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Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work. |
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#41
Posted to rec.crafts.metalworking
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grounding lightbulbs, fuses and other parts
On Monday, July 21, 2014 7:10:30 PM UTC-4, Lloyd E. Sponenburgh wrote:
Gunner Asch fired this volley in : True. Which is why one puts wiring protectors on every pass through point on each stud. One on each side of the stud. Don't waste your breath. These are the same idiots that think you cannot remove a plastic box from the wall without ripping out the drywall. I wonder if they've ever tried to remove a steel box from behind the finish! I wonder if they've ever explored an "old work box" for repairs. These are the same idiots that think 'wattage' corresponds to 'shock potential'. Only you said the word "shock" Obviously, they're dealing with the "mystical electrik fluids" of pre- Faraday times. I like metal boxes, too, for their durability and fastener resistance, but there's not a whit of fact in any of the bull**** they've been spouting. Lloyd |
#42
Posted to rec.crafts.metalworking
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grounding lightbulbs, fuses and other parts
On Tuesday, July 22, 2014 5:00:08 AM UTC-4, jon_banquer wrote:
On Tuesday, July 22, 2014 12:42:55 AM UTC-7, Gunner Asch wrote: On Mon, 21 Jul 2014 18:10:30 -0500, "Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote: Gunner Asch fired this volley in : True. Which is why one puts wiring protectors on every pass through point on each stud. One on each side of the stud. Don't waste your breath. These are the same idiots that think you cannot remove a plastic box from the wall without ripping out the drywall. I wonder if they've ever tried to remove a steel box from behind the finish! I wonder if they've ever explored an "old work box" for repairs. These are the same idiots that think 'wattage' corresponds to 'shock potential'. Obviously, they're dealing with the "mystical electrik fluids" of pre- Faraday times. I like metal boxes, too, for their durability and fastener resistance, but there's not a whit of fact in any of the bull**** they've been spouting. Lloyd Well stated. Gunner -- "Living in the United States now is like being a Tampon. We're in a great place, just at a bad time." No it's not well stated. It's typical Loud bull**** and Mark Wieber ass kissing. jon, I still can't believe anyone would AVOID using metallic cable (MC) and instead use non-metallic cable (Romex) |
#44
Posted to rec.crafts.metalworking
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grounding lightbulbs, fuses and other parts
On Tuesday, July 22, 2014 3:22:39 PM UTC-4, amdx wrote:
On 7/22/2014 2:06 PM, wrote: On Tuesday, July 22, 2014 12:28:45 PM UTC-4, amdx wrote: On 7/20/2014 11:33 AM, wrote: On Saturday, July 19, 2014 5:50:58 PM UTC-4, John G wrote: explained on 20/07/2014 : Where ever it is measured on the property MINUS VAR. Because that's resistance of volt amps. Anything below 5 millivolts is not harmful to persons/property (including VARs). Its in any NEC. In other words, the more metal there is between that 5mv+ and the main panel's box, itself the more potential to a path back (which means less potential for a live person to get in the way) Most of what I snipped was wrong or not understandable. Higher voltages are more apt to deliver more current through your body, PERIOD. One thing I think I see you saying is, you are placing your body as the return line for the 240V device. So if we consider a TV that uses 120 Watts, At 240 volts the TV would draw 500 milliamps, at 120 volts it would draw 1000 milliamps. If you put your body in the return line you might think you are safer at 240 Volts. The resistance of the human body in contact with a electrified metal part can very greatly from 500 ohms immersed in water to 1 million ohms on dry skin. So I'll pick 15,000 ohms for each body/conductor connection, for a total of 30,000 ohms. A 120 Watt, 240 volt TV is equivalent to a 480 ohm resistance. A 120 Watt, 120 Volt TV is equivalent to a 120 ohm resistance. If we add the TV's resistance to the body/conductor connection we get, 30,480 ohms for the 240 Volt circuit, and 30,120 ohms for the 120 Volt circuit. If you do the math, the 240 Volt circuit has a current flow through your body of 7.8 milliamps. The 120 volt circuit has a current flow through your body of 3.98 milliamps. Using your 5mv number 240 Volts is deadly, 120 Volts is not. If I did not understand correctly that your thinking is, "you are placing your body as the return line" then all of the above is still relevant but may not have given you the info you need for understanding. If you don't understand how I did the math to get the numbers please ask and I will type it out. The whole problem is that no one here is mentioning the NEC. Don't use your own figuring. Instead, use examples from the NEC. Discard your "figuring". Here is something from an NEC study guide which is what I meant. "Nonmetallic boxes are not permitted to be used with a metallic wiring method because there is no way to maintain the electrical continuity of the effective ground" -- http://www.mikeholt.com/mojonewsarch...s~20050510.php (2nd question - answer) Here is what you said that many of us disagree with. "Overhead commercial lighting voltage is 277 so its less current and less dangerous" (than a lower voltage, higher current) I added the line in parentheses because I think that is what you meant. Is that correct? What does your link have to do with higher voltages being safer? Mikek To get higher voltage, you have to reduce current (if all from the same service). |
#45
Posted to rec.crafts.metalworking
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grounding lightbulbs, fuses and other parts
On Tuesday, July 22, 2014 3:43:41 PM UTC-4, wrote:
On Tuesday, July 22, 2014 3:22:39 PM UTC-4, amdx wrote: On 7/22/2014 2:06 PM, wrote: On Tuesday, July 22, 2014 12:28:45 PM UTC-4, amdx wrote: On 7/20/2014 11:33 AM, wrote: On Saturday, July 19, 2014 5:50:58 PM UTC-4, John G wrote: explained on 20/07/2014 : Where ever it is measured on the property MINUS VAR. Because that's resistance of volt amps. Anything below 5 millivolts is not harmful to persons/property (including VARs). Its in any NEC. In other words, the more metal there is between that 5mv+ and the main panel's box, itself the more potential to a path back (which means less potential for a live person to get in the way) Most of what I snipped was wrong or not understandable. Higher voltages are more apt to deliver more current through your body, PERIOD. One thing I think I see you saying is, you are placing your body as the return line for the 240V device. So if we consider a TV that uses 120 Watts, At 240 volts the TV would draw 500 milliamps, at 120 volts it would draw 1000 milliamps. If you put your body in the return line you might think you are safer at 240 Volts. The resistance of the human body in contact with a electrified metal part can very greatly from 500 