Should I run my bandsaw at 110v or 220v?
tablesaw635
| Posted in Power Tools and Machinery on
Hi all-
I just picked up a new old bandsaw, a 16″ Wallace from the early 50’s. It is a real beaut, and it runs really well considering it hasn’t been tuned up in ages. The motor can be set up to run on 110v or 220v, and I’m wondering what the pros and cons of these setups are. Currently it is wired for 110v, so that’s how I’m using it, but I have 220 in the shop which I have other machines on.
Thanks in advance,
Replies
Some years ago, I rewired all of my 110v machines for 220v. they start faster, run cooler, and work harder - and, you don't get that momentary light dimming effect that also makes the TV flicker as you start up one of those amp-sucking one or two horsepower jobs.
Assuming the 110 and 220 circuits are both adequately wired, it doesn't make any difference to the motor which one it is configured for. When wired for 110, the two windings are hooked up in parallet; when wired for 220, the windings are in series. Either way each winding has 110V across it; it doesn't matter.
However, since twice the amps are drawn on a 110 configuration, the wiring on a 110 needs to be heavier gauge. If the choice is between operation on a dedicated 220 circuit, and just plugging into an existing 110 circuit, the 110 is more likely to be inadequate. This gives rise to the often expressed opinion that motors run better when wired for 220. But a good, dedicated 110 will work just as well.
After digging into my old power engineering books, I see that BarryO is right about the windings, at least in common induction motors. However, at startup, the higher EMF of a 220V wired motor will result in less momentary Hysteresis losses, giving a slightly faster startup up time (slightly more torque). This is normally not enough of a difference to make a hoot cause no one starts up woodworking tools against a load. But since a 220V wired motor is pulling 1/2 the current from the source, there will be 1/4 the power loss in a 220V line (I squared R). If the line is properly sized for 110V, then no problem during runnning. Realize that during startup, the inrush current can momentarily reach up to 2X the normal running current. This further increases the line losses, but just during startup. For non-commercial shops, i don't think there is enough of a difference to be of any concern, as long as the line is properly sized, insulated, and grounded. Oh yeah, make sure the switch and outlets are also designed for 220V if using that voltage. It's not just a simple matter of changing the winding configuration in the motor - there are other things to consider.
PlaneWood by Mike_in_KatyPlaneWood
110 or 220.. Been around the block on this a few times haven't we. I've talked to a lot of folks in the business about it lately and they all say go 220 all the way because it will save the motors and you'll lower your electric bills. With my limited knowledge of electron theroy, I can believe both to a certain extent but not as much as is boasted.
I run everything on dedicated 20A/110V circuits that are homeruns back to the breaker box. I don't have a means of comparing the differences. I've never had a problem with any of my tools running on 110 so I can't justify the cost of rewiring the shop for 220. I have a lot of equipment because I am a tool junkie but I don't do woodworking for a living. These are my only hard case reasons for not switching to 220.Steve - in Northern California
If the doctor says you have Attention Deficit Disorder, do you pay attention to him?
how will running on 220 lower your power bills?
Using 220 might lower the electric bills due to 110v wires being under sized for near the limit use. Most 110 circuits "expect" and are wired for, at most, hair dryers, TVs, coffee makers etc. When you plug in your new fat table saw rated at 110v, 15amp normal running. You get some volt drop and as the same power is required ( VxI=W) up goes the amps and starts to heat up the wire. Heating the wire uses power or rather wastes it. The same size wire using 220v requires half the amps so the wire stays cool and less power is wasted. A prime example is a compressor rated at 15 amp. if you don't plug in near the CB board then the circuit breaker pops or the motor runs slow and gets hot.
Running the saw at 220V will lower your bill, but not by a whole lot. The difference comes in the line losses. Remember that there is some resistance in copper wire, so there is power dissipated in the wire (proportional to I squared times R).
