I am looking for a book or internet instructions detailing how to install a 220V breaker and wiring to an existing breaker box. I have space to add an additional breaker but I’ve never done this before. I will be re-wiring my contractor’s table saw for 220V and connecting a new 18″ bandsaw to the circuit as well (not to be run simultaneously). I’ve read that 12 gauge wire and a 20amp circuit is recommended but I want to find step-by-step instructions on how to do the installation and connections. Any good books or internet sites out there to help me?
– Lyptus
Replies
I called this up from the breaktime over at homebuilding
200
I am not an electrician but did add my own for a 220V bandsaw. I used 10/3 with a ground. 20 amp C/B. There are some info that is missing from your post they may ask about. Try and post your question over at breaktime under the general tab as you did here.
Semper Fi
If he posts this at BT, more likely than not, most are going to say, "if you have to ask, hire an electrician."********************************************************
"It is what we learn after we think we know it all, that counts."
John Wooden 1910-
Go to Home Depot or Lowes. They sell "how to" books for electrical. Almost any book will tell you what you need.
I've used Taunton's "How to Wire a House" (or something like that) with good success. Also "Wiring Simplified"--the green book they sell at Home Despot and the like. Adding a 220 circuit is an easy matter. I used 10/2 (2 conductors plus ground), which is overkill for stationary power tools--12/2 will do just fine. I used the bigger wire because you never know when you might want to run bigger equipment and it's easier to replace the breaker and receptacle than to run new wire in the future. You said that you have an open space in your panel, but of course you need 2 open speaces for a 220 breaker. You probably knew that--just making sure. http://www.gardenweb.com has a great wiring forum.
Cheers,
Warren
Because this is a dual voltage motor, it means that it will draw less than 10 amps at 240 volts, so if you wanted, you could use a 15 amp circuit with #14 wire. You are correct that using a 20 amp circuit with #12 wire would be more prudent for the future. There are a lot of people that will tell you to install #10 wire for future use, but not very many of them tell you that they actually used it later on. That’s because most home/garage workshops don’t have 5 horsepower tools.
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Before I answer your question in the text below, I also want to draw your attention to the fact that if you are running a new circuit to your existing saw, that there is no reason for you to change the saw to 240 volt operation. The people that tell you that you should change your saw from 120 volts to 240 volts, do not understand motors or wiring. Since this statement will likely draw comments from this forum, I will wait until then to redress those comments. In the mean time, here is your answer.
==========================
Running the circuit is no different than running a 120 volt circuit. As long as you are not in Chicago, you can probably use romex, so pick up the necessary length of 12-2 wire. This wire will have three conductors inside the sheathing; two insulated current-carry conductors, and an uninsulated ground wire. You will also need a 2-pole breaker; 20-amp for #12 wire, or 15-amp for #14 wire. Before going to the store, check the brand and model of your load center to make sure you get the correct breaker--they are brand-specific.
At the junction box for the tool, strip away at least 8-inches of the outer sheathing from the romex, but be careful not to nick the inner insulation for the individual wires. When the wires are installed in the junction box, at least 6-inches of the unsheathed cable needs to extend beyond the front face of the box (that is code). The Romex also needs to be clamped at the box, or wire-stapled within 6 inches of the box.
You have two choices for you receptacle: The Nema 6-20R is the straight blade type that fits both 15 and 20 amp plugs, or the L6-20R is the twist-lok version. I prefer twist-lok, but it is entirely up to you.
Because this is a 240 volt receptacle, it makes no difference which of the white/black wires goes to the lugs. The bare ground wire must go to the green-colored lug. I am not sure if this is actually a code requirement, but it certainly doesn’t hurt to wrap a little piece of black tape around the white wire to indicate that it is a “hot” wire.
New Edit:Because of another question later in this thread, I have confirmed that code does specifically require you to re-identify the wire in some way.
An important note is that you need to be careful not to nick or score the copper when you strip off the insulation. Even a tiny surface score from a wire stripper is enough to weaken the copper and the wire will break with just a little bit of bending. If you nick the copper, cut it off and restrip the insulation.
So far up to this point, you are not working with any dangerous potential because the wires are not yet inside your load center. If you wish, you could hire an electrician to make the final connection at your load center, and the cost will be low. Assuming you proceed on your own, here is the remainder of the procedure:
=============================
OK, here comes the tricky part:
Depending on your comfort level, shut down the main breaker at any point in this part of the procedure. Since this typically means working in the dark, I normally leave the main breaker on because there are very few exposed parts in the load center that are energized. The greatest dangers are when you are working with the bare ground wire, or when you are inserting the breaker into its slot. Any sane person will shut down the main breaker before they remove the cover from the load center, but I do not claim to be sane.
At your load center, the romex must pass through a wire clamp and be secured. You need to strip away all of the outer sheathing from the cable that is inside the load center (do this before putting the wire through the clamp). Again, be careful not to nick the inner insulation on the individual wires. This is the worst place to skimp on wire. Don’t be afraid to have 3-feet of wire sticking out of the box. You can cut it to length after you have routed it.
Neatly route the ground wire to the ground buss bar. Don’t make the mistake of trying to cut the wire to exact length. Loop the wire above or below the buss bar in a “U” shape (note how your previous wires are routed). Find an open lug to insert the ground wire into. You cannot have more than one wire in the same lug.
By the way, when I am doing this, I literally put one hand behind my back and work single-handed. As long as you have only one hand inside the box, you can’t get zapped, even if you touched a hot wire. I do this even when I think the panel is not energized. For safety, I treat all wiring applications as though the circuit is active, regardless whether it is or not.
Neatly route the white and black wires along the side of the load center to the future-location of the new breaker. Again, don’t try to cut them to exact length, make them a little longer than needed and put a U-loop below the breaker’s position. Make it as long as you want as long as it is neat, but never make it short!
Strip away no more than 1/2-inch of insulation from both wires. With the circuit breaker uninstalled, and in your hand, insert the two wires into the breaker and tighten the lugs.
If you are not sure how to insert your breakers into the load center, then this is definitely the time to shut off the main breaker, because you will be energizing the wires. Most breakers have a hook on the wire side of the breaker, and this needs to be inserted first. Once hooked, then press the breaker down onto the bus bar.