ohms immersed in water to 1 million ohms on dry skin. So I'll pick 15,000 ohms for each body/conductor connection, for a total of 30,000 ohms. A 120 Watt, 240 volt TV is equivalent to a 480 ohm resistance. A 120 Watt, 120 Volt TV is equivalent to a 120 ohm resistance. If we add the TV's resistance to the body/conductor connection we get, 30,480 ohms for the 240 Volt circuit, and 30,120 ohms for the 120 Volt circuit. If you do the math, the 240 Volt circuit has a current flow through your body of 7.8 milliamps. The 120 volt circuit has a current flow through your body of 3.98 milliamps. Using your 5mv number 240 Volts is deadly, 120 Volts is not. If I did not understand correctly that your thinking is, "you are placing your body as the return line" then all of the above is still relevant but may not have given you the info you need for understanding. If you don't understand how I did the math to get the numbers please ask and I will type it out. The whole problem is that no one here is mentioning the NEC. Don't use your own figuring. Instead, use examples from the NEC. Discard your "figuring". Here is something from an NEC study guide which is what I meant. "Nonmetallic boxes are not permitted to be used with a metallic wiring method because there is no way to maintain the electrical continuity of the effective ground" -- http://www.mikeholt.com/mojonewsarch...s~20050510.php (2nd question - answer) Here is what you said that many of us disagree with. "Overhead commercial lighting voltage is 277 so its less current and less dangerous" (than a lower voltage, higher current) I added the line in parentheses because I think that is what you meant. Is that correct? What does your link have to do with higher voltages being safer? Mikek To get higher voltage, you have to reduce current (if all from the same service). High current and low voltage is the danger. (Much moreso than higher voltage and lower current) |
#46
Posted to rec.crafts.metalworking
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grounding lightbulbs, fuses and other parts
On Tuesday, July 22, 2014 12:15:28 PM UTC-7, wrote:
On Tuesday, July 22, 2014 5:00:08 AM UTC-4, jon_banquer wrote: On Tuesday, July 22, 2014 12:42:55 AM UTC-7, Gunner Asch wrote: On Mon, 21 Jul 2014 18:10:30 -0500, "Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote: Gunner Asch fired this volley in : True. Which is why one puts wiring protectors on every pass through point on each stud. One on each side of the stud. Don't waste your breath. These are the same idiots that think you cannot remove a plastic box from the wall without ripping out the drywall. I wonder if they've ever tried to remove a steel box from behind the finish! I wonder if they've ever explored an "old work box" for repairs. These are the same idiots that think 'wattage' corresponds to 'shock potential'. Obviously, they're dealing with the "mystical electrik fluids" of pre- Faraday times. I like metal boxes, too, for their durability and fastener resistance, but there's not a whit of fact in any of the bull**** they've been spouting. Lloyd Well stated. Gunner -- "Living in the United States now is like being a Tampon. We're in a great place, just at a bad time." No it's not well stated. It's typical Loud bull**** and Mark Wieber ass kissing. jon, I still can't believe anyone would AVOID using metallic cable (MC) and instead use non-metallic cable (Romex) America will only start to bet better when short term price isn't the overriding concern. Most of America has lost sight of what the big picture is. |
#47
Posted to rec.crafts.metalworking
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grounding lightbulbs, fuses and other parts
On Tuesday, July 22, 2014 4:12:21 PM UTC-4, jon_banquer wrote:
On Tuesday, July 22, 2014 12:15:28 PM UTC-7, wrote: On Tuesday, July 22, 2014 5:00:08 AM UTC-4, jon_banquer wrote: On Tuesday, July 22, 2014 12:42:55 AM UTC-7, Gunner Asch wrote: On Mon, 21 Jul 2014 18:10:30 -0500, "Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote: Gunner Asch fired this volley in : True. Which is why one puts wiring protectors on every pass through point on each stud. One on each side of the stud. Don't waste your breath. These are the same idiots that think you cannot remove a plastic box from the wall without ripping out the drywall. I wonder if they've ever tried to remove a steel box from behind the finish! I wonder if they've ever explored an "old work box" for repairs. These are the same idiots that think 'wattage' corresponds to 'shock potential'. Obviously, they're dealing with the "mystical electrik fluids" of pre- Faraday times. I like metal boxes, too, for their durability and fastener resistance, but there's not a whit of fact in any of the bull**** they've been spouting. Well stated. No it's not well stated. It's typical Loud bull**** and Mark Wieber ass kissing. jon, I still can't believe anyone would AVOID using metallic cable (MC) and instead use non-metallic cable (Romex) America will only start to bet better when short term price isn't the overriding concern. Most of America has lost sight of what the big picture is. Yeah, but then anti-union, far-right elements of the media would scream "inflation !!", "inflation !!" ,"inflation !!" ,"inflation !!" ,"inflation !!" like they always do during crests. But like I always say to comfort myself, at least most of the other industrialized nations have it right, even if we don't. |
#48
Posted to rec.crafts.metalworking
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grounding lightbulbs, fuses and other parts
On Tuesday, July 22, 2014 1:39:18 PM UTC-7, wrote:
Yeah, but then anti-union, far-right elements of the media would scream "inflation !!", "inflation !!" ,"inflation !!" ,"inflation !!" ,"inflation !!" like they always do during crests. But like I always say to comfort myself, at least most of the other industrialized nations have it right, even if we don't. I see some hope in the rise in awareness by more Americans of who Bernie Sanders and Elizabeth Warren are and what they stand for. The massive incompetency of the current GOP may finally work in the favor of those who want serious change in the direction America is going in. |
#49
Posted to rec.crafts.metalworking
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grounding lightbulbs, fuses and other parts
On 7/22/2014 2:45 PM, wrote:
On Tuesday, July 22, 2014 3:43:41 PM UTC-4, wrote: On Tuesday, July 22, 2014 3:22:39 PM UTC-4, amdx wrote: On 7/22/2014 2:06 PM, wrote: On Tuesday, July 22, 2014 12:28:45 PM UTC-4, amdx wrote: On 7/20/2014 11:33 AM, wrote: On Saturday, July 19, 2014 5:50:58 PM UTC-4, John G wrote: explained on 20/07/2014 : Where ever it is measured on the property MINUS VAR. Because that's resistance of volt amps. Anything below 5 millivolts is not harmful to persons/property (including VARs). Its in any NEC. In other words, the more metal there is between that 5mv+ and the main panel's box, itself the more potential to a path back (which means less potential for a live person to get in the way) Most of what I snipped was wrong or not understandable. Higher voltages are more apt to deliver more current through your body, PERIOD. One thing I think I see you saying is, you are placing your body as the return line for the 240V device. So if we consider a TV that uses 120 Watts, At 240 volts the TV would draw 500 milliamps, at 120 volts it would draw 1000 milliamps. If you put your body in the return line you might think you are safer at 240 Volts. The resistance of the human body in contact with a electrified metal part can very greatly from 500 ohms immersed in water to 1 million ohms on dry skin. So I'll pick 15,000 ohms for each body/conductor connection, for a total of 30,000 ohms. A 120 Watt, 240 volt TV is equivalent to a 480 ohm resistance. A 120 Watt, 120 Volt TV is equivalent to a 120 ohm resistance. If we add the TV's resistance to the body/conductor connection we get, 30,480 ohms for the 240 Volt circuit, and 30,120 ohms for the 120 Volt circuit. If you do the math, the 240 Volt circuit has a current flow through your body of 7.8 milliamps. The 120 volt circuit has a current flow through your body of 3.98 milliamps. Using your 5mv number 240 Volts is deadly, 120 Volts is not. If I did not understand correctly that your thinking is, "you are placing your body as the return line" then all of the above is still relevant but may not have given you the info you need for understanding. If you don't understand how I did the math to get the numbers please ask and I will type it out. The whole problem is that no one here is mentioning the NEC. Don't use your own figuring. Instead, use examples from the NEC. Discard your "figuring". Here is something from an NEC study guide which is what I meant. "Nonmetallic boxes are not permitted to be used with a metallic wiring method because there is no way to maintain the electrical continuity of the effective ground" -- http://www.mikeholt.com/mojonewsarch...s~20050510.php (2nd question - answer) Here is what you said that many of us disagree with. "Overhead commercial lighting voltage is 277 so its less current and less dangerous" (than a lower voltage, higher current) I added the line in parentheses because I think that is what you meant. Is that correct? What does your link have to do with higher voltages being safer? Mikek To get higher voltage, you have to reduce current (if all from the same service). High current and low voltage is the danger. (Much moreso than higher voltage and lower current) Now I think you are just pulling my leg. But just in case, how many people are electrocuted from an automobile electrical system. LOw voltage hundreds of amps. Seriously, do you believe " High current and low voltage is the danger" If so I'll continue to work with you. Do you know ohms law? Do you understand that for a fixed resistance, current is totally dependent on voltage? Mikek |
#50
Posted to rec.crafts.metalworking
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grounding lightbulbs, fuses and other parts
amdx fired this volley in news:lqmpms$icm$1@dont-
email.me: Seriously, do you believe " High current and low voltage is the danger" If so I'll continue to work with you. Do you know ohms law? Do you understand that for a fixed resistance, current is totally dependent on voltage? No, he doesn't. He also doesn't seem to understand that 277VAC service has the potential (G) to deliver way more than the 5ma the human body model responds to (adversely). One might wonder why they would use high voltage for an electric chair (well... not _really_ high... 500-2000V), if lower voltage (higher current!snicker) would be more deadly. But then, this idiot is just Jonniefag Bank-less in other clothes. HEH! He even carries on conversations with himself in his posts! G Lloyd |
#51
Posted to rec.crafts.metalworking
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grounding lightbulbs, fuses and other parts
On 7/22/2014 6:06 PM, Lloyd E. Sponenburgh wrote:
amdx fired this volley in news:lqmpms$icm$1@dont- email.me: Seriously, do you believe " High current and low voltage is the danger" If so I'll continue to work with you. Do you know ohms law? Do you understand that for a fixed resistance, current is totally dependent on voltage? No, he doesn't. It seems he doesn't but I'll wait for him to respond. He also doesn't seem to understand that 277VAC service has the potential (G) to deliver way more than the 5ma the human body model responds to (adversely). Yes, his writings would suggest that, when he responds, I'll see if I can walk him through ohms law, to show him how it works. I thought my long winded explanation was pretty good, but if you don't know ohms law, you won't know where the numbers come from, so it wouldn't make sense. Mikek |
#52
Posted to rec.crafts.metalworking
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grounding lightbulbs, fuses and other parts
amdx fired this volley in news:lqmt9f$6sl$1@dont-
email.me: Yes, his writings would suggest that, when he responds, You won't really succeed at convincing this particular person of anything. He is truly insane, destitute, and socially inept. He's a mentally- disabled welfare patient, living on the dole. If you attempt to correct or teach him anything, he will disparage you with vicious cursing, insistances of his superior knowlege, and inane (very) comparisons to himself. Don't waste your breath unless he begs instruction -- and then be ready for the repercussions. Lloyd |
#53
Posted to rec.crafts.metalworking
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grounding lightbulbs, fuses and other parts
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#54
Posted to rec.crafts.metalworking
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grounding lightbulbs, fuses and other parts
amdx fired this volley in
: Hmm... If you have rubber sole shoes the all metal boxes and metal conduit could be what kills you. if you touch the grounded light fixture, the electrical box or the conduit while you are in contact with the hot wire, it could kill you. If it was all plastic and you touched it while in contact with the hot wire, you probably wouldn't even feel it. NO! Really? I guess the next thing you'll say (G) is that it's not 5mV, but 5mA _current_ through the heart muscle that can cause a problem? Maybe you could comment on removing a plastic box from the wall without pulling off "all the drywall". (can anyone say "recip saw with a thin blade that will cut two common 10d nails?) G I'm glad you decided to comment. You sound like you just might have some practical electrical knowledge. Lloyd |
#55
Posted to rec.crafts.metalworking
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grounding lightbulbs, fuses and other parts
On 7/22/2014 8:11 PM, amdx wrote:
