220v question

[Bob Cooper]

I just bought a used Woodmaster 7.5HP drum sander. Motor nameplate says 32 Amps. It has a 10-50p three prong plug on it. I'm planning on running 6-3 NM wire to a 10-50r and using a 50 Amp breaker.

Here's my question. Am I doing the right thing to use the two hots and 1 neutral and just cap the ground?

[Todd Burch]

Sounds like how I would do it.

[Rollie Meyers]

Sounds like how I would do it.

And you both would be wrong. Use the grounding conductor, most 240V equipment does not require a neutral, unless it is a 208-230V single phase Hoshizaki ice machine. The only place where one was allowed to ground to the neutral was clothes dryers & cooking equipment & that is only allowed in existing installations now.

[Todd Burch]

I knew that. What was I thinking? Ground is ground.

[Wade Lippman]

Use 6-2. If you happen to have 6-3 you could use it and just ignore the neutral (not the ground, you need that), but unless something else is going on 6-3 would be a waste. Besides, 6-3 is really terrible to run; I haven't used 6-2, but it would have to be easier.

[John Lanciani]

Use 6-2. If you happen to have 6-3 you could use it and just ignore the neutral (not the ground, you need that), but unless something else is going on 6-3 would be a waste. Besides, 6-3 is really terrible to run; I haven't used 6-2, but it would have to be easier.

I'd run 6-3. Pennies more and it allows the option of replacing the outlet with a sub panel later on if needed.

[Julie Moriarty]

And you both would be wrong. Use the grounding conductor, most 240V equipment does not require a neutral, unless it is a 208-230V single phase Hoshizaki ice machine. The only place where one was allowed to ground to the neutral was clothes dryers & cooking equipment & that is only allowed in existing installations now.

+1, Rollie

I might also add that when someone else comes in at a later date to do some work and decides to tap the "neutral" in that box...
I've seen all kinds of crazy things. Nothing surprises me anymore.

Now where can I get that ice machine?

[Mark Engel]

+1, Rollie

I might also add that when someone else comes in at a later date to do some work and decides to tap the "neutral" in that box...
I've seen all kinds of crazy things. Nothing surprises me anymore.

Now where can I get that ice machine?

http://www.hoshizakiamerica.com/index.asp

[Art Mann]

+1, Rollie

I might also add that when someone else comes in at a later date to do some work and decides to tap the "neutral" in that box...
I've seen all kinds of crazy things. Nothing surprises me anymore.

Now where can I get that ice machine?

That is why one should strive to adhere to NEC requirements whether changes are electrically safe or not in a particular situation with a particular homeowner. I have been involved with a group repairing houses damaged by a disastrous group of tornados that swept through my community. It is unbelievable how some people modified their house wiring. It is a wonder their houses didn't burn down before the storm. I'm sure some of these modifications started out as something that would not satisfy code but was perfectly safe in a very specific situation.

[Bob Cooper]

Thanks all for the help. What led me to question using the ground was that the plug said 'non grounding' and the fact that the ground screw/lug wasn't a green color.

Also I used 6-3 because I had a bunch so I just capped the neutral on both ends. Getting that big 50amp plug in a 4x4 box with wire that big was a pain.

[Rick Christopherson]

Thanks all for the help. What led me to question using the ground was that the plug said 'non grounding' and the fact that the ground screw/lug wasn't a green color.

Also I used 6-3 because I had a bunch so I just capped the neutral on both ends. Getting that big 50amp plug in a 4x4 box with wire that big was a pain.

You are correct for questioning this. A NEMA 10-50 is a non-grounding 3-pole receptacle. I'm surprised that the sander came with that.
10_50r.gif

Because you ran 6-3, then you should pick the lesser of two evils, even though neither is actually code compliant. If the supply circuit is coming from a main breaker panel (not subpanel) then I would recommend connecting the insulated neutral to the terminal lug labeled "W" in the image above. It will serve as a ground as you are using this today, but in the future, someone else might use the receptacle as a proper 3-pole, and the white wire is permitted to carry current.

On the other hand, if the supply circuit is originating from a subpanel, then you should connect the bare ground wire to the "W" terminal.

[Art Mann]

Sorry Rick, but that is bad advice. The third wire is for ground - not neutral. The machine operates on 240VAC and doesn't require a neutral because no current will flow in it. I installed the wiring for a 5 horsepower version of the Woodmaster sander for a friend of mine and it didn't require a neutral. The third wire is for a safety ground. See Julie and Rollie's comments above. That is the way all 3 wire 240VAC wiring is run. If neutral is needed for some reason, to run a 120Vac variable speed conveyor for example, then it needs to be a 4 wire connection. Whether the feed line originated in the main breaker box or a sub-panel isn't relevant.

[Rick Christopherson]

Art, did you not notice the NEMA 10-50 plug and receptacle he has been talking about? No matter what advice you give him, it will be wrong. So you pick the lesser of the two. If the tool had a NEMA 6-50 it wouldn't be an issue.

The distinction between whether it is a main panel or subpanel is due to the ground to neutral bond.

[David L Morse]

.... I installed the wiring for a 5 horsepower version of the Woodmaster sander for a friend of mine and it didn't require a neutral. The third wire is for a safety ground.

You could follow code and use a 6-50. The 10-50 is the wrong connector for this application.

[Art Mann]

My objection is that he was initially proposing to attach a current carrying conductor (neutral) to the chassis of the sander. That is never acceptable, regardless of whether the panel is a sub panel. The reason is that an open fault in the neutral-ground connection could apply 120V directly to the chassis, and everything else plugged in, through some other appliance or piece of equipment. That kind of fault is not at all uncommon, particularly in old houses or newer ones with poor wiring. I have seen it happen. A 10-50 plug/receptacle might not be appropriate for his application but is specified to have 2 120V legs plus a ground. He would not be creating a dangerous situation using it this way. I'm not quite sure what the location of the single point ground (bond between neutral and ground) has to do with it.

leviton-5050-wiring-diagram.jpg
There are millions of stoves wired this way throughout the country.