electricalwiring
I have a harbor freight dust collector and want to have 2 switches in different locations of my garage to be able to turn it on from either location. I have 2 Leviton MS302-DS switches that are motor rated. Is there a way to use these switches as 3-way switches? I have included the wiring diagram below. The website for the switch is https://www.leviton.com/en/products/ms302-ds
Since the red wire is already being used for the outlets, you'll need to run a pair of 3 wire cables from the existing switch box to the location in the garage where you want these light switches.
This is what you'll likely have to do:
Here are some other options:
Practically speaking, this arrangement should work without an issue, as everything is on the same circuit and a smart-switch isn't going to draw enough current to significantly heat a metal box by induction. However, there are some very sticky Code-compliance issues involved with funky neutral routing -- the 300.3/300.20 mess is not at all clear, and if you have metal boxes, what you describe is technically a Code violation unless you modify the box to put a slot between the switch-loop cable and the incoming-power cable.
A plastic box, though, is immune to these sorts of issues...but the neutral not being in the same cable as the hot could still be seen as a 300.3 type of issue by the AHJ. So, you're on the right track, but double-check with your local electrical inspectors to make sure that they won't ding you on this!
Of course, running a 12/4 instead of the 12/3 for the switch loop lets you run a neutral with the loop -- simply connect the switch loop's neutral to the smart switch, and then do not connect the incoming-power neutral to the switch loop's neutral in the loop-end box, or else you'll definitely be violating 300.3(B)/310.10(H) due to the inadvertently looped/paralleled neutral!
And while you're at it with the walls open -- run a 12/4 for the other switch loop -- the NEC has a requirement for the neutral to be present now, even if you aren't putting in a "smart switch" straight away. (Just wirenut it off at the unused end if you want to keep the dumb switch there)
Best Answer
No. That is a Double-Pole, Single-throw (DPST) which switch both hots on a 240 volt load.
For 3-way, you need Single-Pole, Double-Throw (SPDT) switches for 120 volts or Double-Pole, Double-Throw (DPDT) switches for 240 volts.
I have no idea how easily you can find motor-rated DPDT switches. One other solution is to use DP, normally open relay, motor rated, with a 120 volt coil. And power it through standard 3-way switches.