1 Hmm... If you have rubber sole shoes the all metal boxes and metal conduit could be what kills you. if you touch the grounded light fixture, the electrical box or the conduit while you are in contact with the hot wire, it could kill you. If it was all plastic and you touched it while in contact with the hot wire, you probably wouldn't even feel it. Mikek One is supposed to keep the left hand in a pocket. Keeping hand to hand killing current out of the picture. I don't see an electrician putting a finger in a socket and grounding his other hand. That is a set up condition. Not going to happen. Getting a shock across a finger won't kill you. Getting a shock across two fingers won't kill you. The rubber soles prevent current flow through the feet therefore they prevent current across the heart or lungs. Only hand to hand is left. Stand on the right foot and use the right hand. No heart issue. A metal box by law must be grounded to the third wire. AKA green or green/yellow. The black is the killer wire - aka black death The white is the saving wire - aka angel of care. one could take a hit through a foot and a sweaty T-shirt trickle. (rare). Martin |
#56
Posted to rec.crafts.metalworking
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grounding lightbulbs, fuses and other parts
On 2014-07-21, Martin Eastburn wrote:
On 7/20/2014 7:50 AM, Larry Jaques wrote: On 20 Jul 2014 00:52:54 GMT, "DoN. Nichols" wrote: [ ... ] And, while the initial resistance will be a function mostly of the moisture and salinity of the hands contacting the voltage source, once the initial current starts to flow, the skin breaks down and the resistance drops rapidly -- and the more the voltage, the more rapidly the resistance drops. And the current needed for a fatal dosage is well below the trip current levels of commercial circuit breakers. (I do have some glass cartridge fuses rated at 1/100 Amp (10 mA) which should be enough to protect you -- but not enough to allow most equipment to operate, so that is why I still have those fuses unused. :-) Anecdotally, 240 is safer because it will kick you off more quickly than 120v. Yes -- depending on the orientation of your hand. If you touch the palm, you are more likely to grip firmly onto the source of the electricity and soon be deal. If you fall into wires and complete the circuit, you'll be dead more quickly, but brushes against it are, IMHO, safer, and I'd rather work with 240 than 120 for that reason. 5mil nitrile gloves are a part of my DVM package, and I wear them when working with live circuits. You can feel the voltage start to bite through them and move your mostly-water body parts quickly out of contact. When convenient (maybe 1/4 to 1/3 of the time), I shut off the breaker. I have a healthy respect for deadly but wonderful electricity. CAVEAT: Kids, don't try this at home. Amen! My worst zap was from a 2 KV bank of capacitors (200 uF total) connected to a pair of transformers which could recharge the caps in 100 mS from a full discharge. That one got me from my index finger on my left hand through my body to the right elbow (which was resting on a old Tektronix tube 'scope. I spent what felt like five minutes looking for my heartbeat, before I realized that that noise which was getting in the way *was* my heartbeat. Sortly after that, I arranged for the whole team to get CPR training. :-) -- Liberalism is the result of severe pathogens in our society. I had a friend years ago who's dad was a licensed electrician. Actually 2. Taught Electronics and dads push the 'new' stuff on the kids. Anyway he was working in the Engineering building and with the cover off a 880v 3 phase box - he was working the box hot. Normal. Power down all sorts of expensive machines on those lines... He dropped his screwdriver down into the panel. Vaporized the steel, plated his face and upper body - his glasses in side of his goggles saved his eyes. He was in tough shape for a month or so at the hospital. Ouch! Yes, sometimes, it is necessary to work on live circuits -- as the only way to tell what they are doing. But when there is *that* much power, I would really prefer to find some other way to do it. :-) One has to be careful. Now they sell Be metal drivers and coated drivers. O.K. I have to ask what the benefit of the Be (I presume actually BeCu non-sparking tools), but I can't imagine the vapor from them falling into a high power arc would be that much lower in temperature, and given the hazards in machining BeCu, I can't imagine that the vapor from that would be any too healthy compared to vaporized steel. The real place which I know of BeCu tools being preferred is when working in an explosive atmosphere, as they don't generate sparks when they hit other metals, while steel (especially hardened steel) does -- thus being likely to ignite the explosive mixture. Enjoy, DoN. -- Remove oil spill source from e-mail Email: | (KV4PH) Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- |
#57
Posted to rec.crafts.metalworking
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grounding lightbulbs, fuses and other parts
On Tue, 22 Jul 2014 21:59:28 -0500, Martin Eastburn
wrote: On 7/22/2014 8:11 PM, amdx wrote: 1 Hmm... If you have rubber sole shoes the all metal boxes and metal conduit could be what kills you. if you touch the grounded light fixture, the electrical box or the conduit while you are in contact with the hot wire, it could kill you. If it was all plastic and you touched it while in contact with the hot wire, you probably wouldn't even feel it. Mikek One is supposed to keep the left hand in a pocket. Keeping hand to hand killing current out of the picture. I don't see an electrician putting a finger in a socket and grounding his other hand. That is a set up condition. Not going to happen. Getting a shock across a finger won't kill you. Getting a shock across two fingers won't kill you. The rubber soles prevent current flow through the feet therefore they prevent current across the heart or lungs. Only hand to hand is left. Stand on the right foot and use the right hand. No heart issue. A metal box by law must be grounded to the third wire. AKA green or green/yellow. The black is the killer wire - aka black death The white is the saving wire - aka angel of care. one could take a hit through a foot and a sweaty T-shirt trickle. (rare). Martin Right! One hand in the pocket.... when you are on the top of a 20 ft. ladder. -- Cheers, M.Y.Aquila |
#58
Posted to rec.crafts.metalworking
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grounding lightbulbs, fuses and other parts
On 23 Jul 2014 04:21:03 GMT, "DoN. Nichols"