Let's say your tool draws 20 amps at 120V and 10amps at 240V, and the distance from the breaker box to the saw is 50 feet (for 100 feet round trip back to the breaker box)
At 10 Amps, I would use #14 wire, with a resistance of .00297ohms/foot. So the total resistance is .297ohm. Power loss = I^2 x R = 29.7watts. If you use the saw 20 hours a month, that comes to 594 watts. So you've used about 6/10 of a kilowatt hour.
At 20 Amps, I would use#10 wire, with a resistance of .00118ohms/foot(note that the lower resistance will partly offset the higher amperage). So the total resistance is .118ohm. Power loss = I^2 x R = 47.2 watts. If you use the saw 20 hours a month, that comes to 944 watts. So you've used about a kilowatt hour.
In other words, you save pennies per month by using higher voltage. So your friends who say you save money by converting to 220 are right, although it will take 100 years to make up for the electrician!! That said, I would use 220 myself becuase lower current means less heat in the motor and better starting.
Hope I've been able to help.
PS I got my ratings and resistances off the internet. I don't trust the internet for electrical advice, neither should you!
When people 100 years from now see my work, they'll know I cared. --Matt Mulka
I hope Chris will forgive me for jumping in here with another electrical question :)
My Jet contractor's saw is currently (so to speak) wired for 110. The 230 has to wait until I can move the 230 receptacle out of its inaccessible corner. The motor plate lists 19 amps at 115 volts, and it's a new motor. It's on a 20-amp circuit that I don't plug anything else into. That circuit trips every 3rd or 4th time I start the saw.
Two questions: is this normal (e.g., perhaps the start-up amperage is higher than 20 amps?) and -- if the wiring to that receptacle will support it, can I replace the 20-amp 110 breaker with a 30-amp 110 breaker?
Also, I had to replace the power cord to the saw, so I replaced with with a 12-foot, 12-gauge wire, but I noticed the plug is only a 15 amp plug. What's the significance of the rating on the plug?
I would say a 19 amp load should not trip the breaker on start up. That 20 amp rating is continuous duty. For a brief start up period exceeding 20 amps should be fine (I think there was a thread on this before). Also are you certain the saw is the only load on the breaker? Could be there is something you are unaware of attached to that line. I'm not sure what the difference is between 15 and 20 amp plugs, but you should probably ask an electrician which one to use. More importantly, have one look at the circuit to see why it's tripping. Most importantly, never listen to electrical advice from the internet :) Have an electrician take a look and know the work is done right.
Hope this helps.
When people 100 years from now see my work, they'll know I cared. --Matt Mulka
Edited 4/2/2002 12:42:47 AM ET by Matt Mulka
Forest Girl, It may be your wire is a bit on the little size. Check the gauge of the wire, it may be too small.
Circuit breakers are mechanical devices, they can go bad over time.
f_g, First let me preface this with very strong warning:
I'm not an electrician and I caution against using any of my suggestions without first consulting with an electrician.
You should not be tripping a 20 amp breaker with your saw running on 110. I run mine on it all the time and only blew the breaker once. However, that I attributed to the fact the I blew sawdust into the motor when I was cleaning it. It's been fine ever since.
In order to upgrade to a 30amp circuit, you will need to change your plugs, outlets and most importantly, your wiring to that which is rated for 30 amps.
I don't know all the particulars but I might suggest that if you are using an extension cord, make sure it is rated for 20 amps and that it is no longer than 25'. Ideally what you want is a wire length between the saw and the breaker of no more than 50', the shorter the better. You also want to make sure that the wire size is as equal as possible from the saw to the breaker.
To the best of my knowledge, the house/shop wire size for a 15 amp circuit with 4 dual outlets is 14/2. A 20 amp circuit would require 12/2. Your electrican will know for sure.
Hope this helpsSteve - in Northern California
If the doctor says you have Attention Deficit Disorder, do you pay attention to him?
Hey, we meet again. The reason I changed the power cord out was so I didn't need an extension cord. I think the power cord is 10' or 12' long, 12 ga, so it should be fine, no?
