Table saw Disconnect?

Brent Dowell

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Do any of you use a disconnect in addition to your main on/off switch?

I finally got around to running a 220 socket that I can use for my table saw. I put it on the ceiling with a locking plug. It comes down from the attic area same place where my dust collection goes up, so it's nice and out of the way.

I was just wondering if it would be recommended to have an additional disconnect since I will no longer be able easily unplug the saw.

If so, do you have any recommendations on what kind of disconnect to get?
 
I don't, but the connection from the saw is via a whip (heavy extension cord) with just a short plug cable on the saw so I can still unplug right there when desired.

I like a physical disconnect when we're out of town or it looks like a thunder storm is approaching...
 
For the 220v lines in my shop, I'm doing the same, just a twist lock plug on the cord. My TS has a plug going to the motor from the switch to remove it for maintenance, which gets unplugged when changing blades.
 
When I wired my shop, I ran individual 220V circuits to each tool that needed it, plus a couple of extra circuits in case I need them sometime. Each is on its own circuit breaker in the distribution panel so I can kill it when desired.
 
Its probably worth knowing that ~most~ circuit breakers have a relatively low duty cycle in use as a disconnect. Frequently flipping them on and off "wears them out" (to vastly simplify) whereas purpose made disconnects have a much higher cycle rating. The failure mode is pretty benign though in that you just end up getting more nuisance trips as the locking do-dad inside the circuit breaker starts to fail.

Having said that the same is true for most outlets and frequent plugging/unplugging will eventually fatigue the contacts leading to poor contacts (which is why outlets in the kitchen tend to fail faster than outlets elsewhere in the house).

I went in knowing this, and only unplugging most of my machines ~weekly~ to ~monthly~ (on average) I figured I had 5-10 years of service on a L6-30P outlet on the end of a whip so it was still cheaper than adding a proper disconnect and I can just replace it eventually (and I'm unlikely to be in this house that long).

If I was building out a shop for real real I'd put in a sub panel with a physical disconnect before all of the machines that I'd want of at the end of the day (lights on a separate circuit). Having "real" per-machine disconnects would be "better" but there's a cost/benefit trade off as well.

Also having the machine be "plug in" I can claim that its not a dedicated circuit which changes the NEC rules I'm operating under ;)
 
... If I was building out a shop for real real I'd put in a sub panel with a physical disconnect before all of the machines that I'd want of at the end of the day (lights on a separate circuit). ...

Ditto on this! The one thing I regret about setting up the distribution panel in my shop is not installing two of them. It would be too much of a hassle now but, if I were to do it again, I'd have one panel for lights, some 110V circuits, and one 220V for A/C; then a second panel with a main disconnect for all of the big tools, air compressor, etc.
 
i have a disconnect right below the saw height adjustment wheel that i hit ever time i change blade or am out of town.. trip it with my foot and on with foot, dont trust no switch on saw.
 
i have a disconnect right below the saw height adjustment wheel that i hit ever time i change blade or am out of town.. trip it with my foot and on with foot, dont trust no switch on saw.

What kind of disconnect?

I did get a sub panel installed recently. This weekend I used the existing switched circuit from the main panel to run all the lights in the shop and ran a dedicated 220 for the Air Compressor and another dedicated 220 for the Table saw.

I had already run another dedicated outlet from the sub panel for the Dust collector.

I ran another 110 circuit to use for other tools. I'll probably run another 110 circuit at some point as well. Really makes it a lot nicer as I'm not overloading any thing at this point.

I might think about putting a disconnect on the entire panel. It doesn't have one right now, but I'd like for the table saw to have something right next to it to make it easier and more likely that I would use it when changing blades.

I've already got the plugs I would need to do the disconnect at the saw, so will probably do that for now.
 
How big is the circuit to the saw?

For things in the 20-30a range you can just buy a switch and wire it inline. Above that you start needed more expensive disconnect setups.
http://www.homedepot.com/p/Leviton-...ble-Pole-Switch-White-R62-03032-2WS/100356941

Some of the hubble stuff is a bit heavier duty
https://www.amazon.com/BRYANT-ELECTRICAL-PRODUCTS-HUW-HBL7832DS/dp/B007IK9NEO

Their catalog is perhaps worth perusing for ideas.
http://www.hubbell-wiring.com/press/catalog/F.pdf

Note that these aren't isolating disconnects, so something like lightening can still bridge the contacts if you're real unlucky but its better than a swift kick in the shin and you're much less likely to have a problem.

For higher amp stuff and the main panel I'd be looking more at the hubble catalog (or their competitors) for an isolating switch. Be aware that most of the "knife" switch type switches are mostly intended as "no-load" switches and if you switch them under load you can risk arcing and possibly welding the contacts together (which can have .. unfortunate.. effects on downstream equipment - arcing == noise) so I would tend to avoid those for emergency shutoffs and probably pay a bit more for a disconnect that is capable of working under load with no risk of failure for the main shop panel.
 
I have the 220 volt circuits on 10# wire with 30amp breakers. Table saw claims 18amps, Air compressor claims 22.5 amps.

Guess I thought I'd need something fancier than a simple double pole switch. That could certainly work.
 
I did what Ryan suggested in his first post, keeping the plug in the front of the saw so I could reach it easily. I have seen pics of disconnects put on the saws and considered that, just never got around to doing it.
 
this what i have brent,, i just split the power cord from switch to box to power supply recpt. i can unplug from power supply and move the saw with the disconnect still attached.. BOX


 
I only have One 220 Volt line into my Garage/Shop which powers my Air Compressor and my Table Saw. I used to plug and unplug depending one was needed but awhile back I installed two outlets with a switch in between in a 3 gang box. Switch up is Compressor Switch down is Table Saw, in the middle is off.

220.Switch.jpg
 
The 240 volt outlet for my Unisaw is 50" off the floor on the wall near my Unisaw. I've attached a heavy string between the plug and the outlet to keep the plug and wire from falling when it's unplugged. I unplug the saw whenever I'm changing blades or working inside the saw.

Since the start button is so easy to hit accidentally, I've also added a toggle switch to the side of the box housing the start and stop buttons, to open the start button circuit. I keep this switch in the OFF position whenever I'm not using my saw, so if something should hit the start button, the saw won't start unexpectedly.

Charley
 
I only have One 220 Volt line into my Garage/Shop which powers my Air Compressor and my Table Saw. I used to plug and unplug depending one was needed but awhile back I installed two outlets with a switch in between in a 3 gang box. Switch up is Compressor Switch down is Table Saw, in the middle is off.

View attachment 97385

That's pretty clever Dan!

The 240 volt outlet for my Unisaw is 50" off the floor on the wall near my Unisaw. I've attached a heavy string between the plug and the outlet to keep the plug and wire from falling when it's unplugged. I unplug the saw whenever I'm changing blades or working inside the saw.

Since the start button is so easy to hit accidentally, I've also added a toggle switch to the side of the box housing the start and stop buttons, to open the start button circuit. I keep this switch in the OFF position whenever I'm not using my saw, so if something should hit the start button, the saw won't start unexpectedly.

Charley

Interesting....
 
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