With the new breaker still off, turn on the main breaker, then turn on the new breaker. If the new breaker trips, you probably made a mistake back at the outlet. If the main breaker trips, then you need to shut everything down and call an electrician to check your work.
If you want to learn more about electricity and wiring, take a look at “Electricity in the Woodshop” on my web site. It is one of the most commonly referenced articles on the internet.
http://waterfront-woods.home.att.net/Articles/Electricity/electricity.htm
Edited 11/14/2006 7:38 pm ET by RickChristopherson
Rick,
Those are great detailed installation instructions. And your web site is an excellent source of information.
Yes, you are going to get a lot of response to your 120 vs 240 motor voltage supply advice. I agree with your advice, but I'll let you handle the responses.
One comment about your 240 wiring scheme. Why don't you advise 3 conductors plus ground? (two hot, one common, one ground)
Rich
The reason why you don't use #12/3 cable is because the tablesaw does not use the Neutral (aka: common). Neutral and Ground are not the same, and they cannot be treated as the same. To do so is a code violation and a safety risk. Even if someone convinced you to run the Neutral to the saw, there is nowhere to connect it, so what would you do with the extra wire? The whole 120 versus 240 myth is the reason why I even started writing "Electricity in the Woodshop", but as I progressed into the discussion I realized I needed to provide a lot of background information first. One thing lead to another and I decided to make it a full blown electrical primer.The only time switching a motor to 240 is beneficial is when the original circuit is not sufficient for the load. That is the reason why it is pointless to switch a motor to 240 when someone is running a new circuit. As long as a person is going to run a new circuit, they may as well make it 120-volt, 20-amp and the motor will be just as happy, without going through the hassle of converting the motor.The motor doesn’t know the difference. It’s internal windings are seeing 120 volts regardless how it is configured. It will not run cooler, will not have more power, will not be cheaper to operate.
Edited 11/7/2006 1:03 pm ET by RickChristopherson
It'a all in a name. Something designated as neutral sounds safe. So many don't realize the neutral line is as hot as the hot line. I still don't think you should mess around with 220 lines, if you have to ask. You mess up with 110, you get a shock, you mess up with 220, you don't generally get to ask what happened.
Daryl,
"So many don't realize the neutral line is as hot as the hot line."
Huh? The neutral (common) line is (or should be) at ground potential. The neutral and ground lines cannot be used interchangeably, but neither is ever a "hot" line. They both come off the Common bar in the supply panel (to which the Neutral line from the incoming 240 is also attached.) The ground line is then also "grounded" to a suitable Earth ground and then run through the building.
So how can you call the Neutral line hot?
Rich
Rich,
Daryl’s intentions are correct. It is only his use of the word “Hot” that is confusing. Insomuch as Neutral is just a name we assign to the wire, so is Hot, and therefore it is incorrect to say they are the same.However, Daryl’s intention was to point out that both the Hot and the Neutral are current carrying conductors, and the only difference between the two is that one of them is anchored to a local ground potential. If one of the two wires was not anchored to a known voltage, then they both would “Float” to some unknown voltage, which in all likelihood would be in the thousands of volts range due to the high voltage of our electrical transmission system. The only reason this doesn’t happen is because each of the step-down transformers in the electrical grid is also grounded as a reference point.Technically, if you disconnected the ground back at your transformer and inside your house, you could re-ground your home electrical system using one of the otherwise Hot wires. This wire would then become the Neutral, but it would not be called the Common. In this case, the Common wire would be at 120 volts to ground instead of equal to ground.
"both the Hot and the Neutral are current carrying conductors, and the only difference between the two is that one of them is anchored to a local ground potential"
Right. And the consequence of coming in contact with the "hot" wire is that current will flow through your body to ground (of it can), while coming in contact with the neutral wire is that there is no current flow through your body because there is no potential difference between neutral and ground. Yes, the neutral wire carries current, to ground. But identifying it as a "current-carrying wire" seems to imply some dangerous potential for that wire that it doesn't have.
The whole rest of your reply describes a combination of situations that, while technically intriguing, is so unlikely as to be impossible (or improbable until the end of the universe as we know it.)
BTW, my 240 volt saw installation requires 3 conductors plus a ground.
Rich
Edited 11/7/2006 5:18 pm ET by Rich14
**Yes, the neutral wire carries current, to ground. But identifying it as a "current-carrying wire" seems to imply some dangerous potential for that wire that it doesn't have.**It doesn't imply anything. It is what the wire is! Furthermore, it does not carry current to ground. It is the return back to the source. It is thinking like this that makes people believe that the Ground and Neutral are the same. They are not. Is there a point to why you are arguing this; what is it that you are trying to get at? If I knew where you were heading with this, it would be a lot easier to explain it to you.The Ground wire is not a current carrying conductor, but if you set it up as one, you not only violate the NEC, but you defeat the purpose of the ground.What tablesaw do you have that requires a 3-wire, plus ground installation? It's either not a standard domestic tablesaw, or is has been modified from the factory configuration. I suspect the latter.As for the information in my posting, it is not unlikely at all. Floating grounds is a very common problem and a lot of people have been electrocuted because of it. It is the reason why the NEC is so stringent with grounding conditions.
Edited 11/7/2006 5:55 pm ET by RickChristopherson
Rick,
I'm not arguing at all. The explanations given have been a little confusing. Floating grounds are common, but the complex picture you proposed with gross wiring errors back through the utility transformer are not. You seem to have a problem with someone questioning you. Questions don't constitute an argument.
My saw is a Hammer C3-31 which contains three 4 hp motors and electronic control circuitry, motor braking, switching circuits for reversing the shaper motor and other functions.
No this is hardly a common shop machine. and most saws would not require 3 conductors plus ground. But if one is stringing 240 in a new installation, I think it would be a good idea to pull 3 conductors and ground at the time of the new install. It's just as easy, it costs little more, and it gives the opportunity to use the additional capability, should that become necessary.