With regard to the equal-size issue, the only change would be that from the saw switch to the motor the Jet cord is 14 ga., assuming the circuit is 12 ga (see next paragraph).
The distance saw-to-breaker is probably less than 25'. I can't see anything on the circuit wiring that shows guage (or anything else for that matter), but I think it's 12 -- an electrician installed the subpanel several years ago, and it has all 20-amp breakers except for the 230V circuit.
Question: Why does jet put a 14 ga cord on a motor that pre-wired for 115 V, and therefore 19 amps??????? I don't understand this!
That's a 1.5 HP motor, which is about the biggest that runs on 115V. So everything must be just right. Execessive voltage drop will cause a brownout condition at the motor, which will cause it to draw too much current.
The use of extension cords usually causes this problem. Also, loose wiring connections can also cause it. Also check that the wire guage in the circuit is 12AWG. With a 20A breaker, it should be, but you never know.
You could also try shortening the power cord, or going to 10AWG.
The plug and the socket really should both be 20A. Perhaps you're getting voltage across the existing 15A ones, although I doubt it unless the socket is loose.
You can only put a 30A breaker on a dedicated circuit that serves a 30A socket. The branch wiring must be 10AWG, as well as the plug and power cord.
Hi Barry, thanks! My reply to Steve addresses the supply cord issues. I'll check the outlet to make sure it's in good shape and 20A. I didn't quite understand the following from your post: "Perhaps you're getting voltage across the existing 15A ones, although I doubt it unless the socket is loose." Did you mean "voltage drop"?
The problem I've found with trying to use 20A plugs is that they don't seem to come in a "normal" 3-prong configuration -- they have one weird horizontal prong.
Please see my question about 14ga wire on these motors and chip in your opinion (in my reply to Steve).
Yes, I meant "voltage drop".
BTW, the reason 20A plugs have weird horizontal prong is so that they'll only plug into 20A sockets. Actually, 20A sockets are combination 15A/20A sockets, with a "T"-shaped left slot, so either 15A or 20A plugs can be connected.
f_g, realizing now that your outlet to motor distance is fairly short. Did the original cord on the motor have a 20amp plug or just a standard 15amp plug. Mine has a standard 15amp plug and before I ran the new 20amp circuits I ran it off a 15amp circuit and just put up with the lights dimming on startup. O.K. so now you're really mad.... Sorry, jealousy will get you no where my dear.
Really, it makes no sense to me why you are blowing circuit breakers unless your saw is starting under a heavier load than normal. I don't want to start you off in a whole new direction but does the motor still blow the breaker if you take the belt off..
Steve - in Northern California
If the doctor says you have Attention Deficit Disorder, do you pay attention to him?
Edited 4/3/2002 2:12:09 PM ET by Steve Schefer
Edited 4/3/2002 2:12:59 PM ET by Steve Schefer
Forest Girl you have the same problem i had when I pluged in my new Dewalt 746 table saw. No tripping but the lights would dim and the motor would take a few seconds to get up to speed. This all on a single socket 115volt 20 amp line #12 wire 20' from the breaker panel + 2 shop lights. Changed it over to 230volt and the change is almost magic, instant to running speed and no dimming lights.
Hi Nigelusa, yes, I can believe it! The 230V is on my list of things to do, but a few notches down. It's moving up the list rapidly, though, with these hassles! I'm thinking now, though, that I need to make sure there is nothing wrong with this particular 115V circuit anyway.
Did you say you had a 220v socket in the corner? Why not make up an extension lead for temp use until you get around to moving/adding the socket to a better place.
The 220 wiring ends in a closed box, no receptacle yet, and I'm not quite up to wiring one yet! That corner is really crammed with (someone else's) stuff, so what I want to do is keep going from that box, about 8 feet down the wall to get to a more accessible place, and mount the 220 receptacle there.
One thing I can't figure out is why the electrician ran cable with a white wire to the 220 box (red, black, white and ground). I thought you didn't need a that white wire with 220. The local hardware store guy told me to just double it over and tape it.
