New Dewalt trips breaker alot

I would simply put a 30 amp breaker in the box but the circuit and plug is only rated for 20 amps. Again the wiring is 12ga 2 + ground about 10 feet from the breaker box.

Also, before I bought this saw, several people on this forum told me either the saw was not 5.5 hp OR it pulled more than the advertised 15amps. I believe it's every bit of 5hp because the first Dewalt I bought was 3.5 hp and wasn't very stout, and it was also rated for 15 amps.

Any suggestions?

Have you checked the voltage at the outlet? It should be 120-122 nominally. You might also check the voltage while starting the saw. As was pointed out ealrlier your saw uses power or wattage which is E X I (volts X amps) and when it doesn't get the volts it needs it will take some extra amps-- also you said it seemed to not like being loaded which usually is another voltage problem indicator. Think about the length of conductor and also any possible connection problems that could exist.

The voltage is a steady 120.1 vac and drops less than a volt or two when the trigger is pulled then quickly recovers.

Dewalt emailed me and said they would send me a new style brush that would eliminate this problem. They still have not responded how they get 2 extra HP out of their DW871 (5.4hp) saw while they keep the amp rating at 15 amps and RPM rating the same as their DW870 (3.5 hp) saw at 15 amps and 3450 rpm. Marketing gimmick I believe.

For now, there is a 30 amp breaker installed in place of the 20 amp and she is working fine. Since the wire is in metal conduit, I'm sure the 30 amp breaker will still protect me to a point. Hopefully the brushes will correct the problem, but I somehow don't feel to optimistic...

If you can't get it straightened out with DeWalt, my advice would be a twenty amp time delay fuse. It's code legal and might keep the heat down in your shop.

Borrow an ammeter and see what is draws.

Make sure that nothing else is on this circuit. A 20 ampere breaker is only good for 16 amperes continuous, but will hold greater than that for awhile. I suspect you have something else on the circuit, take it off.

Jerri

I have the exact same thing as you, only mine is a 15 amp Makita. I have the same set up, power-breaker wise, and I trip mine as well. It tends to do it if something else is plugged into the same outlet, or sometimes just on its own. I have had it plugged into 3 different outlets, from 2 different shops, and a Miller welder generator, and what I find, is that if I am loading up the motor too much, by pushing down to hard and cutting too fast, this is what trips the breaker. Since I've taken it easier, I haven't had that problem. By the way, if you go to your local electric motor rebuilder guy, he will tell you that most of your big companies..... ..dewalt, makita, millwaukee and such, are using the same electric motor from the same company. Supposedly that is the truth as to what I was told.

Branden

anyway, by code, #12 ain't adequate for 30A, you need #10, or so the obelisk says, unless other wise specified elsewhere in the code, or if i am not too confused you can run 30 amps through the #12, but you have to have a 20 amp breaker??? glad i didn't decide to be an electrician when i growed up
rob

http://www.elec-toolbox.com/calculators/voltdrop.htm

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