Rich
I don’t have a problem with someone questioning me. It doesn’t happen very often, but I don’t have a problem with it. I don’t mind someone arguing either, but arguing for the sake of arguing is a different matter. Don’t take that the wrong way because I really got a chuckle out of your last posting.You made a statement that your “tablesaw” uses the neutral, so therefore it is appropriate for other people to install 240 volt circuits to include the Neutral. It wasn’t until I questioned this statement that you reveal that it isn’t a tablesaw at all: it is a European combination machine three motors and an electronic controller.Not only is this an exception to the norm, it is an unusual exception at that. Moreover, you aren’t running this saw off your routine 20 amp circuit either. At a minimum just one motor requires a 30-amp circuit, but if all three motors are permitted to operate at the same time, it needs a 50-amp circuit. And you want to compare your system with a person hooking up a dual voltage motor? That’s arguing for the sake of arguing.Yes, I am still grinning. It’s kind of funny to me that you tried to pull this over on me. DEFENDANT: But your honor, I couldn’t possibly have been speeding because my car is stuck in second gear.
JUDGE: What kind of car do you drive?
DEFENDANT: Just a McLaren F1
Rick,You're pretty much off in left field with most of this.You tried to use an absurd example of power company and house wiring mistakes to prove a point about proper wiring. A real-world example would have done.I suggest wiring a new 240 installation with 3 conductors and a ground only because it's really the smarter way to go. Why wire for a limited application to start out with? Arguing for the sake of arguing? That seems to be your bag.I wasn't trying to sand bag you at all regarding my machine. Why you are that suspicious, well only you can answer that. It was an honest answer to your question. The combo machine has on-board electronics requiring 120, hence the neutral wire. Many single-purpose newer machines have electronics requiring (or will require) more than 2 wire 240 power just for motor windings.Only one motor on the combo machine can run at any one time. It isn't THAT much of an uber machine! So during any given operation, there is nothing that exotic about it. Just a combined need for 4 hp worth of single phase power and low voltage for control circuits.I thought you gave pretty good instructions in carrying out the wiring and thought your web site had good info.I didn't realize how condescending you were for a few more messages, but looking at your first post, it's all there.Have fun.Rich
Rich14,
Now I am really confused about this whole situation. Five days ago you were arguing this point because your tablesaw required the Neutral. Since this isn’t normal, I asked you what kind of saw it was, and you responded with, “My saw is a Hammer C3-31 which contains three 4 hp motors and electronic control circuitry, motor braking, switching circuits for reversing the shaper motor and other functions.” When I “chuckled” about you trying to pull one over on me because this isn’t a standard saw, you responded by saying, “I wasn't trying to sand bag you at all regarding my machine.
Now for the real puzzler: this morning I see a posting where you are asking for advice on which combination machine you should buy; the Hammer C3-31 or the MiniMax. Unless there is a glitch in the forum software, this discussion took place this morning, 5 days after you claimed to own the Hammer machine. You stated, “I had all but finalized the order for a Hammer C3-31 combination table saw/shaper/jointer/planer.”
So you entered into this electrical argument with a well known electrical expert on the basis that your machine required the Neutral, yet you don’t even own the machine yet?
From the outset I was privately doubting the validity of the need for the Neutral on this machine, but since I couldn’t locate any specifications on the tool, I could not publicly question the statement. Now I learn that you invented the whole story.
What you took to be condescending was because you were arguing a topic that you don’t have any knowledge about, with someone that has a very great knowledge about it. It is very frustrating to have someone argue a point when their only argument is “a feeling”. It is one thing to question information, but it is an entirely different thing to argue it.
Now you know why the experts get a little short when someone legitimately asks a basic question.
Jack
JLM and RickCalm down guys. And climb off your high horses, too. I do all my homework when I purchase anything. Especially something this expensive. I have all the specs for the Hammer and I have already spent hours on the phone talking it over with the salesman and others.I don't have enough 240 wiring in my shop for the machine and I was told to bring in 3 conductors and a ground to the service outlet.No, I don't have either machine, yet. What difference does that make? What do you think one does with a purchase of this magnitude? Buy the thing on Ebay, then read the instruction manual after it arrives? Yeah, that'll work, $11,000 after the fact.I already have a 240 V box in the garage. This is a new house, but I didn't design it or spec how it should be wired. The box is yet unused. It was installed by the builder as a convenience, without anticipation of the kind of equipment that would be run from it. It's not for a clothes dryer, that installation is in the laundry room. It's not for anything in particular. Guess how the box is wired? 3 conductors and a ground. Now, don't you think that was a smart thing to do? I guess some other people think the way I do, too.That box will actually be used for a 5 HP Clear Vue cyclone dust collector. No it doesn't need but 2 conductors and ground. So that white wire in the box will go unused, for this application. But I'm sure glad that box is wired the way it is, should I ever need it. Gosh, what over-engineering! How wasteful!Now that you've read my post about the Hammer vs MiniMax machines, you can also read my followup about my trip to Phoenix to see the MiniMax. The guy demonstrating this machine also advised me to wire with 3 conductors. He was not sure about the machine needing that, but said that's the way he wired his shop. He has the large MiniMax Technomax machine which he is running single phase, although it comes 3-phase also. That machine has on-board electronics. Maybe that's why he has 3-conductor wiring. I don't know, and frankly don't care. It's really unimportant, why.Since speaking to MiniMax, I have also learned that the Hammer machine converts incoming single phase power to 3 phase for its 3-phase motors. I don't know what bearing that has on their telling me to bring in 3-conductors. Again, I don't care. It's unimportant. There's no need to justify it.I guess only "experts" know anything about electrical wiring, especially self-professed, "well-known electrical experts" who don't tolerate just any one "entering into an argument" with them - despite the fact that they don't know what a discussion is. Since I'm just a common, dumb-####, uneducated non-expert, with post graduate degrees including post doctoral, NOT in electrical engineering, I can't be expected to know anything about that field.It's funny Rick, in years of participating in this forum, I have never, EVER heard anyone else refer to himself as a "well-known expert," but you. And we DO have experts participating here. You are a legend in your own lunchtime.I have never before read anyone castigating another for daring to "enter into an argument" with him because he was a "well-known expert who has very great knowledge."Well, LA DE frickin' DA!And I thought that the fellow in the White House had the market on hubris!
I am sure the new combo will do the job for you. One thing I would like to clear up is what you were told about the Hammer motors. They are single phase and designed to run on 60 Hz AC. The Felder machines come standard with 3 phase motors and single phase in an option. The Felder machines with VFD do use 3 phase motors. Also, the MiniMax motors are rated at 4.8 HP because they are 50 Hz motors and when they run at 60 Hz they run faster thus a higher HP rating. Give us a report on your new combo when you get it.