He ran the white wire because its required now even if its not used this time. Some "220v" machines run the motors on 220v but the control equipment is run on 110v. This is very true of three phase machines. Using the bare grounding wire as the neutral is very poor practice. The bare grounding wire is a safety wire in case of a short. You should install a four pin socket on the wall. Red, black, white and ground ( called earth in the UK) and use a four pin plug on the table saw with out the neutral used. Make sure the wire is protected from mechical damage. i.e. when draging plywood around etc.
Thanks! It turns out that the sub-panel in the shop is only 40 amps, so I'm going to have to get this conversion done before I add too much in the way of simultaneously-used equipment.
How many machines do you run at once? 40 amps is plenty of power. Just make sure the lights are on their own breaker. What else do you have that needs more power than the table saw?
The only other significant things would be a dust collector and air filter (which aren't purchased yet, so still moot). I suppose the little air compressor might be rude enough to kick in while the tablesaw running. And then there's the coffepot and the stereo :-) The lights are on a separate circuit, so that's OK, but I will need to keep track of the load as I add fixtures.
I'm not really concerned about the 40A total -- I had just thought originally that it was 60A.
Thanks!forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
The white wire is NOT required for 220V service, and is not needed for your table saw.
If you install a 3-conductor 220V receptcle, the HW store guy is (almost) correct; just put a wirenut over the unused while conductor (better than taping).
However, having the white conductor there gives you flexibility. You could install a 4-conductor 220/110 receptacle, if you had a piece of equipment that needed it. Kitchen ranges are an example. It used to be permissible to do this with a 3-conductor receptable, hooking the neutral to the equipment ground(!), but this is now prohibited.
Or you could install outlets on two separate 110V circuits, which share a common neutral conductor (this works because the 2 hot conductors are out of phase).
Hi Barry, thanks! OK, I was with you pretty well 'til the last paragraph. But wait! Maybe I understand that one too. Ooops, maybe not.
Keeping in mind I'm not going to try this, I'm simply curious to understand: The 2 hot conductors you speak of are the hot wires from the 220 circuit, yes? So, are you saying that I could use each of the hots to set up a 110 outlet, the white being common neutral? But they'd be controlled by the same circuit breaker, wouldn't they? Or does each of those hots go to a different breaker (I didn't look before I started this rumination). What about the ground, in this instance?
What you said about the white wire and the 110/220 etc. makes sense, and helps me understand what my DIY electrical book was saying too.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Keeping in mind I'm not going to try this, I'm simply curious to understand: The 2 hot conductors you speak of are the hot wires from the 220 circuit, yes?
Yes
So, are you saying that I could use each of the hots to set up a 110 outlet, the white being common neutral?
Yes.
But they'd be controlled by the same circuit breaker, wouldn't they? Or does each of those hots go to a different breaker (I didn't look before I started this rumination).
It's best to use a dual breaker for this. If you supply any 220V equipment, then you have to. If you're only supplying 110V equipment, you can use 2 individual breakers from an overcurrent protection perspective, but using the dual breaker fullfills the requirement for providing a means for switching off both hots simultaneously.
What about the ground, in this instance?
still need a ground, as always. Either a bare or green wire, or the conduit itself if non-flexible metallic.
So, are you saying that I could use each of the hots to set up a 110 outlet, the white being common neutral?
I just want to make sure that you meant to say you could use each of the hots to create two separate 110 outlets using a common neutral and common ground.Steve - in Northern California
Thanks Barry!
f_g, I should have posted this for you:
So, are you saying that I could use each of the hots to set up a 110 outlet, the white being common neutral?
I just want to make sure that you meant to say you could use each of the hots to create two separate 110 outlets using a common neutral and common ground.
On a standard 15 amp 110 circuit I've been told that the norm is a max of four 110 duplex outlets on a single run. Thats the norm for household appliances but probably not in the shop.
Steve - in Northern California
Edited 4/17/2002 4:50:12 PM ET by Steve Schefer
Hi Steve, how'z things??
