220V dryer sparked on startup (3 wire) What to test?
The wife said the dryer was sparking "in the back".
I moved things around, but didn't see anything so I tell the wife not to worry. A week later, I turn on the 220v 3-wire dryer, and a single bright white spark snaps in the back, between the dryer and the 4-foot 6-inch diameter aluminum corrugated lint pipe connect to the outside vent. Huh? Could it be static electricity? Could it be the dryer frame is hot? What do I test? The only connection to the wall is the three-pronged 220v dryer cord, which looks perfectly fine when I remove it from the wall outlet. There is no specific "ground" wire from the dryer to anything (should I have put a ground wire in to the 120 volt outlet nearby?). What would you test? If you need pictures, just ask. |
220V dryer sparked on startup (3 wire) What to test?
On 11/14/2013 3:44 PM, Danny D'Amico wrote:
The wife said the dryer was sparking "in the back". I moved things around, but didn't see anything so I tell the wife not to worry. A week later, I turn on the 220v 3-wire dryer, and a single bright white spark snaps in the back, between the dryer and the 4-foot 6-inch diameter aluminum corrugated lint pipe connect to the outside vent. Huh? Could it be static electricity? Could it be the dryer frame is hot? What do I test? The only connection to the wall is the three-pronged 220v dryer cord, which looks perfectly fine when I remove it from the wall outlet. There is no specific "ground" wire from the dryer to anything (should I have put a ground wire in to the 120 volt outlet nearby?). What would you test? If you need pictures, just ask. My gut sense, is that something is loose inside the dryer. Something (sounds like) is touching the case of the dryer, and charging it. I'd pull the plug, check for continuity between power and ground prongs of the plug. I'd also open up the case, and look for bare, burnt, or loose wires. Do you have any friends with electrical skills? -- .. Christopher A. Young Learn about Jesus www.lds.org .. |
220V dryer sparked on startup (3 wire) What to test?
"Danny D'Amico" wrote in message ... The wife said the dryer was sparking "in the back". I moved things around, but didn't see anything so I tell the wife not to worry. A week later, I turn on the 220v 3-wire dryer, and a single bright white spark snaps in the back, between the dryer and the 4-foot 6-inch diameter aluminum corrugated lint pipe connect to the outside vent. Huh? Could it be static electricity? Could it be the dryer frame is hot? What do I test? The only connection to the wall is the three-pronged 220v dryer cord, which looks perfectly fine when I remove it from the wall outlet. There is no specific "ground" wire from the dryer to anything (should I have put a ground wire in to the 120 volt outlet nearby?). What would you test? If you need pictures, just ask. It could be static electricity. Is the 4 foot long vent pipe seperated from the dryer by some material that does not conduct electricity ? If so you may want to connect a wire between the pipe and dryer. It does not have to be very large as almost no curent is going through it, just high voltage. You may also want to look at the dryer where the power wire is. As this is only a 3 wire cord make sure there is a strapgoing from the neutral wire to the frame of the dryer. This should be factory installed so it can be used for 3 wires or bent out of the way if a 4 wire cable is used. While it may not trip a breaker, I would think it might if there was an intermittant short in the power wiring. |
220V dryer sparked on startup (3 wire) What to test?
Ralph Mowery wrote:
"Danny D'Amico" wrote in message ... The wife said the dryer was sparking "in the back". I moved things around, but didn't see anything so I tell the wife not to worry. A week later, I turn on the 220v 3-wire dryer, and a single bright white spark snaps in the back, between the dryer and the 4-foot 6-inch diameter aluminum corrugated lint pipe connect to the outside vent. Huh? Could it be static electricity? Could it be the dryer frame is hot? What do I test? The only connection to the wall is the three-pronged 220v dryer cord, which looks perfectly fine when I remove it from the wall outlet. There is no specific "ground" wire from the dryer to anything (should I have put a ground wire in to the 120 volt outlet nearby?). What would you test? If you need pictures, just ask. It could be static electricity. Is the 4 foot long vent pipe seperated from the dryer by some material that does not conduct electricity ? If so you may want to connect a wire between the pipe and dryer. It does not have to be very large as almost no curent is going through it, just high voltage. You may also want to look at the dryer where the power wire is. As this is only a 3 wire cord make sure there is a strapgoing from the neutral wire to the frame of the dryer. This should be factory installed so it can be used for 3 wires or bent out of the way if a 4 wire cable is used. While it may not trip a breaker, I would think it might if there was an intermittant short in the power wiring. Hi, What is your multi-meter doing? How about measuring things between vent pipe and dryer body for a starter? 220V can kill..... |
220V dryer sparked on startup (3 wire) What to test?