Life is what happens to you when you're making other plans .
Thanks Jerry,Rich
Rich, I don’t understand what your personal issue is with this, but at no time in this discussion have I treated you the way that you have been treating me from almost the outset.
You started this discussion by asking why I didn’t advise people to run the Neutral wire. When I answered your question and explained that the Neutral wasn’t needed, you responded by progressively insulting me more and more with each new posting.
I don’t know why you are taking this so personally. You asked me a question and I answered it. Because you didn’t like the answer I gave, instead of discussing the facts, you chose to insult me as a method to win an argument.
Actually, this isn’t even an argument, because you haven’t even presented any information that can be argued or discussed. The only thing you have done is insult me, and say that you have a feeling. To date you have not substantiated any information about why the neutral is needed, and you even lied about the information you did present.
Up to this point, I have not responded in-kind to your lashing out, but I will state this observation that you will probably take as an insult (take it as you wish, but it is nonetheless my observation): In my experience, when a person resorts to personal attacks instead of presenting information, it is because that person does not have the knowledge or wherewithal to discuss the information necessary to make their point. It is a method of redirecting the discussion away from the facts, because that person cannot discuss the facts on their merits.
So I am putting this discussion back on track with a simple demand: Show me the tool that requires the Neutral! We’ve already heard from someone that owns the Hammer C3-31 that it doesn’t need the Neutral, so that is not going to work this time.
Furthermore, I can assure you that any tool that uses a VFD does not use the Neutral for the control circuitry. If you had done the homework that you claim you did, you would know that VFD’s don’t use the Neutral. I wouldn’t expect you to know this, but VFD’s don’t even use AC power at all. They rectify the incoming AC power to DC power, and then electronically create a 3-phase output from DC.
By the way, I am not just a self-professed expert. All you have to do is type my name in Google and you would know that I’m not just talking through my hat. The following quote came from a much larger forum than this one (other names withheld):
So, do you think you can try to address the facts here without launching a personal attack? Or are you just going to attack me again without actually discussing the topic? If you can't discuss the topic on its merits, then you need to stop providing electrical advise to others.
"Actually, this isn’t even an argument,"Well you've finally, finally gotten SOMEthing right.No, this is not an argument. That is what I have said repeatedly. I asked you a question, from that point on you accused me of arguing.I have made one point and ONLY one point. I have said, that in a NEW INSTALL, it is a smart thing to pull 3 conductors and a ground rather than just 2 conductors. I have never said that that any specific machine other than the Hammer (which I had on order, but didn't actually have in my possession) could use the third conductor. A 240 box with 2 hots and a neutral is a more versatile distribution, should that be needed.I think it is silly to install a NEW RUN of 240 and limit that to only 2 conductors. Got it?You apparently have a huge problem if anyone says anything even the slightest contrary to what you have handed down from the mount.Thank you for even more of your self-serving puffed-up self-importance. You are not JUST a self-professed expert, huh? Well why didn't you tell me in the first place!!? That changes everything!Not JUST a self-professed expert!Rick, your arrogance and hubris is known quite widely. Please DO make a Google search!Put a fork in this one Rick. The thread is quite finished. You may enjoy it all alone now.Rich
Edited 11/12/2006 5:30 pm ET by Rich14
Rich14 you wrote,
One comment about your 240 wiring scheme. Why don't you advise 3 conductors plus ground? (two hot, one common, one ground)
RC answered your question, the only thing he left out was to save money. You didn’t like his answer and said
It's just as easy, it costs little more, and it gives the opportunity to use the additional capability, should that become necessary.
Using your logic you should probably run 6/3 plus ground even though it’s a more money but you may need the extra capacity and capability some day.
Yes, the neutral wire carries current, to ground.
Actually this is false. In and AC circuit current flows alternately one directions and then the other direction (maybe that’s how it got it’s name). Current in the neutral wire flows half the time towards the load and half the time away from the load. It does not need to be tied to ground to work. The grounding is for safety. The neutral wire is not ground it is just reference to ground.
Since I'm just a common, dumb-####, uneducated non-expert, with post graduate degrees including post doctoral, NOT in electrical engineering, I can't be expected to know anything about that field.
Having a degree or multiple degrees does not make you and expert on every thing. I found that every thing RC said was factual and you can agree or disagree.
You complimented RC on his web site and the information available and then turned around and said he was wrong and you are going to take the advice of someone who doesn’t know what the machine needs but he agreed with you. By the way I’m glad you didn’t buy from him, I would never buy from someone who doesn’t know about the equipment that he’s selling
The guy demonstrating this machine also advised me to wire with 3 conductors. He was not sure about the machine needing that, but said that's the way he wired his shop.
Jack
Yes! Well said. I have found all of RC's statements to be factual. When he does'nt understand something he asks pertinent questions. Too bad some prevaricators try to sand bag him. He backs up his statements with formulas that one is free to verify, a valuable and appreciated source of knowledge on this forum IMHO. He does his homework and is not afraid to correct himself. Hard to ask anything more of a poster.
I tend to give the benefit of the doubt to posters such as he and to view the posts of those who mislead with great skepticsim.
Tell me the truth a few times and I will listen to what you have to say, lie to me once and it's a long hard road back to believeability.
A little off your message, but while I'm here, I don't consider it boastful to present one's bona fides.
You may be a Repuglican, Jack but you are my kind of people.
Don------------------------------------
The ultimate result of shielding men from the effects of folly is to fill the world with fools. -- Herbert Spencer (1891)
I’m trying to figure out what I have said or done in this thread to warrant your retorts, and in the process of re-reading this thread the only conclusion I have been able to come up with is that you are so single-tracked on your thoughts that you aren’t even paying attention to your own statements.
I have been very patient with you, but my patience has ended. (For this, I apologize to other readers of this thread.)
You did in fact start this discussion by arguing for the sake of arguing. You started your diatribe by contradicting Daryl, and progressed downhill from that point on. You lied for the sake of making your point, and you still have not justified the reason for lying. As a matter of fact, you dismissed your lie as something that was not important to the discussion.
The differnce is between knowing and just guessing. You were just guessing! The whole basis of your original premise was that you owned a tool that required the Neutral. So what difference did it make? It was a lie; and it was a lie that you tried to use to falsely make your point.