Yes, more precisely, it would be 2 outlets. There might be another possibility though, that of having one outlet with its 2 receptacles on separate poles of the 220V. Would this work? Isn't this essentially having 2 different circuits for that 2-receptacle outlet? I'm trying to wrap my brain around this electrical stuff, but it's a s-t-r-e-t-c-h!!
As an aside (the two of us must interject asides in our conversations, ya think?) I got an old bookcase transformed into a rolling lumber rack, finished it this morning. Now, when I need a small piece of wood, I actually know where to look for it! It has pieces of 1x, 2x, moulding, dowels, scrap oak and maple, and a handful of 1x12 and 1x10 cedar boards. Handy, handy.
Are you going to get that Exacta fence?forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Hi Ya... Nope on the xacta, its all yours... I need to get a note off to him and let him know. As far as two 110 legs splitting the receptical. I'm not sure if they even make a split receptacle or if its even legal to do that. You should probably open that question up to all members.
Cool idea with the bookcase.. My wood just keeps stacking up on top of things or against things, I have no idea whats in any of the piles any more. Perhaps this weekend will find me building something like you've done.Steve - in Northern California
Most receptacles can be split. There's usually a metal strap connecting the two hot (i.e., bronze-colored) screw terminals. Break that strap off and each outlet can be powered by its own hot.
Steve, take a look at the attached pic -- it's what I'd like to build down the road (From Shop Notes #55).
Anything I need to know about the Exacta? I sent Pat a note requesting info.
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Yep, thats exactly what I need to build this weekend. I think I have the wood to do it too. I'll let you know how it turns out. Thank you.
BarryO seems to have put the O.K. on splitting the outlet.
I didn't get any decisive info on the fence other than what is in the add. You might want to ask for a picture.Steve - in Northern California
Hi Steve -- I'm so far past jealousy, it's pathetic. Whine, whine, I just want my tablesaw to work! I keep having to go back to my little bench-top saw.
OK, now -- I like your idea of starting without the belt -- I'll try it.
I went out after work tonight and picked up a 20-amp receptacle/outlet, and a 20-amp plug, just to eliminate those as factors. If they don't fix it, I'll replace the circuit breaker. (I got the saw with a 15A plug, but the original owner ran it at 230V).
Steve, plz tell me: I asked this question earlier, but no one took the bait. Why does Jet put a 14ga cord on a motor that is pre-wired to draw 19 amps (at 115V)? It doesn't appear that this arrangement has caused you any trouble whatsoever, but it goes totally against all the electrical info I've gotten here and in my hand-dandy wiring book.
You're a pal! Thanks.
Hello, this is my first post. We moved into a house several years ago, and I had a constant problem blowing a breaker when we had a couple things plugged in - nothing that should blow the breaker. I bought a new breaker, switched them, and no problems ever since. Sometimes those breakers trip too easily, either because of how it was made, or over time. It's an easy thing to check, and pretty cheap. Good luck.
--Bob
f_g, I just looked through the manual and all it says is that the motor is pre-wired for 115 and shows a picture of what the plug and socket should look like. The socket is a standard 15 amp socket. My motor shows starting amps at 18 and running amps at 9. Theoreticaly that should blow a 15 amp breaker during start but it doesn't. They also recommend 12 guage extenstion cords at 25' and less. That would make me think they really want it on a 20 amp circuit.
Doesn't make sense to me to have an 18 or 19 amp start and a 14 gauge power cord unless the stranded wire in the power cord can handle more than solid wire. That goes against what I've been taught but my learnings were from several years ago and I haven't kept up on them.
Well, I'm out the door, headed to Austin TX on a Consulting job. I'll be interested to hear out it all works out.
Steve - in Northern California
(Wouldn't want Steve to think we didn't miss him, so I'll put some "mail" in his message-box here)
Yes, Yes, Yes! It worked! (She says, knocking on wood).
I changed out the circuit breaker, and while I didn't have time to work with the saw, I started and stopped it about 9 times, and the circuit didn't trip. Just hope I didn't jinx it by gloating here at Knots. Thanks for the info about running vs. starting amps. That is useful in keeping track of power load as I add a dust collector.