On Thu, 14 Nov 2013 15:55:24 -0500, Stormin Mormon wrote:
I'd pull the plug, check for continuity between power and ground prongs of the plug. I'd also open up the case, and look for bare, burnt, or loose wires. This is the 3-pronged 220 volt cord connected to this dryer: http://farm6.staticflickr.com/5495/1...a63d0028_o.gif I think, IIRC, two of the prongs are 120 volt hot wires, 120 degrees out of phase (that's the 220 volts); while the third, I think, is a neutral wire. So, I think, IIRC, the 120V circuitry in the dryer (e.g., the light bulb and the controls and perhaps even the motor) run off one of the hot wires and the neutral; while the heater runs off the full 220 volts from the two hot wires and the neutral. So, there is no ground that I know of, if I understood this correctly. That's why I asked if you guys ADD a ground wire in this situation? http://farm4.staticflickr.com/3753/1...473a60a8_o.gif |
220V dryer sparked on startup (3 wire) What to test?
On Thu, 14 Nov 2013 16:47:47 -0500, Ralph Mowery wrote:
It could be static electricity. Is the 4 foot long vent pipe seperated from the dryer by some material that does not conduct electricity ? I'm not sure HOW static electricity could build up, but, that's the only thing, at the moment, that makes sense to me. Here's a picture of what the vent hose looks like when it's all in place: http://farm4.staticflickr.com/3815/1...c2fe362f_o.gif Here's a front view: http://farm4.staticflickr.com/3833/1...2c472367_o.gif |
220V dryer sparked on startup (3 wire) What to test?
On Thu, 14 Nov 2013 16:47:47 -0500, Ralph Mowery wrote:
You may also want to look at the dryer where the power wire is. As this is only a 3 wire cord make sure there is a strap going from the neutral wire to the frame of the dryer. This should be factory installed so it can be used for 3 wires or bent out of the way if a 4 wire cable is used. Hmmm... There is no *external* 'strap" going to the steel frame of the dryer. Are you saying there should be an *internal* strap that I can look for? http://farm4.staticflickr.com/3812/1...f128caf4_o.gif |
220V dryer sparked on startup (3 wire) What to test?
On 11/14/2013 7:25 PM, Danny D'Amico wrote:
.... So, there is no ground that I know of, if I understood this correctly. .... No, you misunderstood (or the reference you looked at was wrong; I didn't check it) -- the third wire is the ground but NEC until relatively recently allowed the ground to also be the neutral in specific instances, the household dryer likely the most prevalent followed closely by electric range. The "blinding flash" _may_ have been one of the two heater coils failing -- does the dryer still reach full temp and otherwise function properly as far as you can tell? If it's now taking a lot longer for things to dry, likely you did lose an element. If, as somebody else noted, it didn't trip the breaker the likelihood of a short other than the element is minute. In 60 yrs in a dry climate I've never seen a static electricity flash from a dryer vent or even got a shock so don't say it's not possible but surely sounds far-fetched hypothesis to me. OTOH, when wife sewed a lot or when were many cloth diapers so that straight or safety pins accidentally getting in the dryer caused fair number of element shorts when one would finally manage to get thru the vent holes in the rear of the drum and land across a heater coil. Or, they do eventually fail on their own... -- |
220V dryer sparked on startup (3 wire) What to test?
"Danny D'Amico" wrote in message ... On Thu, 14 Nov 2013 16:47:47 -0500, Ralph Mowery wrote: You may also want to look at the dryer where the power wire is. As this is only a 3 wire cord make sure there is a strap going from the neutral wire to the frame of the dryer. This should be factory installed so it can be used for 3 wires or bent out of the way if a 4 wire cable is used. Hmmm... There is no *external* 'strap" going to the steel frame of the dryer. Are you saying there should be an *internal* strap that I can look for? http://farm4.staticflickr.com/3812/1...f128caf4_o.gif This looks like a 3 wire power cord. You need to unplug the dryer and open up the back where the wire goes in. Look and there will be 3 terminals the power wire hooks to. It will probably be the middle wire that is the neutral and there should be a strap going from there to the frame of the dryer. While the dryer is open look around for any black or burnt areas near wires or the internal electrical parts. |
220V dryer sparked on startup (3 wire) What to test?