You have stated that wiring for the Neutral is “The Smart Thing to Do”, yet you cannot come up with a single woodworking tool that requires the Neutral. So please explain how this is so “smart” when there are no tools that require the neutral?
You think it is “silly” to wire a new circuit without the Neutral, when in fact you cannot point to a single tool that requires the neutral. So which is sillier, throwing away money that will never be used, or having proper knowledge beforehand?
I don’t care if the cost difference is just 5-cents for running the neutral or not. The fact is, is that it won’t be used, so there is no point behind it.
My question still stands! Show me the tool that uses the neutral!
If you can show me the tool that uses the neutral, then I will publicly apologize for contradicting you. If you cannot come up with that tool, then you need to shutup and stop providing electrical advise!
I am not happy with myself for making this posting, but I am human afterall, and my skin is only just so thick. I may regret making this posting in the morning but I have my limits, and tonight I have reached my limits. That being said, I apologize in advance to the other readers of this forum.
Edited 11/13/2006 5:44 am ET by RickChristopherson
I have read your posts and although I am not an electrician I know enough to respect your wisdom. I don't think you need to apologize to anyone unless it is to yourself. Unless you enjoy arguing, however, I think you're wasting your time trying to convince someone who refuses to learn and criticizes you for trying to answer his question. Believe me, this is not a criticism to you, only a suggestion
All: I'll tell you what to pull in a conduit for the future: a string. A nice ¼" or so string. Then if you need another wire you can pull it in with little trouble and all you have laid out is the cost of a piece of string. I've done it a million times.
Duke, retired electrician."... if people did not die so untidily, most men, and all women, would commit at least one murder in their lives." R. Kipling
RC, you are right to be put off by someone that thinks they know something and presents themselves as an expert. It diminishes the quality of advice that the true experts offer here. I was put off by he started talking about pulling a wire when anyone that had pulled one would know there was not place to connect it on this type of receptacle. You are more patient than I.Woody
It's obvious who knows what they're talking about in this thread. That said, I find it pretty amazing the webelves leave a thread like this up and running since the casual reader might not make it through all the posts and pick the wrong expert.
Kind of like Let's Make a Deal - "I'll take the electrical advice behind door number 3." You hope like hell that Carol Merrill is standing there in her leggy splendor beside a new Buick, but you might get Jay dressed up like a farmer holding a donkey by the reins.
I ordered the 5 HP ClearVue cyclone dust collector also. It has not
arrived. I have a subpanel in my garage that I get 220v for my 18" band
saw. I will be wiring up the 5 Hp motor soon. I would like to keep
in touch and see how you progress. I'm in Sacramento CA
I have a new Hammer K3 saw/shaper and I used the same wiring I used for the Unisaw. Are you really sure you needed the neutral conductor? Even the big Felder machines that are single phase only use two conductors with ground. My saw/shaper has two 4 hp motors, electronic control circuitry, motor braking and switching circuits for reversing the shaper motor and I use the same wiring that I used for the old Unisaw, 10/2 with ground.
I disagree that 3 conductors with ground should be used. All 5 of my shop machines only need 10/2 with ground, 3 conductors with ground is not necessary unless you are powering a clothes dryer or range.
Life is what happens to you when you're making other plans .
Jerry,
Hmmm. The instructions I got were for 3 wire. I'll check. Why does a clothes dryer or range need 3 wire?
BTW, how do you like the shaper? Mine is coming with a router spindle instead of the standard shaper spindle. Do you have the new Felder dado head for the saw? Which outrigger did you get. I've got the "Comfort" package.
Rich
Rich14, a dryer needs the neutral because of the 120 v motor. A range needs 120 volts because of the controls and lights. You will probably have a 3 wire pigtail coming out of the saw like I did, two hots and a ground connection are all that is needed.
The shaper is excellent with the tilting spindle and 4 HP motor with 4 speeds. I have a Bench Dog router table wing mounted on my Delta heavy duty shaper. I am going to keep the Delta shaper and use it with my many 3/4' cutters. I will use the K3 shaper for heavy duty work using 1", 1 1/4" and 30MM cutters.
I did get the dado option but I did not get the Comfort package. I wanted a smaller saw as I rarely process sheet goods. I may regret getting the Comfort package, but so far I am happy with my decision.
Life is what happens to you when you're making other plans .
I have hardly ever needed to handle sheet goods and have never really needed a shaper. I got this machine as part of a large home remodel project. There will be lots of cabinet construction and I'll need to handle sheet goods a lot. That's why I got the comfort package. A sliding table saw's ability to cut panels very accurately really impressed me. It's amazing how much more accurately (squareness and size) it cuts compared to pushing sheet goods across a cast iron table against a rip fence on a standard table saw. The errors really add up in multiple cabinet alignment. I'm really looking forward to using this machine.
Sorry to pull this thread off topic.
Rich
You made the right choice getting the comfort package. This saw is light years ahead of the typical cabinet saw. As was brought up in another discussion on this board, how smart is it to be pushing a board toward a spinning blade. A slider is much safer and more accurate. On more thing, I never used my Unisaw blade guard but on the Hammer I have yet to remove it. If I do need to remove it for a special cut it comes off in 10 seconds. The blade guard is not obstructive and I feel better protected when using this saw.
Life is what happens to you when you're making other plans .
A cloths dryer needs 3 wire because it needs both 240 and 120. 240 for the heater and 120 for the controls and the motor. For 240 you only need the 2 wires plus for safety the ground wire.
The common wire can be dangerous if there is a faulty ground connectiom to your panel, something that happens frequently in this universe. The lenth of wire from the utility transformer to your house has resistance so the common in your panel may not be at ground potential if there is a faulty or missing ground.
Jack
Edited 11/8/2006 6:16 pm ET by JLMCDANIEL
Edited 11/8/2006 6:18 pm ET by JLMCDANIEL
I think your statement that keeping one hand behind you while you're wiring will keep you safe could be misleading. Can you set me straight? I am wiring this panel barefoot in my damp basement floor. Can I really touch a hot wire without a shock?
"I think your statement that keeping one hand behind you while you're wiring will keep you safe could be misleading. Can you set me straight? I am wiring this panel barefoot in my damp basement floor. Can I really touch a hot wire without a shock?"
It is perfectly safe. After a second or two you won't feel a thing....