Hope you had a productive trip to Austin, Steve. What's Austin like? I've only been to San Antonio, which was a pretty fun place.
forestgirl
f_g, Congratulations...... Austin.. don't know yet, I'm still in the air.. Working from my cell phone... Pretty cool but also pretty slow. I won't get to see much of anything on this trip, its strictly business. Just a quick turn around red eye trip. Thanks for thinking about me..... BTW, yesterdays flight was cancelled so I had to catch a 6:15am flight out of Oakland Ca this morning. Been up since around 2:00am. Now to get back in time for another job, I have to catch a red eye back to San Francisco and then limo it back to Santa Rosa. I should get home about 24 hours after I left.
Steve - in Northern California
Edited 4/5/2002 12:52:21 PM ET by Steve Schefer
Hi FG
Did you try turning off the breaker and looking to see if other electrical appliances turned off. Some breakers can have two or three outlets on one breaker.
john g
Hi John, I think we've confused you with our tangential discussions. I've fixed the tablesaw-tripping-the-breaker problem by replacing the breaker (after replacing plugs and receptacles first). We're off on a theoretical discussion now! Have a tendency to get carried away occasionally. :)
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
I am not an electrician; but I do know that your amperage should not exceed 8o% of the breakers capacity. That is to say that for a 20A breaker, the maximum motor size(amp draw) that is safe to run is 16A. The 20A will handle the surge at start up, but anything more than a sustained 16A draw is too much.........The horizontal section on the 20A plugs and receptacles prevents you from plugging in a 20A device into a 15A receptacle, but allows you to plug a 15A device into a 20A receptacle, which is perfectly safe..........The maximum "one way distances for a customary2% voltage drop"as per Richter and Schwan "WIRING SIMPLIFIED" Park Publishing, is as follows:15A/120v 14GA-30', 12GA-45', 10GA-70'; 20A/120V 14GA-20'(TW wire may not be used), 12GA-35', 10GA-55'............15A/220V 14GA-60', 12GA-95', 10GA-150'...........20A/220V....14GA-45'(TW wire may not be used), 12GA-70', 10 GA-115'..............With all this said; sounds like you need a 30Amp/120V circut with 10GA wire, or a 15Amp/220V circut with at least 14GA wire(this doesn't however take in to account your extension cord, which should probably be 10GA).........Sorry...I hope I'm not confusing you.............It just sounds like your circuts are probably wired too small........Hope this helps.
Hophornbeam
Hi Hophornbeam, Thanks! No, not confusing me at all, although I can't seem to get the point across that I'm not using an extension cord :-)
It's obviously going to be easiest to just get the 220V outlet moved over so it's accessible. I'm still intrigued, though, by the fact that Steve has no problem running his Jet on 110V outlet. I'm going to open up the outlet and make sure it's clean and tightly wired, just for safety's sake. Also am going to try and find the guage information on the wiring. I realized late last night that when the electrician put in the sub-panel, some of the wiring in the garage remained the same. It's possible that the wiring to the outlets is 14ga rather than 12ga. Relatively easy to change that over, as at this moment there are only 2 outlets in there!
Thanks again!
Wire guage and length plays a big role in what you can and can't run on a circut. You can never go wrong by going to the next size (larger) wire. It is possible for a circut to work and yet exceed recomended safety limits. I wouldn't chance it.
Good Luck!
Hophornbeam
Edited 4/3/2002 1:29:55 PM ET by HOPHORNBEAM
Hello again FG! Did a search on the "110 to 220" question, read the thread...twice...and am about as confused as I can be. You seemed to have had a pretty good grasp of it. Soooooo......
Would you explain it to me in dunderhead terms?
I have a craftsman TS with a "3 peak HP" motor. A friend who seems to be knowledgable on electrical work, but not an electrician by license, says it would be fairly easy to run a 220 line into my garage shop and do a "simple" conversion to my saw resulting in more power to the saw and more torque (same thing?). As it stands, when I turn on the saw, I get the "death row brown out" for a few seconds before the saw goes to full speed.
