Power requirement for SawStop 5hp

[Calvin Crutchfield]

I will be installing a Sawstop 5hp TS on Tuesday. (subtle GLOAT!!)

It is replacing a general 650 3hp.

Will I need to upgrade my power? I have a 20amp dedicatd ckt for the table saw using 12/4 wire with a 20amp 250v plug.

SS's website states: 5 hp, 1 phase, 230 V, 20.5 A

So I presume I am fine with what I have....But wanted to check in with the experts...

Thanks!

[Jim Becker]

IN GENERAL, a 5hp saw requires a 30 amp circuit. But you need to know the actual amperage specifications for your new saw...which you have. Since the saw requires 20.5 amps, you'll want to change over your existing circuit to support 30 amps. (minimum would be 26 amps, but the next step up is 30 amps) Unless your wire is already #10, you'll need to re-run it as well as change the breaker and receptical to support 30 amps.

[Calvin Crutchfield]

Thanks Jim. Exactly the info I was looking for.

That would be 10/4 right?

[Jim Becker]

10/2 plus ground is what you need for the Romex in the wall unless your locality requires you to have the fourth conductor. (It doesn't get used at the saw end...) For the cord if the saw requires you to install your own, the rubber stuff is often labeled 10/3...at least at my 'borg it is.

[Ted Miller]

Cal, Grounds are not numbered, so as Jim said, 10/2 will have three #10s, 2 hot and one ground. Both plug and recep will have to be 30 amp, 20 amp plugs and receps of course are smaller, so don't forget to change both ends of your SO cord...

[Eric Wong]

Jim is on the money, as always. A 30 amp circuit should do the trick. Keep in mind that a 5HP motor can draw up to 100 amps for a second or two during startup. My ClearVue cyclone is 5HP, and I've measured the current draw as high as 80 amps for the first second of startup.

The rating of 20.5 amps is "Full Load Amps", so other than at startup, it should only be drawing close to that amount under full load, ie, cutting really thick stock or in a really heavy dado operation.

[Calvin Crutchfield]

Now I'm a little confused. The current saw is wired with 12/3 (3 wires plus a ground). All four wires are used from the panel all the way to the TS switch.

is there a diagram somwhere I can see or if I just rewire the same way rdeplacing the 12/3 with 10/3 I should be OK? I have already purchased the 10/3 romex and cord. That is 3 wires plus a ground.

Thanks

[Jim Dunn]

Could I suggest running conduit and stranded wire instead of romex, please. 10ga wire is like handling a cobra thats mad.:) At least with the stranded wire you have a better chance of placing where you want it. It's much easier to work with.

I'd have to say that the extra wire is a redundant common/ground. It's probably hooked to the inside of the box where the plug is wired? If you look closely at the inside of your electrical panel you'll see that the common bar and ground bar are bonded.

[Tim Malyszko]

Could I suggest running conduit and stranded wire instead of romex, please. 10ga wire is like handling a cobra thats mad.:) At least with the stranded wire you have a better chance of placing where you want it. It's much easier to work with.

I'd have to say that the extra wire is a redundant common/ground. It's probably hooked to the inside of the box where the plug is wired? If you look closely at the inside of your electrical panel you'll see that the common bar and ground bar are bonded.

I second that. Last time I ran 10 ga wire for a 240v circuit, I ran 1/2 the length, which was in-doors using romex and the other half in as seperate, stranded uhmw wire sch 80 pvc conduit outdoors. I swear, It took me longer to run the romex and fight its stiffness than it did to glue up the conduit and pull the uhmw.

If you have the ability, seperate strands and conduit are the way to go. In addition, if you ever need to swap out the wire for a bigger gauge, the path from the panel to the outlet is already there, making it very easy to pull a new wire.