On Thu, 14 Nov 2013 19:39:38 -0600, dpb wrote:
the third wire is the ground but NEC until relatively recently allowed the ground to also be the neutral You seem to understand this better than I do. The way *I* understand a "ground" is that a ground wire carries no current (unless there is a problem). The "neutral" wire, on the other hand, *always* carries current. That's a pretty big difference (as I understand it anyway). More specifically, the way I understand a ground wire, is that it goes from the receptacle in the wall to the main breaker panel, where it literally is driven directly into the ground (usually by some kind of bar). In contrast, the neutral wire, as I understand it, goes to the same breaker panel, but then it goes from there to the power pole, and then from that pole it may travel hundreds of feet to a few more power poles, but eventually, it too is driven straight into the ground. The difference, as I understand it, is that the ground never carries current (unless there is a fault), while the neutral is always carrying current (and therefore it might have a potential on it). Given that they're not at all the same thing, I then have trouble understanding the statement that the ground is "also" a neutral. Again, you seem to understand better than I do, but, the way I described it above, a ground and a neutral are totally different things. So, I don't understand how a ground can 'also' be a neutral. |
220V dryer sparked on startup (3 wire) What to test?
On Thu, 14 Nov 2013 19:39:38 -0600, dpb wrote:
The "blinding flash" _may_ have been one of the two heater coils failing -- does the dryer still reach full temp and otherwise function properly as far as you can tell? If it's now taking a lot longer for things to dry, likely you did lose an element. As far as I know, the dryer works just fine. My wife said it was making static sounds in the back, when she turned it on about a week ago, which I had dismissed until I saw the bright spark at the aluminum vent hose when I turned it on. The spark happened quickly, so, I'm not exactly sure *where* it was, but, it was *OUTSIDE* the dryer. The white spark *appeared* to be between the dryer frame and the aluminum vent hose, as shown in this picture in a RED mark: http://farm6.staticflickr.com/5494/1...9cd016bd_o.png |
220V dryer sparked on startup (3 wire) What to test?
On Thu, 14 Nov 2013 19:39:38 -0600, dpb wrote:
If, as somebody else noted, it didn't trip the breaker the likelihood of a short other than the element is minute. In 60 yrs in a dry climate I've never seen a static electricity flash from a dryer vent or even got a shock so don't say it's not possible but surely sounds far-fetched hypothesis to me. This is good to know, since the static electricity idea was the only one I could come up with that was benign. I would agree that static electricity isn't likely, so, let's forget about that. But, if it's not something benign, then I need to figure out WHAT is making that spark, and why. The whole fact that there is no explicit ground is part of what confuses me. I'll check to see if the body of the dryer is hot with respect to ground. |
220V dryer sparked on startup (3 wire) What to test?
On Thu, 14 Nov 2013 16:47:47 -0500, Ralph Mowery wrote:
While it may not trip a breaker, I would think it might if there was an intermittant short in the power wiring. Just to confirm, there is a breaker in the laundry room and it has not tripped. So, whatever it is, it isn't pulling enough current for a long enough time to overheat the breaker switch. |
220V dryer sparked on startup (3 wire) What to test?
"Danny D'Amico" wrote in message ... On Thu, 14 Nov 2013 19:39:38 -0600, dpb wrote: the third wire is the ground but NEC until relatively recently allowed the ground to also be the neutral You seem to understand this better than I do. The way *I* understand a "ground" is that a ground wire carries no current (unless there is a problem). The "neutral" wire, on the other hand, *always* carries current. That's a pretty big difference (as I understand it anyway). More specifically, the way I understand a ground wire, is that it goes from the receptacle in the wall to the main breaker panel, where it literally is driven directly into the ground (usually by some kind of bar). In contrast, the neutral wire, as I understand it, goes to the same breaker panel, but then it goes from there to the power pole, and then from that pole it may travel hundreds of feet to a few more power poles, but eventually, it too is driven straight into the ground. The difference, as I understand it, is that the ground never carries current (unless there is a fault), while the neutral is always carrying current (and therefore it might have a potential on it). Given that they're not at all the same thing, I then have trouble understanding the statement that the ground is "also" a neutral. Again, you seem to understand better than I do, but, the way I described it above, a ground and a neutral are totally different things. So, I don't understand how a ground can 'also' be a neutral. The power comes into your house by 3 wires. At the pole is a transformer