You should use both hands to ensure all the current goes through the heart.
Ideally, this should be accomplished before the person in question reproduces.------------------------------------
The ultimate result of shielding men from the effects of folly is to fill the world with fools. -- Herbert Spencer (1891)
Having been hit by 110 and 220 numerous times, I can testify that while 220 hurts a bit more it is not automatically lethal.
John W.
Having an acquaintance, that worked for the power company, getting hit twice with 17,500 volts during his career with nothing worse that a broken ankle from jumping from the power pole, I would say that even at that voltage is not necessarily lethal.
What I learned was "volts kick; amps kill"
If a metal box is used, it must be grounded, which is why I used 10-3wg.
Edited 11/14/2006 4:59 pm by t_mauery
You were responding to my earlier post in which I said the following:
However, I am very concerned about what you are suggesting in your posting. Please correct me if I have misread or misinterpreted your intent.
You are correct that a metal junction box needs to be grounded, but you cannot use the white conductor for this purpose. As per Article 310-12 of the NEC (and ref 250-119), the grounding conductor must be bare, green, or green with a yellow stripe. The same article also specifies that the "grounded" conductor (aka the Neutral) must be white or natural grey. The same article further specifies that the "Ungrounded" (aka hot wires) are Not of these colors. (I will try to ammend my original posting to reflect this last statement.)
The importance of what is stated above is that your 10/3 cable does not specifically address the need to ground a metal junction box. When you are working with metal junction boxes, you need to pigtail the ground wires such that the device (aka outlet) is grounded and also the box. I would suggest using the special green wire nuts which have a hole in the crown which permits the same incoming ground wire to extend past the wire nut and connect to the grounding lug of the junction box.
Hi Mr. O, long time listener, first time caller...After reading through this whole mess (which has some very good advice mixed in with some "expert advice" so be careful), I have some very simple pieces of advice. 1) No matter what you do, NEVER wire a 240 Volt circuit into a "standard" NEMA 5 outlet (what you find virtually everywhere in your home). I worked with a crew that jacked into a NEMA 5-20 outlet in a workshop to do some demolition & construction work. Little did we know that some -insert your own expletive here- jerk had decided to wire that 120 volt outlet up to power his 240 volt 20 gallon air compressor. To make a long story short, your tools work EXTREMELY well for about 10-30 seconds... until they let out that magical tool smoke.2) If it's in a workshop or garage, your 110 volt outlets and certain 240 volt outlets & tools should be protected with GFCI outlets. If a given tool continuously trips your GFCI breaker, first read the manual to make sure there isn't a reason mentioned in the manual, if there is no mention something isn't right, discontinue use of that tool until it is serviced or replace it. Arc-fault breakers are also a good idea if you are going to be making heavy usage of extension cords on a given circuit.3) Always use commercial-grade outlets. It isn't worth "saving" the money today when at some point down the road your tools won't stay plugged into the outlet any more if you use the cheaper (not just less expensive) residential grade outlets. Not only is this a nuisance, but it is a severe safety hazard. Loose connections have higher resistance, which leads to heat & ultimately failure &/or fire. I've seen the plastic melt off of loose plugs before. Not good. The commercial grade outlets are made with heavier and more resilient conductors and bodies, a combination that will allow the outlets to hold onto plugs for 10's of years into the future, almost regardless of how often you plug & unplug your tools.4) Unless it has electronic controls, you don't need 3+1 wire in your shop for anything but the 3 or 4-way switches. If you feel the need to run a 3+1 conductor cable in your shop, do yourself a favor and spend the extra money on running 10-3 to a two or three gang box with a 30 amp 2-pole breaker. There, you can install your 240 volt outlet (USE A DIFFERENT COLOR OF OUTLET) and one or two 120 volt 5-20 outlets in the same box. If you install two 120 volt outlets, you should wire one to each pole of the breaker. DO NOT do this where you will be using the 240 volt line to it's capacity, which really isn't that often in home shops. This will allow you a great deal of freedom with your tools down the road and won't lock your shop into today's configuration. It will also allow you to have a shop-vac plugged in conveniently next to to you 240 volt tool without draping extension cords across your shop.Another feature I am a huge fan of is installing power drops from the ceiling to power your tools. It prevents tripping hazards and allows greater shop flexibility. When doing this it is prudent to run 10-3 w/ground on a 20 AMP 2-pole breaker per drop. At each drop location, install a 3+1 twist-lock outlet facing the floor. Now, depending on how you wire the twist lock plugs (make CERTAIN that you use strain relief plugs and get the conductors wired right), you can either power your 240 volt tool(s), or you can power a 2-gang box with 2 120 volt GFCI outlets, each on its own circuit. Flip breaker when not in use.5) All of these wire size charts that I see floating around are great, but they fail to take the wire TYPE into account. There are over 10 different flavors of wire insulation and two different conductor materials available. There are also several different types of sheathing available for a cable (A cable is more than two separate conductors combined into a single flexible sheathing. Romex and extension cords are 2 types of cable.) That said, every combination of conductor, insulation & sheathing has the potential to have a different current carrying capacity. Unless you are POSITIVE that you have the right rating for your cable, look it up of consult a qualified electrician.6) Lastly, it takes more of a man to call an electrician to get help with a job or question than it does to do something stupid out of ignorance and burn a shop or home down. Let's face it. More DIY'ers than electricians will "complete" a wiring job that burns down a shop or home. I certainly hope this didn't offend anyone, but if your giving advice on the juice, make sure it's right. If any of the things above are not to NEC, let me know and don't duplicate my errors.
Edited 11/16/2006 1:08 am ET by Mr. B
Just out of curiosity, why the call for 10-3wg? Isn't 12ga enough for a 20A breaker?
You are correct in that statement that a 12-3 w/ground would be most appropriate if you were never going to exceed a 20 amp load. I prefer to oversize any wire I put in a shop since you never know where there may be a point load down the road. It just prevents the hassles of rewiring down the road.Also, since more people use that setup with the 2-gang box with 2 outlets on separate lines, putting in the 20 amp breaker prevents people from doing anything stupid by overloading the circuit. This setup would allow you to upgrade a breaker down the road to power two 15 AMP 240 volt tools from one line, or an one insanely large 30 amp tool (think 7200 watts, like a water heater), whereas the 12 gauge wire is instantly over-loaded under the same configuration.Lastly, this is a forum full of people of all walks. I hesitate to give advice that leaves the in wall or above-ceiling wire as the weak link. Take care!