[Jim Becker]

Now I'm a little confused. The current saw is wired with 12/3 (3 wires plus a ground). All four wires are used from the panel all the way to the TS switch.
As I previously indicated, your local jurisdiction may require the fourth conductor on a 240v circuit...and that wouldn't be inconsistent with many appliances that require both 120v and 240v concurrently. When you do 240v circuits, they think, "appliance", not "power tool". The fourth conductor is the "Neutral"--usually a white wire--and is not required for a pure 240v application. If it is required, put it in, even though it serves no purpose for your saw's power requirements. If it is not required, the "Cobra" Mr. Dunn refers to will be slightly...and I do mean slightly...less ornery to deal with. It's pretty stiff stuff!

[Jim Dunn]

Mr. Dunn

Did my dad join without telling me:p

[Dave Hale]

And have some ring terminals for connecting inside the SS. Not a lot of room in their for getting the 'Cobra' hooked-up or taking that thick strand and wrapping it around the screw.

[Rick Christopherson]

As I previously indicated, your local jurisdiction may require the fourth conductor on a 240v circuit...and that wouldn't be inconsistent with many appliances that require both 120v and 240v concurrently. When you do 240v circuits, they think, "appliance", not "power tool". The fourth conductor is the "Neutral"--usually a white wire--and is not required for a pure 240v application. If it is required, put it in, even though it serves no purpose for your saw's power requirements. If it is not required, the "Cobra" Mr. Dunn refers to will be slightly...and I do mean slightly...less ornery to deal with. It's pretty stiff stuff! Your local jurisdiction will not require the Neutral for this circuit. Just because a single inspector states this, does not make it a binding requirement in local code. It is usually stated when someone makes a phone call inquiry without providing the proper information to the inspector, and then that answer gets repeated on the Internet. Furthermore, not all inspectors carry the same level of competence or knowledge of the NEC or even of their local codes.


I'd have to say that the extra wire is a redundant common/ground. It's probably hooked to the inside of the box where the plug is wired? If you look closely at the inside of your electrical panel you'll see that the common bar and ground bar are bonded.No, it is not a redundant ground, and no, it will not be connected to chassis ground inside of a properly wired tool or junction box. Doing so is a code violation and sets up a ground loop condition with current flowing through the ground wire.

[Jim Becker]

Rick, I don't disagree that it may be just an inspector's perogotive to require the fouth conductor, but there are times when it's just not worth "fighting city hall".

[David Wambolt]

I just ran some 10/2 Romex and it didn't give me any problems. It was a bit more difficult to route than 12/2. Perhaps I just got lucky? My 10/2 runs were for my 5hp Sawstop and a future 5hp 80 Gallon compressor and totalled about 80 feet.

[Calvin Crutchfield]

ok. so a little clearer now. What I am hearing is that regardless of wether I am running from the panel to the outlet or from the outlet to the saw I only need 2 wires and a ground?

From the panel is simply the red and black at the breaker itself and the ground bus. Not having that 4th wire, makes it a lot easier!!!

What was confusing me is that I had 10/3 (3 with a ground) yet the plug I saw (30amp 250v) had only three prongs not four. But it seemed that the 30amp 125/250 volt plugs had 4 prongs.

Summary: I can use 10/2 (2 with a ground) and 30amp 250v 3 prong connector?


I'm not sure why I had the extra wire on my 3hp 20amp setup...

[Ryan Myers]

If you look closely at the inside of your electrical panel you'll see that the common bar and ground bar are bonded.
This only the case if your main disconnect is in your panel, then it is ok to bond the nuetral and ground together. If your main breaker is remote from your panel then you will have a 4-wire system. In which case the neutral and ground will not/or should not be bonded together anywhere other than one time at the main disconnect. A 4-wire system should be carried out through to the end of every branch circuit.

Typically the only two appliances in a residential setting that ever need 4-wires is a range and a dryer. You should be able to run 10-2 w/ground sheathed cable without any problem. The biggest problem is in the smaller towns that don't have dedicated electrical inspectors, you get a one guy does it all. And they usually are not familiar with the electrical code well enough to make education decisions. So it is easier to just go with what they say.