wrote: On 2014-07-21, Martin Eastburn wrote: On 7/20/2014 7:50 AM, Larry Jaques wrote: On 20 Jul 2014 00:52:54 GMT, "DoN. Nichols" wrote: [ ... ] And, while the initial resistance will be a function mostly of the moisture and salinity of the hands contacting the voltage source, once the initial current starts to flow, the skin breaks down and the resistance drops rapidly -- and the more the voltage, the more rapidly the resistance drops. And the current needed for a fatal dosage is well below the trip current levels of commercial circuit breakers. (I do have some glass cartridge fuses rated at 1/100 Amp (10 mA) which should be enough to protect you -- but not enough to allow most equipment to operate, so that is why I still have those fuses unused. :-) Anecdotally, 240 is safer because it will kick you off more quickly than 120v. Yes -- depending on the orientation of your hand. If you touch the palm, you are more likely to grip firmly onto the source of the electricity and soon be deal. If you fall into wires and complete the circuit, you'll be dead more quickly, but brushes against it are, IMHO, safer, and I'd rather work with 240 than 120 for that reason. 5mil nitrile gloves are a part of my DVM package, and I wear them when working with live circuits. You can feel the voltage start to bite through them and move your mostly-water body parts quickly out of contact. When convenient (maybe 1/4 to 1/3 of the time), I shut off the breaker. I have a healthy respect for deadly but wonderful electricity. CAVEAT: Kids, don't try this at home. Amen! My worst zap was from a 2 KV bank of capacitors (200 uF total) connected to a pair of transformers which could recharge the caps in 100 mS from a full discharge. That one got me from my index finger on my left hand through my body to the right elbow (which was resting on a old Tektronix tube 'scope. I spent what felt like five minutes looking for my heartbeat, before I realized that that noise which was getting in the way *was* my heartbeat. Sortly after that, I arranged for the whole team to get CPR training. :-) -- Liberalism is the result of severe pathogens in our society. I had a friend years ago who's dad was a licensed electrician. Actually 2. Taught Electronics and dads push the 'new' stuff on the kids. Anyway he was working in the Engineering building and with the cover off a 880v 3 phase box - he was working the box hot. Normal. Power down all sorts of expensive machines on those lines... He dropped his screwdriver down into the panel. Vaporized the steel, plated his face and upper body - his glasses in side of his goggles saved his eyes. He was in tough shape for a month or so at the hospital. Ouch! Yes, sometimes, it is necessary to work on live circuits -- as the only way to tell what they are doing. But when there is *that* much power, I would really prefer to find some other way to do it. :-) One has to be careful. Now they sell Be metal drivers and coated drivers. O.K. I have to ask what the benefit of the Be (I presume actually BeCu non-sparking tools), but I can't imagine the vapor from them falling into a high power arc would be that much lower in temperature, and given the hazards in machining BeCu, I can't imagine that the vapor from that would be any too healthy compared to vaporized steel. The real place which I know of BeCu tools being preferred is when working in an explosive atmosphere, as they don't generate sparks when they hit other metals, while steel (especially hardened steel) does -- thus being likely to ignite the explosive mixture. Enjoy, DoN. My hand tools..screw drivers mostly..that are used on subpanels etc etc..ALL..ALL..EVERYONE has the shanks covered up with heat shrink tubing all the way to the handles..with just the tip of the screwdriver/nutdriver...sticking out. I crossed a couple busses once with a bare screw driver blade and melted it and the busses down. Heat shrink tubing is very..very cheap protection Gunner -- "Living in the United States now is like being a Tampon. We're in a great place, just at a bad time." |
#59
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grounding lightbulbs, fuses and other parts
On Tue, 22 Jul 2014 13:39:18 -0700 (PDT),
wrote: America will only start to bet better when short term price isn't the overriding concern. Most of America has lost sight of what the big picture is. Yeah, but then anti-union, far-right elements of the media would scream "inflation !!", "inflation !!" ,"inflation !!" ,"inflation !!" ,"inflation !!" like they always do during crests. Which Anti-union , far right media are you talking about? You mean there actually IS such a thing???? Which one is it? ABC? CBS? NBC? CNN? But like I always say to comfort myself, at least most of the other industrialized nations have it right, even if we don't. What other industrialized nations are you chattering about? These? http://www.statista.com/statistics/2...-eu-countries/ One should note..that those numbers are the U3 numbers..not the U6 numbers So if you at the least..double the numbers listed..it will be far closer to accurate If you notice the corrected data from 2011...you will see exactly what U6 means http://rwer.wordpress.com/2011/11/13...-europe-chart/ Our current U6 rates...updated within the last day http://www.macrotrends.net/1377/u6-unemployment-rate As you will notice..Europe is in as big a ******** as we are. Gunner -- "Living in the United States now is like being a Tampon. We're in a great place, just at a bad time." |
#60
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#61
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grounding lightbulbs, fuses and other parts
Gunner Asch on Wed, 23 Jul 2014 03:23:32 -0700
typed in rec.crafts.metalworking the following: One has to be careful. Now they sell Be metal drivers and coated drivers. O.K. I have to ask what the benefit of the Be (I presume actually BeCu non-sparking tools), but I can't imagine the vapor from them falling into a high power arc would be that much lower in temperature, and given the hazards in machining BeCu, I can't imagine that the vapor from that would be any too healthy compared to vaporized steel. The real place which I know of BeCu tools being preferred is when working in an explosive atmosphere, as they don't generate sparks when they hit other metals, while steel (especially hardened steel) does -- thus being likely to ignite the explosive mixture. Enjoy, DoN. My hand tools..screw drivers mostly..that are used on subpanels etc etc..ALL..ALL..EVERYONE has the shanks covered up with heat shrink tubing all the way to the handles..with just the tip of the screwdriver/nutdriver...sticking out. I crossed a couple busses once with a bare screw driver blade and melted it and the busses down. Heat shrink tubing is very..very cheap protection Much neater than duct tape - which I've used. -- pyotr filipivich "With Age comes Wisdom. Although more often, Age travels alone." |
#62
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grounding lightbulbs, fuses and other parts
pyotr filipivich fired this volley in
news Heat shrink tubing is very..very cheap protection Much neater than duct tape - which I've used. In either case, several layers are called for, if you're doing 'vigorous' work. One layer might pierce easily on a sharp edge... and EVERYTHING inside a distribution box is stamped, with sharp edged. Lloyd |
#63
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grounding lightbulbs, fuses and other parts
On Tuesday, July 22, 2014 6:47:48 PM UTC-4, amdx wrote:
On 7/22/2014 2:45 PM, wrote: On Tuesday, July 22, 2014 3:43:41 PM UTC-4, wrote: On Tuesday, July 22, 2014 3:22:39 PM UTC-4, amdx wrote: On 7/22/2014 2:06 PM, wrote: On Tuesday, July 22, 2014 12:28:45 PM UTC-4, amdx wrote: On 7/20/2014 11:33 AM, wrote: On Saturday, July 19, 2014 5:50:58 PM UTC-4, John G wrote: explained on 20/07/2014 : Where ever it is measured on the property MINUS VAR. Because that's resistance of volt amps. Anything below 5 millivolts is not harmful to persons/property (including VARs). Its in any NEC. In other words, the more metal there is between that 5mv+ and the main panel's box, itself the more potential to a path back (which means less potential for a live person to get in the way) Most of what I snipped was wrong or not understandable. Higher voltages are more apt to deliver more current through your body, PERIOD. One thing I think I see you saying is, you are placing your body as the return line for the 240V device. So if we consider a TV that uses 120 Watts, At 240 volts the TV would draw 500 milliamps, at 120 volts it would draw 1000 milliamps. If you put your body in the return line you might think you are safer at 240 Volts. The resistance of the human body in contact with a electrified metal part can very greatly from 500 ohms immersed in water to 1 million ohms on dry skin. So I'll pick 15,000 ohms for each body/conductor connection, for a total of 30,000 ohms. A 120 Watt, 240 volt TV is equivalent to a 480 ohm resistance. A 120 Watt, 120 Volt TV is equivalent to a 120 ohm resistance. If we add the TV's resistance to the body/conductor connection we get, 30,480 ohms for the 240 Volt circuit, and 30,120 ohms for the 120 Volt circuit. If you do the math, the 240 Volt circuit has a current flow through your body of 7.8 milliamps. The 120 volt circuit has a current flow through your body of 3.98 milliamps. Using your 5mv number 240 Volts is deadly, 120 Volts is not. If I did not understand correctly that your thinking is, "you are placing your body as the return line" then all of the above is still relevant but may not have given you the info you need for understanding. If you don't understand how I did the math to get the numbers please ask and I will type it out. The whole problem is that no one here is mentioning the NEC. Don't use your own figuring. Instead, use examples from the NEC. Discard your "figuring". Here is something from an NEC study guide which is what I meant. "Nonmetallic boxes are not permitted to be used with a metallic wiring method because there is no way to maintain the electrical continuity of the effective ground" -- http://www.mikeholt.com/mojonewsarch...s~20050510.php (2nd question - answer) Here is what you said that many of us disagree with. "Overhead commercial lighting voltage is 277 so its less current and less dangerous" (than a lower voltage, higher current) I added the line in parentheses because I think that is what you meant. Is that correct? What does your link have to do with higher voltages being safer? Mikek To get higher voltage, you have to reduce current (if all from the same service). High current and low voltage is the danger. (Much moreso than higher voltage and lower current) Now I think you are just pulling my leg. But just in case, how many Your unwillingness to even mention anything about the NEC shows me you are just pulling mine. In any completed Kilowatt Hour service supply, the higher the voltage, yes, the lower the current. I don't need your opinions on ohms law, BTW) |
#64
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grounding lightbulbs, fuses and other parts
On Tuesday, July 22, 2014 7:48:56 PM UTC-4, amdx wrote:
On 7/22/2014 6:06 PM, Lloyd E. Sponenburgh wrote: amdx fired this volley in news:lqmpms$icm$1@dont- email.me: Seriously, do you believe " High current and low voltage is the danger" If so I'll continue to work with you. Do you know ohms law? Do you understand that for a fixed resistance, current is totally dependent on voltage? No, he doesn't. It seems he doesn't but I'll wait for him to respond. He also doesn't seem to understand that 277VAC service has the potential (G) to deliver way more than the 5ma the human body model responds to (adversely). Yes, his writings would suggest that, when he responds, I'll see if I can walk him through ohms law, to show him how it works. How can you show anyone what ohm's law does if you can't even accept that transformed higher voltage means lower current and vice-versa? (and what part of your own writings show that you are even familiar with NEC?) |
#65
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grounding lightbulbs, fuses and other parts
On Tuesday, July 22, 2014 8:00:53 PM UTC-4, Lloyd E. Sponenburgh wrote:
amdx fired this volley in news:lqmt9f$6sl$1@dont- email.me: Yes, his writings would suggest that, when he responds, You won't really succeed at convincing this particular person of anything. He is truly insane, destitute, and socially inept. He's a mentally- disabled welfare patient, living on the dole. I bet I do more work in a day than a senile person like you does all week. You don't even know the value of Linux. That says it all right there. |
#66
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grounding lightbulbs, fuses and other parts
On 7/23/2014 2:37 PM, wrote:
On Tuesday, July 22, 2014 7:48:56 PM UTC-4, amdx wrote: On 7/22/2014 6:06 PM, Lloyd E. Sponenburgh wrote: amdx fired this volley in news:lqmpms$icm$1@dont- email.me: Seriously, do you believe " High current and low voltage is the danger" If so I'll continue to work with you. Do you know ohms law? Do you understand that for a fixed resistance, current is totally dependent on voltage? No, he doesn't. It seems he doesn't but I'll wait for him to respond. He also doesn't seem to understand that 277VAC service has the potential (G) to deliver way more than the 5ma the human body model responds to (adversely). Yes, his writings would suggest that, when he responds, I'll see if I can walk him through ohms law, to show him how it works. How can you show anyone what ohm's law does if you can't even accept that transformed higher voltage means lower current and vice-versa? You haven't completed that sentence. If you are distributing power, a higher voltage line can deliver the same amount of power at a lower current than a lower voltage line. But you will be killed by a 330kV line easier than a 120 volt line. That ay be why they put 330kV lines on tall towers and put 120 volts in your house. If you are talking about connecting a 240 volt line to your left hand and grounding you right hand vs doing the same with a 120 volt line, more current will flow with higher 240 volt line. I got into the discussion when you said, "Overhead commercial lighting voltage is 277 so its less current and less dangerous," So to rephrase you said, 277 volts is less dangerous than a lower voltage. Do you still think this? Mikek --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com |
#67
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grounding lightbulbs, fuses and other parts
wrote in message