Mr. B,
Thank you for your reply/thoughts on the matter. All of your reasons seem to make excellent sense.
Mr.b and Mr.Christopherson,
I have a question about GFCI outlets. My understanding is that they trip if there is a tiny diference in the current flow between the hot and neutral. If this is the case, and the nature of a capacitor is to absord current and delay the output, wouldn't and capacitive start or capacitive start, capacitive run motor cause the GFCI to trip?
Jack
I've never run into problems with that, but individual results may vary.Regardless of the presence of a cap, you still have voltage out and voltage back in. My understanding of a GFCI leads me to believe that this would only be a problem if you were -leaking- current out of a circuit to ground or another large conductive body, such as a human body. The only tool I've had that routinely kicked a GFCI breaker is a stationary belt sander that got metal powder in the motor. Rick, what are your thoughts on this?
Your concerns are correct and well justified. This is the reason why it is easy to receive an exemption for installing a GFCI on a circuit that would otherwise require it.Just FYI because it was recent, but last night I saw an episode of the CSI TV show where a worker was supposedly killed because the ground prong from a tool was removed, and the show falsely presented this as a failure mode for a GFCI device. This is not how GFCI’s function, as you have already correctly stated. As a matter of fact, the greatest value of a GFCI is for older homes where there is no proper grounding system because they will still provide protection where it did not otherwise exist.Yes, GFCI’s are based on a differential amplifier which detects a difference between two signals. Because this type of amplifier design is naturally unstable, even the slightest difference between the two signals will cause the amplifier to slam to its limits. To that end, the GFCI detects minute differences between the two “current carrying conductors” feeding the circuit. And contrary to the CSI TV show, it has nothing to do with the ground wire.The basic concept is that if the current flowing through one wire is not identical to the return current in the other wire, that some of that current went where it wasn’t supposed to go. The assumption is that if the same amount of current didn’t return to the source, then it went to a ground, which may have been through a person’s body.Because inductors and capacitors store energy for short periods of time, the super-sensitive amplifier will see this as a ground-fault because for a split-second you are either charging or discharging the storage device (just like a battery, but on a faster scale). For this reason putting a motor (which is an inductor plus its start capacitors) on a GFCI protected circuit may cause an excessive amount of nuisance trips. Early GFCI’s were exceptionally prone to nuisance trips from motors, but I believe that more modern and intelligent GFCI’s can detect when the cause of the imbalance is due to inductive or capacitive delays.
Thanks for your reply. My AC electrical training was pre GFCI and not used on the equipment I worked on the last 30 years.
Jack
I did some research on the residential applications for GFCI and...You can get motor-rated GFCI modules such as the ones available through P&S at http://www.passandseymour.com/products/product.html?s=164&mkt=3 If I'm not mistaken, most of the dead-front (no outlets, just a GFCI pass-through device that fits in a decorator faceplate) devices are rated for motor control.That said, they are only rated through a horse & a half.Thinking back through my own experiences, I have operated a pedestal drill press and a table saw off of a 20A GFCI breaker before. Both were capacitor start, but both fit within a 1.5 horse envelope, too. Theoretically speaking, if you ensure that a larger tool is totally grounded by bonding all metal parts to ground, there should be no possibility of electrocution from that tool. That said, if you are touching bare metal on the well grounded tool and come into contact with a current source like a frayed cord, your odds of survival are less than great. Well-grounded tools are still my preferred method of protection as I hesitate to trust an electronic device on its own.Now, on the commercial/industrial side of the coin, you can get larger GFCI breakers and relays that are made to protect equipment, but their cut-out threshold exceeds the 8mA that can cause death, so I was really hesitant to throw those into this discussion.Regardless of all of this, as long as you at least abide by the NEC and you'll be in good shape. Just keep in mind that the NEC is a guide that delineates minimum standards. You are always free to exceed them, as I often do, just don't go running a 50 Amp line using 1000MCM wire to your home shop (I'd love to see someone try that. Haha!) or I'll have to laugh at you.
Just keep in mind that the NEC is a guide that delineates minimum standards.
Although it may be the minimum required standards it has a very large safety margin built in. If I remember correctly 12 ga. copper wire is rated at about 43amps and NEC restricts it use to 20 amps.
Jack
No offense intended, but you are mostly incorrect in that statement. Yes, wire will carry a good deal more current than rated for, but only under ideal conditions in a vacuum or open air. Since ideal conditions don't exist outside of laboratory or assembly-line conditions, they derate the wire accordingly. As amperage increases in a conductor, its temperature rises. That's a problem when you're dealing with a wire stapled to a combustible material then buried under insulation.If you run your wire in conduit, after you get a certain number of wires in the tube, you get to derate the wire to accommodate the loss of the ability to dissipate heat. Manufacturing processes are not perfect either. I have pulled wire off of the shelf at the Home Depot that ends up having a dead short to ground from the get-go. I'm sure that's also a consideration.For those reasons and many more, that is why the NEC derates the actual absolute capacity of a wire down to a more applicable value. You just can't predict all of the real-world variables.Personally, I am a lot more comfortable know I've "over-wired" on a project than knowing I wired to meet a minimum. It definitely costs more, but the extra dollars are ultimately worth the peace of mind now and down the road.
Mr.B
Not to be argumentative but I don't believe I am wrong. The amperage rating of wire and the transmission rating are two different things. To give an example to run the power to a hot water heater you use 10/2 +ground but the wiring inside the tank cover to the heaters and controls are either 18 or 16ga. The same current requirement in both places. There is a big difference between wire rating and code.
If you use NEC you are already over sizing the wires. They have a large safety margin built into their specs which takes into account wire resistance, voltage drops, and current flow in the most adverse conditions. Of course you should wire to those standards to meet code and fire regs, but going above them is a waste of money and resources because of their built in safety margin
Jack
Added: Be sure to check message 66
Edited 11/19/2006 2:06 am ET by JLMCDANIEL
Here's a link to a chart showing wire gauge vs. current capacity from the Alpha Cable catalog: http://www.alphawire.com/PAGES/383.CFM
As an example, 12 AWG is good for anywhere from 36 to 55 amps (depending on the insulation) for a single wire in free air at 30 degrees C ambient temp, but as you mentioned this isn't the same as the NEC requirements.