Handling that "cobra" should be no problem. If it is, you may want to hit the gym. :D My personal favorite is 500 kcmil wire with a diameter of about an inch and weighs in at about 1.5 pounds per foot. This stuff will make you break a sweat trying to get it bent into a terminal.

[David Wambolt]

ok. so a little clearer now. What I am hearing is that regardless of wether I am running from the panel to the outlet or from the outlet to the saw I only need 2 wires and a ground?

From the panel is simply the red and black at the breaker itself and the ground bus. Not having that 4th wire, makes it a lot easier!!!

What was confusing me is that I had 10/3 (3 with a ground) yet the plug I saw (30amp 250v) had only three prongs not four. But it seemed that the 30amp 125/250 volt plugs had 4 prongs.

Summary: I can use 10/2 (2 with a ground) and 30amp 250v 3 prong connector?


I'm not sure why I had the extra wire on my 3hp 20amp setup...
Yes. Two insulated wires and a bare ground for your romex (Panel to Recepticle) and three insulated wires in your SO cord (Saw to Plug, White/Black/Green,Yellow). The Romex will be 10/2 and the SO cord will be sold as 10/3. Typically a white wire will indicate a neutral, but when you are running a 220V circuit, your white wire is now a hot in a x/2 wire configuration. I make sure to mark all my 220V hots in the panel with red or yellow tape so that it indicates they are not a neutral. If you were using 10/3 Romex, then you would have Black=Hot, Red=Hot, White=Neutral, Bare=Ground. If using 10/2 Romex, Black=Hot, White=Hot, Bare=Ground.

[Jim Dunn]

This only the case if your main disconnect is in your panel, then it is ok to bond the nuetral and ground together. If your main breaker is remote from your panel then you will have a 4-wire system. In which case the neutral and ground will not/or should not be bonded together anywhere other than one time at the main disconnect. A 4-wire system should be carried out through to the end of every branch circuit.

Typically the only two appliances in a residential setting that ever need 4-wires is a range and a dryer. You should be able to run 10-2 w/ground sheathed cable without any problem. The biggest problem is in the smaller towns that don't have dedicated electrical inspectors, you get a one guy does it all. And they usually are not familiar with the electrical code well enough to make education decisions. So it is easier to just go with what they say.

I've had to hook up my companies equipment in hundreds of panels and never seen a panel that had a remote disconnect. Hence my comment about the bonded ground and common. I'm just wondering under what circumstances would you find a remote main disconnect?

Handling that "cobra" should be no problem. If it is, you may want to hit the gym. :D My personal favorite is 500 kcmil wire with a diameter of about an inch and weighs in at about 1.5 pounds per foot. This stuff will make you break a sweat trying to get it bent into a terminal.

I've had to hook up my companies equipment in hundreds of panels and never seen a panel that had a remote disconnect. Hence my comment about the bonded ground and common. I'm just wondering under what circumstances would you find a remote main disconnect?

I don't want to break a sweat at the gym let alone wiring:eek::). Seriously I've just found stranded wire easier to work with on pulls. It also adds a professional look to anotherwise amateur looking job.

[Ryan Myers]

I'm just wondering under what circumstances would you find a remote main disconnect?

Jim, I wasn't trying to indicate you were necessarily wrong. Just trying to clarify different situations one might come across.

In a residential setting anytime a panel is located more than 5-10 feet inside a building most utility companies require a outside disconnect. In commercial work it varies, in larger commercial buildings a lot of panels are sub-panels because by code you can only have six mains. So if you have a main disconnect panel (MDP), every panel beyond is a 4-wire. Industrial settings can vary greatly.

I too only use stranded wire whenever possible because it is much easier to work with. Except for the de-spooling part.

[Jim Dunn]

Thanks Ryan. Codes do differ from area to area. And do I understand about the de-spooling/backlash part.