEN]

i kind of held off answering this because I think you have at least two problems.

Your first problem is that you have a 3100 with the known bad switch design, you can get an improved replacement by calling the Ryobi 800 number and asking for it. That's the sticking on problem.

You also appear to have a problem causing the smoke. If the switch really was the thing smoking then it may simply have had high resistance in the contacts that got stuck together. I hope that's what it is but your last statement worries me that your motor is damaged. You don't say what you were doing before that, e.g. cutting a lot of hard or thick wood and overloading the saw or what?? It really doesn't make any sense that alone, a bad switch would cause the motor to run poorly after bypassing the switch. Unless you damaged the motor at the same time you smoked the switch.

[Kristofor]

Receptacles should be wired with 12 gauge per NEC. Of course, that doesn't mean they are....

The vast majority of general use (non-kitchen) circuits in houses and apartments I've lived in were 15A rather than 20A, and of those the vast majority were wired with 14 gauge wire. That may have changed to be prohibited for new construction (or I've had the bad luck to live in lots of non-compliant locations) but my (admittedly limited) sample leads me to believe that it's a good chance that that's what's feeding any randomly selected receptacle he may have been using.

[dbhost]

Not sure about other areas, but around here, minimum wire size allowable for any receptacle is 12ga, even with a 15a outlet... Has been that way from what I understand since at least the 70s. Not too many homes around here older than about 1972 anyway... The older stuff got blown away by hurricanes...

[cabinetman]

The vast majority of general use (non-kitchen) circuits in houses and apartments I've lived in were 15A rather than 20A, and of those the vast majority were wired with 14 gauge wire. That may have changed to be prohibited for new construction (or I've had the bad luck to live in lots of non-compliant locations) but my (admittedly limited) sample leads me to believe that it's a good chance that that's what's feeding any randomly selected receptacle he may have been using.

I find that in older homes when doing installations, still on 15A. Around here there are a lot of older homes.

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[eddie357]

i thank everyone for the quick replies, as suggested i got rid of the power strip wired a 15a switch (wall) into the circuit and was still getting the motor bogging down, so i just replaced the blade with a 7-1/4" blade and i dont seem to have any issues, but using a standard 10" blade it bogs down really bad, and this was a new blade i was using.

[eddie357]

i was ripping down some 2x6 construction lumber when the switch started smoking, i had been having some problems with the switch sticking prior to going out.

[LCHIEN]

you're not going to want to hear this but my theory is that you smoked the motor by overheating it when doing the rips.

Long rips can be done with the saw. But best to do with some time in between to cool. Pine can be tough because of pitch and knots. I don;t know how many you did but doing a lot of them back to back can really tax the motor - cause it to overheat and damage the windings leading to loss of power... worse if the motor is on a undersize extension cord, worse if the switch is lossy (but we don't know for sure), worse if you don't use an efficient ripping blade. Those last 3 conditions lead to lower voltage, and more current which causes extra heat. One of the weaknesses of the BT is lack of a thermal cutout.

[cabinetman]

i thank everyone for the quick replies, as suggested i got rid of the power strip wired a 15a switch (wall) into the circuit and was still getting the motor bogging down, so i just replaced the blade with a 7-1/4" blade and i dont seem to have any issues, but using a standard 10" blade it bogs down really bad, and this was a new blade i was using.

What was the 10" blade you put on (tooth design and count)?

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