That's exactly what I was talking about. I designed control interfaces between computers and high voltage AC for over 20 years. We always use a much smaller wire inside the interfaces than what they were wired to.
Jack
Evening Rick...
I think I just caught something in this post that I may not be aware of and would like clarification. I will explain my set-up I just wired for 220V to give you as clear a picture as possible.
220V.. I used 10/2 to the outlet as at one time I had a MM 16 on order that draws 21.8 amp. Plans were for 30A breaker at box and 30A outlet. The BS that ended up in it's place is 220V but only draws around 11A. No problem so far as the run is about 38 feet and the 10 gauge will get er done nicely with 20A commercial breaker and outlet. The outlet is a twist lock so I cut off the machine plug that it came equipped with and replaced it with the needed 3 prong heavy twist type plug rated 20A to match the 20 A breaker, 20 A outlet. That's the set-up.. but here's the question that arose from your post.
Coming from the back wall of the shop where my main box is, I have made 5... 90 degree turns (walls and ceiling where the rubber sheathed 10/2 has also been sheathed in outdoor rubber armour with that stiff 10/2 and secured overhead.. overkill as all is inside but my nature). The 90 degree turns are accomplished by use of metal junction boxes where all color wires are nutted to appropriate continueing color wires to move forward.
From what I gathered, not only should they be color connected and nutted as necessary to have a continuos circuit from A to Z.. but should the ground wire at each of the 5 junction boxes have an additional piggy-tail of the naked green ground wire coming off the green nut and secured to a ground nut in each junction box?? Should an additional green ground piggy be used again at end of line at the metal outlet box that grounds it to the outlet box itself along with the normal green ground that attaches to the standard outlet ground connectorf?
Hopefully I have made my set-up clear. Your advice would be appreciated as if I understood the post correctly.. I don't have the entire package properly grounded at this point and if that's true.. it will be by tomorrow night before that 220 V line is used again! :>)
Regards...
SARGE..
Sarge, Do you mean to say that you have the wire in conduit? Or are you saying you spliced together several shorter sections of 10 gauge?To answer the question, yes, any metal box in any circuit should be securely grounded. That can be accomplished in several ways, such as attaching the ground wire to a screw in the bottom of the box, or attaching the ground wire to the back strap on an outlet or switch (that has been APPROVED for such a use) and then making sure the screws are all tight.This way, if anything goes wrong in that box, you find out by having a breaker trip in stead of finding out by touching a box charged with 110 or or more volts.
See post #63 Mr. B....
Regards...
SARGE..
If I understand you correctly, you are using romex type cable inside of a non-metalic conduit, but used metalic junction boxes at the corners. Correct?I am not entirely confident in my answer, but based on a quick search it would appear that those metal enclosures should be grounded. I couldn't find any exceptions that would be applicable.However, this isn't a situation where you should panic and shut down the shop until it is corrected, especially if the boxes are out of reach. Because these are splice boxes, you may be able to simply loop one of the ground wires around the grounding lug that should be present in the bottom of the box. This way you don't need to remove the existing wire nuts.
Rick & Mr. B...
Actually I have used 10/2 rubber sheathed which is sufficient, then threaded that through 1/2" rubber conduit (water-proof as used underground). This runs exposed on the back wall up from the connection at the main box up to the ceiling and takes a 90 degree turn along the ceiling to a metal junction box. From that junction it takes a 90 degree and down the ceiling of the length of the shop for around 22' to another metal juntion box. At that box it turns 90 degrees back toward the center of the shop to another junction box, then down a metal center support to the outlet itself.
So yes... I have spliced the 30' + feet in sections at each junction box by nutting red-red hot.. black-black hot.. green-green ground together. What I have not done at each box is place an additional green ground from that individual green ground connection to a grounded screw at each individual junction. Nor a green ground to the metal box screw at the end of line at the outlet itself.
In essense ...the green ground wire at the outlet is only attached to the green ground connector on the outlet recepticle itself! The green ground wires at each mid-point of the run that are spliced in the metal junction box are continous and do not have an additioanal green on them actually connected to a metal ground screw in that given junction!
Here's a pic of the run.... thanks in advance guys as if I need to do it all the run is exposed and just a matter of taking the face plate off each junction and adding a 4" or so bare green gound from the current green nutting to the screw in the bottom of each box. Won't take but about and hour to strip.. undo the current two wires in that green and add a 3rd piggy-tail off it to the ground screw in each junction box as I intentionally gave myself excess in my original wiring scheme.
Regards...
SARGE..
Thanks for your detailed reply. I've printed out your message and the info from your website and look forward to reviewing it tonight. - Lyptus
Thanks for posting that and your web site. I had always wondered how people came to the conclusion that a motor that uses 2400 watts at 240vac would run cooler than a motor that uses 2400 watts at 120vac.
Jack
Rick,
I'm pulling stranded #12 wire through pvc conduit for my shop. 2 questions.1) About the white wire in 12/2 going to a 220 outlet you wrote:
"New Edit:Because of another question later in this thread, I have confirmed that code does specifically require you to re-identify the wire in some way."
Since I'm pulling single wires, should I use black for both conductors to a 220 outlet, or one black plus one white with black tape markings?2) I'm using stranded wire because it is easier to pull. Should I tin the ends before connecting to devices?Thanks.
Since both methods are permitted regarding the color of the wires, it is entirely up to you. Which color did you buy more of? Use that.There are two types of stranded wire, a fine strand with a lot of strands, and a coarse strand with only a few strands. The fine strand is good for extension cords, but not the best choice for permanent wiring. I couldn't find anything preventing you from using any type of strand, but the coarse will be easier at the connection points. The problem with the fine strand is that it is easy to have stray strands stick out from a screw lug.If it is coarse strand, I wouldn't tin the ends. I couldn't find anything specifically requiring or prohibiting tinning the ends, but if you use the fine strand, you may want to tin the ends at screw lug connections to reduce the likelihood of stray strands contacting undesired materials.
Thanks for the help. The wire is coarse stranded - intended for permanent wiring. Nevertheless, it still splays out a bit under screw heads, though not enough to come in contact with anything it shouldn't.
Again, thanks,
David
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