that has a wire on each end of a coil and one from the center. If you only used 240 volt devices there would be no need for the neutral wire. If the power usage on each side of the 120 volt lines were exectally the same there would not be any need for the neutral going to the pole. As the sides are not exectally ballanced and often not ballanced very well at all, the neutral carries the unballanced current. In the house the 120 volt circuits use one of the hot wires and the neutral for the return. At your breaker box the neutral is bolted to the frame of the box and it also goes to the recepticls and other parts of the house. The ground wire goes to a rod outside the house that is driven into the ground. It is bolted to the frame of the breaker box. It then also goes whever the power wires goes to such as the recepticals. In effect the neutral and ground wire are the same wire, but perform differant functions. Often the neutral or ground wire may be a differant size than the two hot 240 volt wires. If the neutral and ground wires are the same size, there is no electrical reason that you could not use either of them for the ground or neutral. YOu do not want to do this as it can create great confusion to the people doing the wiring. That is one reason the neutral is insulated and white and the ground is either bare or green. The two hot wires may be red and black or maybe just two black wires as it does not usually mater which wire is hooked to which side of the 240 volt device. YOu are correct, there should not be any current on the ground wire unless there is a problem. If one of the hot wires shorts to the frame of the dryer and there is no ground or neutral (on a 3 wire plug) connected to the frame, it becomes 120 volts to ground and if you or anything conductive gets between the frame and the real ground or another device that has its frame grounded, there will be current flowing and could shock or kill. If in the 3 wire circuit the neutral becomes disconnected down line of the dryer, the frame of the dryer will become hot with 120 volts minus a small ammount. That small ammount could be the timmer and light bulb in the dryer that is still connected to one side of the 240 volt line. That is the reason for using the 4th wire that is only connected to the frame of the dryer in later years. |
220V dryer sparked on startup (3 wire) What to test?
On 11/14/2013 8:25 PM, Danny D'Amico wrote:
On Thu, 14 Nov 2013 15:55:24 -0500, Stormin Mormon wrote: I'd pull the plug, check for continuity between power and ground prongs of the plug. I'd also open up the case, and look for bare, burnt, or loose wires. This is the 3-pronged 220 volt cord connected to this dryer: http://farm6.staticflickr.com/5495/1...a63d0028_o.gif I think, IIRC, two of the prongs are 120 volt hot wires, 120 degrees out of phase (that's the 220 volts); while the third, I think, is a neutral wire. So, I think, IIRC, the 120V circuitry in the dryer (e.g., the light bulb and the controls and perhaps even the motor) run off one of the hot wires and the neutral; while the heater runs off the full 220 volts from the two hot wires and the neutral. So, there is no ground that I know of, if I understood this correctly. That's why I asked if you guys ADD a ground wire in this situation? http://farm4.staticflickr.com/3753/1...473a60a8_o.gif You're out of your field of training, here, my friend. I'd suggest you find someone you can trust, who knows some about electricity. Two hots, and a ground. No neutral wire. -- .. Christopher A. Young Learn about Jesus www.lds.org .. |
220V dryer sparked on startup (3 wire) What to test?
On 11/14/2013 8:29 PM, Danny D'Amico wrote:
On Thu, 14 Nov 2013 16:47:47 -0500, Ralph Mowery wrote: You may also want to look at the dryer where the power wire is. As this is only a 3 wire cord make sure there is a strap going from the neutral wire to the frame of the dryer. This should be factory installed so it can be used for 3 wires or bent out of the way if a 4 wire cable is used. Hmmm... There is no *external* 'strap" going to the steel frame of the dryer. Are you saying there should be an *internal* strap that I can look for? http://farm4.staticflickr.com/3812/1...f128caf4_o.gif Please be careful listening to this person. Three wire dryer connection has two hots and a ground. No neutral. And, you'd never deliberately connect a neutral to the frame or case. -- .. Christopher A. Young Learn about Jesus www.lds.org .. |
220V dryer sparked on startup (3 wire) What to test?
On 11/14/2013 8:39 PM, Ralph Mowery wrote:
This looks like a 3 wire power cord. You need to unplug the dryer and open up the back where the wire goes in. Look and there will be 3 terminals the power wire hooks to. It will probably be the middle wire that is the neutral and there should be a strap going from there to the frame of the dryer. While the dryer is open look around for any black or burnt areas near wires or the internal electrical parts. Three wire cord doesn't have a neutral. Two hots and a ground. -- .. Christopher A. Young Learn about Jesus www.lds.org .. |
220V dryer sparked on startup (3 wire) What to test?
