Wiring suggestions needed for table saw

[Steve Rybicki]

I just got a Grizzly G0478 table saw with a 20/10 amp motor. I could use some suggestions on getting power to this. It's in a room that has my main service panel. I will be adding a subpanel for power tools in the future, but not for a few weeks. I'd like to use the saw now, but there is only one free slot in the service panel. Grizzly says that it can be wired to a dedicated 30 amp breaker on 110V. Anyone see a significant disadvantage to this, vs. wiring for 220v down the road?

I would run #10 wire to a receptacle which would be within 15' of the service panel. The saw is about 20' from the service panel and I don't want to run any extension cords (Grizzly advises not to). I hesitate to run anything permanent along the floor, yet I'm wondering if that is the only reasonable option with a table saw. The floor is concrete with radiant heating, so no holes can go into the floor.

Has anyone located a ceiling receptacle in a spot that doesn't get in the way? Is a short extension to a wall receptacle the best option or do people find a floor conduit workable if it has side ramps built for it?

[Rick Christopherson]

Because the saw is near your service panel, and because this is just temporary until you add a subpanel, then you do have some options.

First off, even though the saw is rated at 20 amps, it will only pull this under full load, and you won't experience this too often. Secondly, even though this will max-out a 20 amp circuit, it may or may not be enough to trip the breaker.

For now, you can go to the home center and buy some flexible tool cord; enough to reach from the panel to the saw. For stranded wire this would be 12/3 with ground (total of 3 conductors: black, white, green). Install the cord directly into the load center and connect it to the saw in whatever manner you wish (either hardwire or add cord cap).

Doh :eek:, It's too early in the morning. Instead of buying the cord and adding a cord cap, just buy a heavy duty, 10 or 12 ga extension cord and cut off the male plug.

Because this is temporary and because the cord is open-air from the panel to the saw, if you trip a 20-amp breaker too often, then you can use a 30-amp breaker. You cannot do this with permanent wiring, or wiring that is not exposed for its length.

By the way, by running this saw now on a 20-amp temporary circuit, you will find out if it can be permanently run from 20 amps, or if you need to convert this to 240 volts after you get your subpanel installed. A 2 hp motor is borderline for running on a 120 volt circuit, so when you are ready to make this permanent, then it may be a good idea to reconfigure this for 240 volts.

[Chuck Lenz]

I think you should call a electrician. It might cost you a little extra, but you'd have the peace of mind knowing that it's right.

[Kent Fitzgerald]

Grizzly says that it can be wired to a dedicated 30 amp breaker on 110V. Anyone see a significant disadvantage to this, vs. wiring for 220v down the road?

The saw should be fine on a dedicated 120V, 30A circuit, as recommended by Grizzly. Switching over to 240V requires a new magnetic switch (about $60), and you're close enough to the panel that you wouldn't see any benefit.

As far as getting power to the saw, bear in mind that you will want to run dust collection as well, so you might as well plan for both. I'd suggest you set a post (e.g., a 2x4) from ceiling to floor on the right side of the saw, to provide a convenient place for a receptacle and a DC drop. If you can't drill into the floor, the post can stand on a base plate glued down with construction adhesive.

[Bill Arnold]

The saw should be fine on a dedicated 120V, 30A circuit, as recommended by Grizzly. Switching over to 240V requires a new magnetic switch (about $60), and you're close enough to the panel that you wouldn't see any benefit.
...
According to page 47 of the Grizzly manual, the magnetic switch remains the same for either 110V or 220V operation.

The only benefit of 220V operation is lower voltage drop across the wiring between the distribution panel and the saw. If you're within a few feet of the panel, you'd be hard-pressed to see any difference in operation.

As I was building my new shop, I ran dedicated 220V circuits for any machine that could be operated on the higher voltage. The longest run to any machine is probably no more than 40', so this becomes a personal preference more than anything.

[Steve Rybicki]

I tried the easiest method first. I plugged it into an existing dedicated 20 amp breaker. The saw ran fine, but when I put it under load, the breaker popped.

Next, I'll put in the 30 amp breaker and I'll bring some #10 wire to within a few feet of the saw.

Thanks for the suggestions.

[Kent Fitzgerald]

According to page 47 of the Grizzly manual, the magnetic switch remains the same for either 110V or 220V operation.

Bill, you're misunderstanding the manual. Page 11 clearly states, "the Model G0478 is prewired for 110V operation. If you plan to rewire your machine for 220V, you must use a different magnetic switch."

The switch wiring connections, as shown on page 47, are the same for either voltage, but the switch itself is different.