Is doing this a good idea? I want to have more 110 plugs put in anyway so I may as well go to a dedicated 220 line for the TS while I'm at it Right?
Don't mean to put you on the spot. I know your not an electrician. Any advice or leads on information would be greatly appreciated.
Hope your well, Brian
Hi Brian, I know what you mean about the confusion factor with 220V vs. 110V (or 230V vs. 115V). I started my reading on that issue over a year ago.
Here's my humble take on it: All the scientific and engineering arguments aside, it comes down to how much demand I'm putting on my electrical in the shop. My saw does just fine on 115V, but it does dim the lights a bit on start-up. It's apparent that the total amperage available isn't giving me a big cushion for running more than one tool at a time, and I need to keep a pretty short distance between the motor and the outlet.
So, when the time comes I can get a dust collector, I'm going to finish out that 220V circuit that's available from the panel. By doing that, I'm freeing up amperage for other tools, lights, whatever. For me, it doesn't have anything to do with whether any given motor runs better, or more efficiently, or cooler or any of those things. It's about having more amperage available. Also, I think it will give me more flexibility as to the length of cord I can use without ill effects.
If my saw was giving the type of brown-out you're describing, I'd get it done sooner rather than later! Have fun. PS: No dunderheads here guy, we're smart!!!
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Edited 4/3/2003 12:25:55 PM ET by forestgirl
It also matters how you have things wired. My shop has a 240V subpanel. The lights and dust collector/air filter go on circuits that are on one pole. The 120V wall outlets are on circuits on the other pole. Tools at start-up don't affect the lights with this arrangement. The 240V tablesaw draws equally from both poles. Will soon know it if it affects the lights, but with 60A available, I suspect not.
Similarly, in the house we did a dedicated 15A circuit near a window in each BR for an AC unit. This way the AC cycling won't cause a brownout of the lights since they are on separate circuits.
Again, for the record, wiring for 220 shouldn't give you more power unless your original wiring was undersized for the task. 20A x 120V gives the same result as 10A x240V. Wiring for 220 halves the current flowing through the wires, thus decreasing losses due to resistance in the wire.
Excellant! Thanks! Guess my spaghetti factory extension cord approach doesn't get it. Will let you know how it turns out in a few weeks. Thanks again, B.
OOhhh, be careful with that extension cord stuff. I've killed a couple of small electrical toys by using undersized and very long cords. Motors get real grumpy about being starved. How long's the cord??forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
OK, now I'm really going to be embarrassed. My table saw is on a total of three cords...about 20 feet from recepticle. Gotta do something about this I know.Very soon. B.
Yesterday, Brian, yesterday! Yikes. Get thee a 25-foot 12 gauge, or at the worst 14. You'll find other uses for it after the 220 gets in. Gives you a great excuse to go to the toy store, if you get my drift.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
first thing Monday...I'll shoot for a 10 Ga..if not available i'll go to a 12.
**I have a craftsman TS with a "3 peak HP" motor. A friend who seems to be knowledgable on electrical work, but not an electrician by license, says it would be fairly easy to run a 220 line into my garage shop and do a "simple" conversion to my saw resulting in more power to the saw and more torque (same thing?).
From the comments I've read from others, Craftsman is one of the worst at overrating their motors (makes good advertising). I may have missed something in this thread, and since I don't know what kind of TS motor you have, my comments may be totally off the wall, but I was under the impression the "peak hp" rating was usually given to tools with universal motors, since on a universal motor, hp increases with load up to a theoretical point just before the motor stalls and the windings burn up. Most such motors have a more realistic rating of 1.5HP.
I think you've got to have an induction motor on the saw before thinking about rewiring. If you have a universal motor saw, you could run it on 220V and get twice the rpm . . . for a few seconds, just before everything melted.
". . .and only the stump or fishy part of him remained."