On 11/14/2013 8:55 PM, Danny D'Amico wrote:
So, I don't understand how a ground can 'also' be a neutral. Both go to the Earth. Small loads like a timer, can flow a small enough current, that it doesn't noticeably raise the electrical potential of the ground line. -- .. Christopher A. Young Learn about Jesus www.lds.org .. |
220V dryer sparked on startup (3 wire) What to test?
"Tony Hwang" wrote in message ... Ralph Mowery wrote: "Danny D'Amico" wrote in message ... The wife said the dryer was sparking "in the back". I moved things around, but didn't see anything so I tell the wife not to worry. A week later, I turn on the 220v 3-wire dryer, and a single bright white spark snaps in the back, between the dryer and the 4-foot 6-inch diameter aluminum corrugated lint pipe connect to the outside vent. Huh? Could it be static electricity? Could it be the dryer frame is hot? What do I test? The only connection to the wall is the three-pronged 220v dryer cord, which looks perfectly fine when I remove it from the wall outlet. There is no specific "ground" wire from the dryer to anything (should I have put a ground wire in to the 120 volt outlet nearby?). What would you test? If you need pictures, just ask. It could be static electricity. Is the 4 foot long vent pipe seperated from the dryer by some material that does not conduct electricity ? If so you may want to connect a wire between the pipe and dryer. It does not have to be very large as almost no curent is going through it, just high voltage. You may also want to look at the dryer where the power wire is. As this is only a 3 wire cord make sure there is a strapgoing from the neutral wire to the frame of the dryer. This should be factory installed so it can be used for 3 wires or bent out of the way if a 4 wire cable is used. While it may not trip a breaker, I would think it might if there was an intermittant short in the power wiring. Hi, What is your multi-meter doing? How about measuring things between vent pipe and dryer body for a starter? 220V can kill..... Tony,,, You can only get the one leg of voltage to ground on a 220 volt system on a dryer. However that also is dangerous. The OP may have a sagging heater coil that is touching the case. If he is not handy on this stuff, time to get an appliance repairman to check and repair it. WW |
220V dryer sparked on startup (3 wire) What to test?
"Stormin Mormon" wrote in message ... Please be careful listening to this person. Three wire dryer connection has two hots and a ground. No neutral. And, you'd never deliberately connect a neutral to the frame or case. Hate to inform you, but in a 3 wire dryer socket there are 2 hots and a neutral. There is no ground. Go here and learn. http://www.how-to-wire-it.com/wire-a-dryer-cord.html Also notice the picture where the frame of the dryer is attached to the neutral wire. |
220V dryer sparked on startup (3 wire) What to test?
"Stormin Mormon" wrote in message ... On 11/14/2013 8:39 PM, Ralph Mowery wrote: This looks like a 3 wire power cord. You need to unplug the dryer and open up the back where the wire goes in. Look and there will be 3 terminals the power wire hooks to. It will probably be the middle wire that is the neutral and there should be a strap going from there to the frame of the dryer. While the dryer is open look around for any black or burnt areas near wires or the internal electrical parts. Three wire cord doesn't have a neutral. Two hots and a ground. -- . Christopher A. Young Learn about Jesus www.lds.org . Wrong! Two hots and a grounded conductor (neutral/white). These types of plugs are often referred as a 120/240. Meaning that it provides both voltages to the device. The new 4-wire plugs do the same thing, but have a dedicated grounding conductor for fault purposes. As per code, a grounding conductor shall "never" carry any current unless a fault is present; and the only purpose for carrying this current is to trip the breaker. The other purpose of a grounding conductor is to equalize the potential of attached devices to ground, thereby reducing, but not eliminating, the risk of shock. (it is possible that the service is 110/220) |
220V dryer sparked on startup (3 wire) What to test?
"Danny D'Amico" wrote in message ... On Thu, 14 Nov 2013 19:39:38 -0600, dpb wrote: the third wire is the ground but NEC until relatively recently allowed the ground to also be the neutral You seem to understand this better than I do. The way *I* understand a "ground" is that a ground wire carries no current (unless there is a problem). The "neutral" wire, on the other hand, *always* carries current. You are correct. In old installations range and dryer outlets only had three wires, and it was allowed to use the "neutral" as a ground fault path. |
220V dryer sparked on startup (3 wire) What to test?