... On Tuesday, July 22, 2014 6:47:48 PM UTC-4, amdx wrote: On 7/22/2014 2:45 PM, wrote: On Tuesday, July 22, 2014 3:43:41 PM UTC-4, wrote: On Tuesday, July 22, 2014 3:22:39 PM UTC-4, amdx wrote: On 7/22/2014 2:06 PM, wrote: On Tuesday, July 22, 2014 12:28:45 PM UTC-4, amdx wrote: On 7/20/2014 11:33 AM, wrote: On Saturday, July 19, 2014 5:50:58 PM UTC-4, John G wrote: explained on 20/07/2014 : Your unwillingness to even mention anything about the NEC shows me you are just pulling mine. In any completed Kilowatt Hour service supply, the higher the voltage, yes, the lower the current. I don't need your opinions on ohms law, BTW) For a given load horsepower, yes a higher voltage results in a lower current -demand-, but whatever its voltage the supply transformer can still deliver enough current to cause a very destructive vaporized-metal explosion if you short the lines. http://www.ci.longmont.co.us/lpc/con...ult_charts.htm Even the pole transformer feeding your house can supply over 5,000 Amps if shorted. I needed to know the short-circuit current to specify a fuse or circuit breaker with an appropriate interrupting rating. http://ecmweb.com/content/understand...eaker-markings "If the breaker doesn't have a suitable interrupting rating for the available fault current, it could explode while attempting to clear a fault,..." The UL tests to confirm breaker interrupting rating are spectacular fountains of fire. Fuses have voltage as well as current ratings based on the internal arc they can extinguish. -jsw, once tasked to ensure that custom electrical equipment shipped overseas met the appropriate CSA, Ontario Hydro, NEMKO/SEMKO/DEMKO, TUV etc safety requirements. Meeting NEC and UL requirements doesn't guarantee compliance elsewhere, for example Norway wanted a list of all cadmium- and nickel-plated hardware. Before RoHS they couldn't exclude them, but they could make using them annoying. |
#68
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grounding lightbulbs, fuses and other parts
On 7/23/2014 5:36 AM, Gunner Asch wrote:
No knum nuts - One puts the hand in pocket when the other is in the hot zone. One can hold onto a ladder with one arm and in a pocket if you don't have belts to do it for you. Just don't get one hand on ground and the other on a hot. That is the point. Martin Right! One hand in the pocket.... when you are on the top of a 20 ft. ladder. And making up wire nuts...... -- "Living in the United States now is like being a Tampon. We're in a great place, just at a bad time." |
#69
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grounding lightbulbs, fuses and other parts
On Wednesday, July 23, 2014 8:15:26 PM UTC-7, Martin Eastburn wrote:
On 7/23/2014 5:36 AM, Gunner Asch wrote: No knum nuts - One puts the hand in pocket when the other is in the hot zone. One can hold onto a ladder with one arm and in a pocket if you don't have belts to do it for you. Just don't get one hand on ground and the other on a hot. That is the point. Martin Right! One hand in the pocket.... when you are on the top of a 20 ft. ladder. And making up wire nuts...... -- "Living in the United States now is like being a Tampon. We're in a great place, just at a bad time." Mark Wieber doesn't have any nuts. I ripped them off and shoved them down his throat. |
#70
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grounding lightbulbs, fuses and other parts
On 7/22/2014 11:21 PM, DoN. Nichols wrote:
On 2014-07-21, Martin Eastburn wrote: On 7/20/2014 7:50 AM, Larry Jaques wrote: On 20 Jul 2014 00:52:54 GMT, "DoN. Nichols" wrote: [ ... ] And, while the initial resistance will be a function mostly of the moisture and salinity of the hands contacting the voltage source, once the initial current starts to flow, the skin breaks down and the resistance drops rapidly -- and the more the voltage, the more rapidly the resistance drops. And the current needed for a fatal dosage is well below the trip current levels of commercial circuit breakers. (I do have some glass cartridge fuses rated at 1/100 Amp (10 mA) which should be enough to protect you -- but not enough to allow most equipment to operate, so that is why I still have those fuses unused. :-) Anecdotally, 240 is safer because it will kick you off more quickly than 120v. Yes -- depending on the orientation of your hand. If you touch the palm, you are more likely to grip firmly onto the source of the electricity and soon be deal. If you fall into wires and complete the circuit, you'll be dead more quickly, but brushes against it are, IMHO, safer, and I'd rather work with 240 than 120 for that reason. 5mil nitrile gloves are a part of my DVM package, and I wear them when working with live circuits. You can feel the voltage start to bite through them and move your mostly-water body parts quickly out of contact. When convenient (maybe 1/4 to 1/3 of the time), I shut off the breaker. I have a healthy respect for deadly but wonderful electricity. CAVEAT: Kids, don't try this at home. Amen! My worst zap was from a 2 KV bank of capacitors (200 uF total) connected to a pair of transformers which could recharge the caps in 100 mS from a full discharge. That one got me from my index finger on my left hand through my body to the right elbow (which was resting on a old Tektronix tube 'scope. I spent what felt like five minutes looking for my heartbeat, before I realized that that noise which was getting in the way *was* my heartbeat. Sortly after that, I arranged for the whole team to get CPR training. :-) -- Liberalism is the result of severe pathogens in our society. I had a friend years ago who's dad was a licensed electrician. Actually 2. Taught Electronics and dads push the 'new' stuff on the kids. Anyway he was working in the Engineering building and with the cover off a 880v 3 phase box - he was working the box hot. Normal. Power down all sorts of expensive machines on those lines... He dropped his screwdriver down into the panel. Vaporized the steel, plated his face and upper body - his glasses in side of his goggles saved his eyes. He was in tough shape for a month or so at the hospital. Ouch! Yes, sometimes, it is necessary to work on live circuits -- as the only way to tell what they are doing. But when there is *that* much power, I would really prefer to find some other way to do it. :-) One has to be careful. Now they sell Be metal drivers and coated drivers. O.K. I have to ask what the benefit of the Be (I presume actually BeCu non-sparking tools), but I can't imagine the vapor from them falling into a high power arc would be that much lower in temperature, and given the hazards in machining BeCu, I can't imagine that the vapor from that would be any too healthy compared to vaporized steel. The real place which I know of BeCu tools being preferred is when working in an explosive atmosphere, as they don't generate sparks when they hit other metals, while steel (especially hardened steel) does -- thus being likely to ignite the explosive mixture. Enjoy, DoN. IIRC BeCu tools are non-conductive. They won't cause an arc (explode gas) if shorted across terminals. We used bronze in the paint shop at GM, but that was in the late 60's. I was plant security the summer between college and contract work. Martin |
#71
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grounding lightbulbs, fuses and other parts
On Wed, 23 Jul 2014 22:24:22 -0500, Martin Eastburn
