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Discussion Starter · #1 ·
Hi, I am thinking about getting a 3HP SawStop table saw. I'm a typical serious late night/weekend woodworker. I have 2 each Legrand Pass and Seymour 250V, 50A receptacles in my garage on 2 separate circuits. It has 3 straight blades and one U shaped terminals.

I unfortunately was not around when the electrician installed these 220V receptacles, but he did assure me that he knew what a 3HP SawStop was when I told him what I would use this outlet for. I was told by another electrician that this receptacle is typically used for charging electric vehicles at home. Will this work for a 3HP SawStop? Will I have to get a different plug end for the saw when I order it or do I need a different receptacle for my wall? What is my receptacle typically used for? Thanks!
 

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where's my table saw?
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That's a 50 AMP for 3 wires and a ground lug. The ground would go to your chassis or cabinet if your saw's wiring has 4 wires?
Type 14--50R
 

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Discussion Starter · #3 ·
That's a 50 AMP for 3 wires and a ground lug. The ground would go to your chassis or cabinet if your saw's wiring has 4 wires?
Type 14--50R
After downloading the sawstop manual just now, it says the saw comes with a NEMA 6-15P (3 terminals) on the end of a 9 foot power cord. So the 6-15P is 3 wires, black, white and green. In my case I guess I could use a short adapter to go from 6-15R to 14-50P? The 4th wire in the 14-50 would not be used? So I think I do not have to change the saw or my wall receptacle. Just need a short adapter to go from 6-15R to 14-50P.
 

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Hi, I am thinking about getting a 3HP SawStop table saw. I'm a typical serious late night/weekend woodworker. I have 2 each Legrand Pass and Seymour 250V, 50A receptacles in my garage on 2 separate circuits. It has 3 straight blades and one U shaped terminals.

I unfortunately was not around when the electrician installed these 220V receptacles, but he did assure me that he knew what a 3HP SawStop was when I told him what I would use this outlet for. I was told by another electrician that this receptacle is typically used for charging electric vehicles at home. Will this work for a 3HP SawStop? Will I have to get a different plug end for the saw when I order it or do I need a different receptacle for my wall? What is my receptacle typically used for? Thanks!
I have seen this outlet used for ovens, RVs, and welders.


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You will probably void the sawstop warranty by plugging the 15 amp cord into the 50 circuit. Don't do this. It's dangerous. Yes it will work, it may also burn down the house or kill you.

If your panel is in the shop run a new circuit with 14\2 wire. 2 hots and a ground on a 15 amp double breaker.
 

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I would call the electrician that installed this for you and ask him to swap out to the proper outlet. He should know better.

The outlet he installed has three current carrying wires and one non-current carrying ground. The typical US home service has two 120 volt AC poles that are 180 degrees out of phase. You get 120V by going from either of these to ground using a current carrying neutral wire. When you go between the two poles, they add up to 240V. The outlet the electrician installed (if he did it right) delivers both 120V and 240V options to the receptacle. Two wires connect your two phases. The other two connect to your ground lug (the insulated one is rated to carry current and it is your neutral wire).

The amperage of the circuit does not matter in this case except that the wires run for a 50A circuit are much thicker than a standard 20A circuit (meaning you likely overpaid). Think of amps ratings like a speed limit and as long as you stay below it you're good.
 

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Ancient Termite
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Let's back up for a moment. The job of the circuit breaker is to protect the WIRING inside the walls. With appropriate wiring from the wall to the device 15 amp or 50 amp makes no never mind. The device will only draw as much amps as it is needed.

Look at it this way. Charging a laptop draws barely any amperes and a toaster or coffee pot would draw significantly more current or amps. You could plug a free-standing range and oven into the 50-amp circuit with the appropriate power cord. Just as with the appropriate power cord you could power your laptop.

As a point of note, the receptacle offers two 120-volt lugs, one neutral lug and one ground lug. From either lug to neutral you would measure 120 volts; between the two lugs you would measure 240 volts.

A vital point of note on used machinery. If the power cord has 5 lugs it is probably a three-phase machine. A three-phase machine will not run properly on single phase power.
 

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there isn't really an easy homeowner fix here. you have a 240/120 VAC 50a supply, and a 240VAC 15a load.

  • swapping out the receptacle for a 6-15R would mean trying to insert #6 or #8 wires in to a 15 amp receptacle, won't work.
  • replacing the plug on the saw's power cord with a 14-50P not advisable (not sure what code says there)

best to call the electrician back out to give you what you need. frankly i question the 6-15R for a 3 HP motor...
 

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Seems to me that it would be fine to run with an adapter plugged in. If the saw motor stalls out the thermal switch in the saw should pop before even a smaller circuit breaker would anyways.
 

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Let's back up for a moment. The job of the circuit breaker is to protect the WIRING inside the walls. With appropriate wiring from the wall to the device 15 amp or 50 amp makes no never mind. The device will only draw as much amps as it is needed.

Look at it this way. Charging a laptop draws barely any amperes and a toaster or coffee pot would draw significantly more current or amps. You could plug a free-standing range and oven into the 50-amp circuit with the appropriate power cord. Just as with the appropriate power cord you could power your laptop.

As a point of note, the receptacle offers two 120-volt lugs, one neutral lug and one ground lug. From either lug to neutral you would measure 120 volts; between the two lugs you would measure 240 volts.

A vital point of note on used machinery. If the power cord has 5 lugs it is probably a three-phase machine. A three-phase machine will not run properly on single phase power.
This is why electrical issues seem easy, but at the same time can be deadly.

The sawstop electrical system is designed around the 15 amp cord, motor and switch. Most likely the breaker can be a 20 amp, read your manual. Plugging into a 50 amp circuit means that the breaker will most likely never trip. Someone will most likely die before the breaker trips. You I can care less about, the innocent person walking in I care about.