Green Gables: A Contemplative Companion to Fujino Township
Edited 4/6/2003 9:53:47 PM ET by Norm in Fujino
Thanks Norm, will check before letting this guy anywhere near my saw. Brian
Boy, Norm spotted that discrepancy while I was just assuming you had a belt-driven motor. Oooops! Yep, if your saw is one of those direct-drive models this whole conversation's pretty moot (except for the part about a good extension cord). Nothing like overlooking the obvious. Sorry.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
My craftsman saw says max developed hp. Check your manual if you have one. It will tell you if you can wire your saw for 220v & how to do it.
Cool. thx!
Forest Girl,
Jet technical services recommends only using a 10 gauge cord for replacements or extension (cords). The chief electrical contractor that I use in my shop, recommended against exchanging a lower amp breaker for a higher one (e.g. 20 amp to 30 amp), especially if the lower amp breaker is what's recommended. The reason being, is that the breaker is meant to "pop" at a certain electrical level. If a higher amp breaker is used, it means the machine plugged into it will have to be under a greater amount of detrimental strain for a longer period of time before it throws the switch. Even though it may be inconvenient, it is probably best to leave the lower amp breaker, and have an electrician check the system to determine why you're getting a blown switch (breaker) every three to four machine usages.
Dan Kornfeld, Owner/President - Odyssey Wood Design, Inc.
I don't understand how they can recommend 10 gauge when they put 14 gauge on the machines originally! I could understand it if it were a long, long extension cord, but 10 gauge on a, say 10-foot, cord seems serious overkill. I think they heaviest Romex in my shop is 12 gauge.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
They recommend 10 guage to keep themselves out of trouble. Far easier to recommend 10 guage for all extension cords tha 14 ga for up to ten feet, 12 ga for 10-25 ft etc... Tom
Point made -- they wouldn't get me to swallow that recommendation no questions asked fer sure. forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
They recommend 10 guage to keep themselves out of trouble.
Well not exactly. They recommend it because of the problems caused by undersizing wire. The way I look at it in a very simplistic form is that if a 14 gauge wire is designed to handle 15 amps it will do so for a short distance. Go to a larger diameter wire, say 10 gauge and the wire will carry the same 15 amps more efficently. This to me is the reserve that makes the tool recieve the proper amount of power and amperage over distance. I have seen all the tables that define wire size vs. ampacity and I am a firm believer that they are accurate. I personally would not even attempt to run a power hungry source on undersized wire.
The thing most have a hard time understanding is that the cord coming out of the tool can be 14 gauge or whatever the tool requires because it only has to run a short distance( to the motor)
What becomes a killer of wire sizing is to use a power cord the same diameter as that of the motor over a long distance, or using a smaller size diameter wire than the motor requires.
Undersizing a extension cord is the reason that cheap extension cords used around the house for lamps and such caused homes to burn down.
The wire was trying to keep up with the power requiements of the light or appliance and generated enough heat to start a fire.
Joe
"The wire was trying to keep up with the power requiements of the light or appliance and generated enough heat to start a fire."
That is exactly why I said they recommend the larger size wire to keep themselves out of trouble. Far easier to recommend the larger size and eliminate the possibility of the end user misinterpreting the manual. Tom
That is a daily event in Baltimore in the summer. Someone has their power shut off, so they run the AC unit with an extension cord or two from next door, and since those cords are ugly, they shove it under a rug.
I figured I could add a little emphircal evidence to this thread. First, about 3 years ago I bought a Made in China 14 speed drill press that came with a 2HP 110v/220v motor. It came wired 110v. It would always trip the breaker (10 gauge wire, 25 amp breaker, 10' run) when trying to start it using the 3 highest speeds. I rewired it to 220v and the problem went away. Also, I have noticed that in a lot of machines used in production environments that have relatively low HP motors use very high voltages (must be a reason). I have a 1HP spindle sander that came out of a pattern shop that has a 208v/220v/440v 3 phase motor. Draws 2 amps when wired for 440.
Jon
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