On 11/14/2013 11:00 PM, Ralph Mowery wrote:
"Stormin Mormon" wrote in message ... Please be careful listening to this person. Three wire dryer connection has two hots and a ground. No neutral. And, you'd never deliberately connect a neutral to the frame or case. Hate to inform you, but in a 3 wire dryer socket there are 2 hots and a neutral. There is no ground. Go here and learn. http://www.how-to-wire-it.com/wire-a-dryer-cord.html Also notice the picture where the frame of the dryer is attached to the neutral wire. Well, golly gee! http://www.ezdiyelectricity.com/?p=221 http://electrical.about.com/od/appli...ercordss_4.htm It sure seemed counter intuitive that the third prong would be neutral, and the device is ungrounded. But, I found a couple web sites that say it is. And says that it bonds the neutral to the frame. Go figure. Well, thanks for showing me some thing new. I find myself with egg on my face. http://fc03.deviantart.net/fs71/i/20...ss-d536n7e.jpg Good thing I've been recently instructed how to apologize. http://youqueen.com/wp-content/uploa...-Apologize.jpg -- .. Christopher A. Young Learn about Jesus www.lds.org .. |
220V dryer sparked on startup (3 wire) What to test?
On 11-14-2013, 20:27, Danny D'Amico wrote:
On Thu, 14 Nov 2013 16:47:47 -0500, Ralph Mowery wrote: It could be static electricity. Is the 4 foot long vent pipe seperated from the dryer by some material that does not conduct electricity ? I'm not sure HOW static electricity could build up, but, that's the only thing, at the moment, that makes sense to me. If it only happens when you turn it on, it wouldn't be static build up. That would have dissipated while it was off. I'm wondering about some kind of misalignment or wearing out in a two-pole switch. If one side of the 240 is energized ten milliseconds before the other, AND that side is shorted to the shell, AND the shell is not grounded but the vent hose _is_, then this could happen. And that would be dangerous, obviously. Call a pro. Happy Halloween. -- Wes Groleau €śBrigham Young agrees to confine himself to one woman, if every member of Congress will do the same.€ť €” Weekly Republican, 1869 |
220V dryer sparked on startup (3 wire) What to test?
"Stormin Mormon" wrote in message ... It sure seemed counter intuitive that the third prong would be neutral, and the device is ungrounded. But, I found a couple web sites that say it is. And says that it bonds the neutral to the frame. Go figure. For common house circits there is no real electrical differance in the neutral and ground wires. They both start at the same point in the breaker panel and run parallel with each other to the socket or device that they are connected to. .. Mechanically there is often a differance. The ground will either be bare or green and the neutral will be white by the electrical code. They may even be differant sizes. When used in the 240 volt circuits the 4 th wire ground is just a redundant wire that is connected to the frame of the device . This is an added safety precaution incase for some reason the neutral wire would become disconnected if only a 3 wire circuit was used. |
220V dryer sparked on startup (3 wire) What to test?
On Thu, 14 Nov 2013 21:40:25 -0500, Stormin Mormon wrote:
Two hots, and a ground. No neutral wire. I may well be out of my league, but, I've wired 220 in the past, and, well, *I* used two black and one white (i.e., two hots and a neutral), and it worked, for me. My problem at that time was that the wiring was in an old house with screw-in fuses, so, that arrangement above would tend to blow one fuse but not the other, which wasn't really a good idea. I could tell a fuse had blown 'cuz the motor would hum instead of move for the compressor. But, when I replaced the fuse, it would work again. Dumb. Yes. I agree. Darwin award even? Perhaps. But, clearly, *my* 220 in that case was two hots and a neutral. I supposed had I two hots and a ground wire tied to the cold water pipe, it would have worked as well. And, I must note, that I've *followed* the neutral wire, in the olden days, when wires were above ground, from the house, to the pole, to the next pole, to the next (as far as I could tell anyway), until it went straight into the ground. Of course, I really didn't follow the wire directly, but, I surmised the neutral went into the ground at every third pole. At least that's what I remember surmising way back when ... So, *both* a ground and a neutral go into the ground. The only difference, as I see it, is that the neutral goes into the ground hundreds of feet away, and it carries current; while the ground goes into the ground at the edge of the house, and, it's not carrying current (unless there is a fault). So, given all that, I think we're talking semantics here. I have two hots and this "thing" which goes into the ground a few hundred yards from the house. Apparently this "thing" is acting both as a ground, and as a neutral. I'm going to check that this "thing" is actually *connected* to the steel case of the dryer and report back! Thanks! |
220V dryer sparked on startup (3 wire) What to test?