The laptop, coffee maker or toaster are all designed around the 20 amp appliance circuit in the kitchen. They all have a 15 amp plug on them
 

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Discussion Starter · #12 ·
Here's an update. I confirmed that the saws I want (sawstop 3HP and Laguna 2.5 HP bandsaw) will draw 13 and 9.8 amps respectively. Both saws will have cords with NEMA 6-15P on the end. I discussed this with my electrician and he now recommends a 20A breaker. He says the issue now is that the 14-50R I already have was wired with 6 gage wire. The 6-15P takes 12 gage or 10 gage. So the existing 6 gage wire may be too fat to fit into a 6-15R. It turns out, I had him also give me two 20A 120V outlets with wire thick enough for 30A. This is in addition to the two 50A outlets with the 6 gage wire. So I'll see if he can convert at least one of those 120V outlets to 220 V. I work alone so I would never operate the 2 saws at the same time, so I could have two 6-15R on the same circuit I guess.

I will operate a shop vac with a dust separator on it at the same time as the saws, but I have other 120V 15 A outlets for that.

Does this make sense as far as safety is concerned?
 

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I would have no problem running a 3hp saw stop on a 30A or a 100A circuit. Just swap a 14-50p to the the sawstop cord. The 14-50 or 6-50 is only NEC rated for a 3hp single phase motor. NEC also requires a 30A minimum circuit for a 3hp motor regardless of the actual FLA listed on the plate.

The mag starter provides the overload protection for the motor. The braker protects the wiring. The correct sized 30a minium circuit would already be enough to allow the motor to damage itself without the starter overloads since it's only 13.4FLA. Moving to 50A makes no difference.
 

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Discussion Starter · #14 ·
I would have no problem running a 3hp saw stop on a 30A or a 100A circuit. Just swap a 14-50p to the the sawstop cord. The 14-50 or 6-50 is only NEC rated for a 3hp single phase motor. NEC also requires a 30A minimum circuit for a 3hp motor regardless of the actual FLA listed on the plate.

The mag starter provides the overload protection for the motor. The braker protects the wiring. The correct sized 30a minium circuit would already be enough to allow the motor to damage itself without the starter overloads since it's only 13.4FLA. Moving to 50A makes no difference.
Ok thanks. So my 14-50R has 4 conductors. The sawstop and bandsaw would have only three. So you are saying the rewired 14-50P cord in your example simply would not use the 4th wire? I was concerned that somehow the saw would command current at a level beyond its 13 amp rating (I have no idea how it would do this! Cutting thick hard wood??) so in my mind, the saw could potentially melt itself or my garage unless the house breaker was closer to its 13 amp rating than 50 amps, say 20 or 30 A. Maybe I need to contact sawstop to run my situation past them?

I am trying to figure out if I can use the house breaker as a line of defense in case of something going wrong. Hope that makes sense, it's debatable if it does for me, lol.
 

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I was concerned that somehow the saw would command current at a level beyond its 13 amp rating (I have no idea how it would do this! Cutting thick hard wood??)
Disclaimer: I'm one of the less experienced forum members. I'll say what I think of it, someone else can correct me if needed.

It's my understanding that rating, 13 amp in this case, is what the motor will draw at maximum load, at lesser loads it draws less. The only time it goes above that rating is at start up, it can/will spike above it for a fraction of a second. Too brief and still not enough to damage wiring etc, but the breakers etc need to be able to handle the brief spike.
 

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Discussion Starter · #16 ·
Disclaimer: I'm one of the less experienced forum members. I'll say what I think of it, someone else can correct me if needed.

It's my understanding that rating, 13 amp in this case, is what the motor will draw at maximum load, at lesser loads it draws less. The only time it goes above that rating is at start up, it can/will spike above it for a fraction of a second. Too brief and still not enough to damage wiring etc, but the breakers etc need to be able to handle the brief spike.
That makes sense, thanks.
 

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Inrush (starting current) can be 10x the FLA. That is only for a split second though.
Ok thanks. So my 14-50R has 4 conductors. The sawstop and bandsaw would have only three. So you are saying the rewired 14-50P cord in your example simply would not use the 4th wire? I was concerned that somehow the saw would command current at a level beyond its 13 amp rating (I have no idea how it would do this! Cutting thick hard wood??) so in my mind, the saw could potentially melt itself or my garage unless the house breaker was closer to its 13 amp rating than 50 amps, say 20 or 30 A. Maybe I need to contact sawstop to run my situation past them?

I am trying to figure out if I can use the house breaker as a line of defense in case of something going wrong. Hope that makes sense, it's debatable if it does for me, lol.
There are overloads inside the magnetic starter that protect the motor. That is their purpose.

The breaker only protects the wiring.

The national electric code specifies you use a 30A circuit for a 3hp motor.
 

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Discussion Starter · #18 ·
Inrush (starting current) can be 10x the FLA. That is only for a split second though.


There are overloads inside the magnetic starter that protect the motor. That is their purpose.

The braker only protects the wiring.

The national electric code specifies you use a 30A circuit for a 3hp motor.
Ok thanks. I was missing your point about self protection of the saw motor. So the 2 outlets I currently have wired for 110V and 20A could be converted to 220V and 30A breaker. The electrician told me he used wire gage to support up to 220 V, 30 A in those. My instinct is saying not to use those 14-50R for anything other than charging an electric car, which I have no plans to buy.
 

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I recommend 10ga wire on a 30a circuit at a minimum.

If you already have 6 or 8 ga wire run, I believe you can splice in 10ga wire and replace the breaker. Verify with someone more familiar with NEC. Aka, call back your electrician...but bring this knowledge with you to validate his approach...because it sounds like he messed up before...

I might actually recommend a different electrician...
 
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