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Thread: Table saws with soft start - recommendations

  1. #1

    Table saws with soft start - recommendations

    I'm in the market for a table saw, but it needs soft start - my AFCI breakers tend to trip on tools without it. Unfortunately, that rules out a lot of options (like DeWalt and SawStop). I've looked at the Bosch 4100XC, but it has mixed reviews. Does anyone have a recommendation for something reliable (and available in Canada)? I would prefer to stay below $1000 CAD for a portable saw, although I'd consider going up to $2000 for a stationary saw.

  2. #2
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    Aren't you allowed to just go up a size if the breaker trips? Seems like you'd be narrowing down your options by requiring a soft start for any decent sized motor.

  3. #3
    It's not the current per se – rather it seems to be the inrush current when turned on that trips AFCI.

  4. #4
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    Quote Originally Posted by Greg Funk View Post
    Aren't you allowed to just go up a size if the breaker trips? Seems like you'd be narrowing down your options by requiring a soft start for any decent sized motor.
    Only on a dedicated circuit.

  5. #5
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    My company builds houses, we deal with AFCI breakers and tools a lot. I don't think soft start is going to fix it for you. Any motor with brushes is going to cause trouble, the bigger the motor the worse it gets. Some brushless tools and even battery chargers will also cause them to trip non-stop. We keep a few non-AFCI breakers in the trucks to use while we're there and switch back to the AFCI after we're done. AFCI technology is not ready for prime time in my opinion, I think the NEC jumped the gun on changing the code too soon. Also see them causing problems with older appliances.

  6. #6
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    My understanding is that AFCI breakers react to motors with brushes. Most motors on table saws don't have brushes. The other option is to determine if AFCI breakers are required on the circuits in your shop.
    Lee Schierer
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  7. #7
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    Gert a used saw with a three phase motor and run it from a vfd. Adjust the acceleration time so it does not trip. A vfd will also have some small amount of load reactor built in to reduce EMF into the mains wiring.
    Another choice would be to install a load reactor on the input to the saw. I think that would reduce the input rush enough. Buy a used three phase one on the bay and only wire up two phases.
    A line reactor and a load reactor are different terms for what are essentially the same thing just depends on if it is installed before or after the switch. They will also help protect from surges either into or out of the equipment.
    Bill D
    Last edited by Bill Dufour; 08-12-2022 at 10:04 AM.

  8. #8
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    Quote Originally Posted by Lee Schierer View Post
    Most motors on table saws don't have brushes.
    That may not be true for the portables that the OP is considering, at least yet. Cordless tools have very much gone that route, however.

    ----

    OP, that brings up something to consider. There are several cordless portable table saws available now that offer pretty darn good performance, based on what I've seen from builders like RR Buildings using them on the 'Tube. You'd be able to bypass the whole AFCI thing that way. There may be an initial cost of entry if you don't already use the battery system for the saw you choose, but it's certainly worth considering.
    --

    The most expensive tool is the one you buy "cheaply" and often...

  9. #9
    My electrician who is also a cabinet maker was able to get the electrical inspector to agree to conventional breakers for the 220 v circuits for stationary power tools. It has certainly made my shop trouble free from false trips.

  10. #10
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    Quote Originally Posted by Tyler Bancroft View Post
    I'm in the market for a table saw, but it needs soft start - my AFCI breakers tend to trip on tools without it. Unfortunately, that rules out a lot of options (like DeWalt and SawStop). I've looked at the Bosch 4100XC, but it has mixed reviews. Does anyone have a recommendation for something reliable (and available in Canada)? I would prefer to stay below $1000 CAD for a portable saw, although I'd consider going up to $2000 for a stationary saw.
    They trip even with soft start. I can't run a track saw on a AFCI without it tripping.

  11. #11
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    Quote Originally Posted by Lee Schierer View Post
    My understanding is that AFCI breakers react to motors with brushes. Most motors on table saws don't have brushes. The other option is to determine if AFCI breakers are required on the circuits in your shop.
    Here, here. The NEC is open to interpretation in many cases, severely strict in others. I got my shop built prior to the AFCI requirement. My GFCI's have been fine with all machines but, there was no requirement for 240v GFCI during my build window. I'll assume this shop has been added within the last year and will be inspected. If the AFCI's cannot function in the role designated you can contest them. If you are not struggling to pass an inspection I would replace or upgrade them to something that works. I would not choose my tools to appease a finicky circuit breaker.
    "A hen is only an egg's way of making another egg".


    – Samuel Butler

  12. #12
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    Quote Originally Posted by Tyler Bancroft View Post
    I'm in the market for a table saw, but it needs soft start - my AFCI breakers tend to trip on tools without it. Unfortunately, that rules out a lot of options (like DeWalt and SawStop). I've looked at the Bosch 4100XC, but it has mixed reviews. Does anyone have a recommendation for something reliable (and available in Canada)? I would prefer to stay below $1000 CAD for a portable saw, although I'd consider going up to $2000 for a stationary saw.
    The issue with portable tools is that are wound rotor motors with brushes.

    It is the arcing at the brush/commutator that produces the high frequency waveforms that the AFCI breakers respond to, it is not an inrush current issue.

    Talk to the local inspector, they may agree to allow GFCI on a circuit only used for portable power tools……Regards, Rod

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