On Fri, 15 Nov 2013 22:14:25 +0000, Danny D. wrote:
I have two hots and this "thing" which goes into the ground a few hundred yards from the house. By the way, the reason (I think) I know that this 'thing' is a neutral (and not a ground) is that it *must* be carrying current. If the two hots were out of phase by 180 degrees, then we wouldn't need this third 'thing'. But, three wire distribution along the poles is such that the hot wires are only 120 degrees out of phase (IIRC). So, if I'm correct, my two hots are 120 degrees out of phase, which means current *must* be going somewhere. That somewhere is this third 'thing'. Since this third 'thing' is designed to carry current, it's clearly not a ground (since a ground isn't designed to carry current normally). Now, again, the fact that this third 'thing' goes into the ground makes it 'look' like a ground (to some); but it *must* be carrying current; so, semantically, I wouldn't call it a ground. Still - I must profess ... this is only how *I* understand the situation; and I may well be wrong (although I think it's this way). So, I will try to explain what you guys are trying to tell me in the next post (this is too long already). |
220V dryer sparked on startup (3 wire) What to test?
On Fri, 15 Nov 2013 22:21:18 +0000, Danny D. wrote:
So, I will try to explain what you guys are trying to tell me in the next post (this is too long already). I think you guys are trying to tell me that this third 'thing' goes from the wall to the dryer innards. At the same time, it goes to the dryer steel frame! So, if one of the hot wires were to touch the steel frame, it would go into this third 'thing' and it would go back to the wall. And, from the wall, it would go to the breaker box; and from the breaker box to the power pole; and from the power pole to another, and finally, a pole or three away, it would go into the ground. Back at the dryer, that would mean that the steel case of the dryer is attached to the ground by a long wire of a few hundred feet or more. So, the steel case *could* have a potential on it! (which would be the difference in voltage between the hot wire and the ground a few hundred feet away). |
220V dryer sparked on startup (3 wire) What to test?
On Fri, 15 Nov 2013 01:25:56 +0000 (UTC), Danny D'Amico
wrote: On Thu, 14 Nov 2013 15:55:24 -0500, Stormin Mormon wrote: I'd pull the plug, check for continuity between power and ground prongs of the plug. I'd also open up the case, and look for bare, burnt, or loose wires. This is the 3-pronged 220 volt cord connected to this dryer: http://farm6.staticflickr.com/5495/1...a63d0028_o.gif I think, IIRC, two of the prongs are 120 volt hot wires, 120 degrees out of phase (that's the 220 volts); while the third, I think, is a neutral wire. 180 degrees, but technically, no. It's opposite sign, not 180 degrees out of phase. ...and it should be 240V (twice 120V). So, I think, IIRC, the 120V circuitry in the dryer (e.g., the light bulb and the controls and perhaps even the motor) run off one of the hot wires and the neutral; while the heater runs off the full 220 volts from the two hot wires and the neutral. The timer usually runs off 120V. So, there is no ground that I know of, if I understood this correctly. That's why I asked if you guys ADD a ground wire in this situation? http://farm4.staticflickr.com/3753/1...473a60a8_o.gif The ground is a must, for safety. At one time, it was allowed to run the timer current though ground. A neutral conductor is now required for that current. |
220V dryer sparked on startup (3 wire) What to test?
On Thu, 14 Nov 2013 15:21:16 -0700, Tony Hwang wrote:
What is your multi-meter doing? How about measuring things between vent pipe and dryer body for a starter? 220V can kill..... Nothing is hot. At least now. |
220V dryer sparked on startup (3 wire) What to test?
On Thu, 14 Nov 2013 19:50:13 -0700, WW wrote:
The OP may have a sagging heater coil that is touching the case. That's interesting. I never saw a heater coil, let alone a sagging heater coil. Googling for images, I see these: http://www.partsdr.com/Parts/279838-...er=Forum279838 http://www.rcappliancepartsimages.co...7/00021876.jpg I'll have to look deeper... |
220V dryer sparked on startup (3 wire) What to test?
On Thu, 14 Nov 2013 20:39:41 -0500, Ralph Mowery wrote:
While the dryer is open look around for any black or burnt areas near wires or the internal electrical parts. Does this look ok from where you sit? http://farm6.staticflickr.com/5474/1...cb94ac7e_o.gif |
220V dryer sparked on startup (3 wire) What to test?
On Thu, 14 Nov 2013 21:42:54 -0500, Stormin Mormon wrote:
Three wire cord doesn't have a neutral. Two hots and a ground. There is a bolt for an external ground he http://farm6.staticflickr.com/5474/1...cb94ac7e_o.gif |
220V dryer sparked on startup (3 wire) What to test?
