It's a 10 inch Ridgid wet tile saw from home depot. I have a dimmer light switch, and I was hoping to use it to slow the saw down about half the regular speed.

Would doing this damage the motor or anything?

  • \$\begingroup\$ You need an induction motor controller for 1.5 HP but these tend to have poor speed load regulation so that’s why they invented VFD’s \$\endgroup\$ Oct 7, 2018 at 3:52
  • 1
    \$\begingroup\$ Why would you want to reduce blade speed? Greater velocity should improve cuts for diamond or carbide abrasive blades. \$\endgroup\$
    – K H
    Oct 7, 2018 at 3:56
  • 2
    \$\begingroup\$ Reducing the cutting torque of any saw is NOT a good idea. They have a high-torque motor so they will cut instead of jam to a stop, which can blow a fuse or trip a breaker. \$\endgroup\$
    – user105652
    Oct 7, 2018 at 4:45

2 Answers 2


Most dimmer switches are rated 500 watts max and a 10" tile saw might be 1500 watts. The nominal current consumption of the motor is already three times the maximum of the dimmmer switch. Worst is the starting current of the motor can spike even 10 folds of the nominal. This will instantly destroy the triac in your dimmer switch.

Additional to this, motors are inductive loads which cause lots of problem with phase controlled lamp dimmers which are plainly made for the resistive load.

You probably have to look for higher power phase controlled chopper designed specifically for universal motors.


Light dimmers are not meant to be used with inductive loads like motors. You will destroy it pretty quickly. You can buy dimmer/speed controllers that are meant for use with motors.

The tile saw is almost certainly a series-wound motor which will work just fine with a triac speed controller.

  • \$\begingroup\$ The motor speed controllers that you mention can often be found in hardware stores as controllers for ceiling fans. \$\endgroup\$
    – DrSheldon
    Oct 7, 2018 at 7:25
  • \$\begingroup\$ I doubt that such meet the power specs needed to regulate a load of 800 W or more. \$\endgroup\$
    – dlatikay
    Oct 7, 2018 at 8:43
  • \$\begingroup\$ @DrSheldon I was talking about one of these: amazon.com/Power-Speed-Controller-Router-Motors/dp/B0012WKCXK \$\endgroup\$
    – τεκ
    Oct 7, 2018 at 13:32
  • \$\begingroup\$ @dlatikay: I bought a 1000 W fan controller several years ago; they do exist. However, most on the market are only 500 W. \$\endgroup\$
    – DrSheldon
    Oct 7, 2018 at 15:29

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