On Thu, 14 Nov 2013 23:00:26 -0500, Ralph Mowery wrote:
Go here and learn. http://www.how-to-wire-it.com/wire-a-dryer-cord.html Thank you so much for finding that reference for us! I was getting confused, by the conflicting information. This is what my wires look like at the dryer: http://farm4.staticflickr.com/3670/1...5821a83c_o.gif I'll need to go back there and doublecheck that the white wire that is connected to the frame is also connected to that middle (white) wire (neutral?) which is surrounded by two black wires (hot). |
220V dryer sparked on startup (3 wire) What to test?
to the op
caution, this may be dangerous you have read that the 3 prong setup shares the ground and the neutral. so if this shared ground neutral should have a loose wire, this could cause the dryer frame to become energized. and perhaps the metal vent pipe is completing the circuit to ground. that may be why you hear and see sparks. i would not use this appliance again until this is fixed if you feel you can handle this, do what you suggested, run a heavy wire from the dryer frame to a nearby outlet ground. after you add a ground , this should make it relatively safe, but get someone to check it before you get shocked or start a fire. Mark |
220V dryer sparked on startup (3 wire) What to test?
"Danny D'Amico" wrote in message ... On Thu, 14 Nov 2013 23:00:26 -0500, Ralph Mowery wrote: Go here and learn. http://www.how-to-wire-it.com/wire-a-dryer-cord.html Thank you so much for finding that reference for us! I was getting confused, by the conflicting information. This is what my wires look like at the dryer: http://farm4.staticflickr.com/3670/1...5821a83c_o.gif I'll need to go back there and doublecheck that the white wire that is connected to the frame is also connected to that middle (white) wire (neutral?) which is surrounded by two black wires (hot). I don't see any provision for a strap from the dryer frame to the center neutral connection for that particular dryer. It would be good to know where that white wire that is under the ground screw comes from. I have not seen it, but can you give the make and model of the dryer so I can look for a wiring diagram for it ? If you have the book for it, it may have the diagram in it for a 4 and 3 wire hookup. As someone else said, I would run a wire from the dryer to a ground somewhere. |
220V dryer sparked on startup (3 wire) What to test?
"Danny D'Amico" wrote in message ... On Thu, 14 Nov 2013 20:39:41 -0500, Ralph Mowery wrote: While the dryer is open look around for any black or burnt areas near wires or the internal electrical parts. Does this look ok from where you sit? http://farm6.staticflickr.com/5474/1...cb94ac7e_o.gif That green wire needs to be terminated on the center terminal. This will bond the dryer to ground (yes, the neutral). If there is a short you will find out pretty quick. |
220V dryer sparked on startup (3 wire) What to test?
"Nightcrawler®" wrote in message ... "Danny D'Amico" wrote in message ... On Thu, 14 Nov 2013 20:39:41 -0500, Ralph Mowery wrote: While the dryer is open look around for any black or burnt areas near wires or the internal electrical parts. Does this look ok from where you sit? http://farm6.staticflickr.com/5474/1...cb94ac7e_o.gif That green wire needs to be terminated on the center terminal. This will bond the dryer to ground (yes, the neutral). If there is a short you will find out pretty quick. I could not tell what the other end of that wire is doing, and assumed that it was not terminated. If, by chance, it is affixed someplace else, make a jumper wire that will go under that screw and terminate it on the center terminal. |
220V dryer sparked on startup (3 wire) What to test?
"Danny D." wrote in message ... On Fri, 15 Nov 2013 22:21:18 +0000, Danny D. wrote: So, I will try to explain what you guys are trying to tell me in the next post (this is too long already). I think you guys are trying to tell me that this third 'thing' goes from the wall to the dryer innards. At the same time, it goes to the dryer steel frame! So, if one of the hot wires were to touch the steel frame, it would go into this third 'thing' and it would go back to the wall. And, from the wall, it would go to the breaker box; and from the breaker box to the power pole; and from the power pole to another, and finally, a pole or three away, it would go into the ground. Back at the dryer, that would mean that the steel case of the dryer is attached to the ground by a long wire of a few hundred feet or more. So, the steel case *could* have a potential on it! (which would be the difference in voltage between the hot wire and the ground a few hundred feet away). I have a simple question that might clear some things up. The two hot wires, are they wrapped around a bare cable that is secured at the house and the power pole? |
220V dryer sparked on startup (3 wire) What to test?
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