wrote: On 7/22/2014 11:21 PM, DoN. Nichols wrote: On 2014-07-21, Martin Eastburn wrote: On 7/20/2014 7:50 AM, Larry Jaques wrote: On 20 Jul 2014 00:52:54 GMT, "DoN. Nichols" wrote: [ ... ] And, while the initial resistance will be a function mostly of the moisture and salinity of the hands contacting the voltage source, once the initial current starts to flow, the skin breaks down and the resistance drops rapidly -- and the more the voltage, the more rapidly the resistance drops. And the current needed for a fatal dosage is well below the trip current levels of commercial circuit breakers. (I do have some glass cartridge fuses rated at 1/100 Amp (10 mA) which should be enough to protect you -- but not enough to allow most equipment to operate, so that is why I still have those fuses unused. :-) Anecdotally, 240 is safer because it will kick you off more quickly than 120v. Yes -- depending on the orientation of your hand. If you touch the palm, you are more likely to grip firmly onto the source of the electricity and soon be deal. If you fall into wires and complete the circuit, you'll be dead more quickly, but brushes against it are, IMHO, safer, and I'd rather work with 240 than 120 for that reason. 5mil nitrile gloves are a part of my DVM package, and I wear them when working with live circuits. You can feel the voltage start to bite through them and move your mostly-water body parts quickly out of contact. When convenient (maybe 1/4 to 1/3 of the time), I shut off the breaker. I have a healthy respect for deadly but wonderful electricity. CAVEAT: Kids, don't try this at home. Amen! My worst zap was from a 2 KV bank of capacitors (200 uF total) connected to a pair of transformers which could recharge the caps in 100 mS from a full discharge. That one got me from my index finger on my left hand through my body to the right elbow (which was resting on a old Tektronix tube 'scope. I spent what felt like five minutes looking for my heartbeat, before I realized that that noise which was getting in the way *was* my heartbeat. Sortly after that, I arranged for the whole team to get CPR training. :-) -- Liberalism is the result of severe pathogens in our society. I had a friend years ago who's dad was a licensed electrician. Actually 2. Taught Electronics and dads push the 'new' stuff on the kids. Anyway he was working in the Engineering building and with the cover off a 880v 3 phase box - he was working the box hot. Normal. Power down all sorts of expensive machines on those lines... He dropped his screwdriver down into the panel. Vaporized the steel, plated his face and upper body - his glasses in side of his goggles saved his eyes. He was in tough shape for a month or so at the hospital. Ouch! Yes, sometimes, it is necessary to work on live circuits -- as the only way to tell what they are doing. But when there is *that* much power, I would really prefer to find some other way to do it. :-) One has to be careful. Now they sell Be metal drivers and coated drivers. O.K. I have to ask what the benefit of the Be (I presume actually BeCu non-sparking tools), but I can't imagine the vapor from them falling into a high power arc would be that much lower in temperature, and given the hazards in machining BeCu, I can't imagine that the vapor from that would be any too healthy compared to vaporized steel. The real place which I know of BeCu tools being preferred is when working in an explosive atmosphere, as they don't generate sparks when they hit other metals, while steel (especially hardened steel) does -- thus being likely to ignite the explosive mixture. Enjoy, DoN. IIRC BeCu tools are non-conductive. They won't cause an arc (explode gas) if shorted across terminals. We used bronze in the paint shop at GM, but that was in the late 60's. I was plant security the summer between college and contract work. Martin Nope. Beryllium copper alloys are high conductive materials. Bronze is an allow of Tin and copper. The U.S. Air force once issued beryllium copper tools for work on airplanes as they are non-sparking. Sometime later they went to great lengths to recover them from all tool boxes as the beryllium was said to be toxic. I definitely remember the notice that Beryllium copper tools were to be immediately turned into Supply for replacement. -- Cheers, John B. |
#72
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grounding lightbulbs, fuses and other parts
On Wed, 23 Jul 2014 22:15:26 -0500, Martin Eastburn
wrote: On 7/23/2014 5:36 AM, Gunner Asch wrote: No knum nuts - One puts the hand in pocket when the other is in the hot zone. One can hold onto a ladder with one arm and in a pocket if you don't have belts to do it for you. Just don't get one hand on ground and the other on a hot. That is the point. It sounds very plausible until you actually get to the top of the 20 foot ladder and discover that you have to stand on the top rung to reach. Of course, you could go down to Home Pro and buy a new 25 ft. ladder but you've only got this single connection to make and you're done with this stinking job.... Martin Right! One hand in the pocket.... when you are on the top of a 20 ft. ladder. And making up wire nuts...... -- "Living in the United States now is like being a Tampon. We're in a great place, just at a bad time." -- Cheers, John B. |
#73
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grounding lightbulbs, fuses and other parts
On Thu, 24 Jul 2014 11:52:46 +0700, John B. Slocomb
wrote: On Wed, 23 Jul 2014 22:24:22 -0500, Martin Eastburn wrote: On 7/22/2014 11:21 PM, DoN. Nichols wrote: On 2014-07-21, Martin Eastburn wrote: On 7/20/2014 7:50 AM, Larry Jaques wrote: On 20 Jul 2014 00:52:54 GMT, "DoN. Nichols" wrote: [ ... ] And, while the initial resistance will be a function mostly of the moisture and salinity of the hands contacting the voltage source, once the initial current starts to flow, the skin breaks down and the resistance drops rapidly -- and the more the voltage, the more rapidly the resistance drops. And the current needed for a fatal dosage is well below the trip current levels of commercial circuit breakers. (I do have some glass cartridge fuses rated at 1/100 Amp (10 mA) which should be enough to protect you -- but not enough to allow most equipment to operate, so that is why I still have those fuses unused. :-) Anecdotally, 240 is safer because it will kick you off more quickly than 120v. Yes -- depending on the orientation of your hand. If you touch the palm, you are more likely to grip firmly onto the source of the electricity and soon be deal. If you fall into wires and complete the circuit, you'll be dead more quickly, but brushes against it are, IMHO, safer, and I'd rather work with 240 than 120 for that reason. 5mil nitrile gloves are a part of my DVM package, and I wear them when working with live circuits. You can feel the voltage start to bite through them and move your mostly-water body parts quickly out of contact. When convenient (maybe 1/4 to 1/3 of the time), I shut off the breaker. I have a healthy respect for deadly but wonderful electricity. CAVEAT: Kids, don't try this at home. Amen! My worst zap was from a 2 KV bank of capacitors (200 uF total) connected to a pair of transformers which could recharge the caps in 100 mS from a full discharge. That one got me from my index finger on my left hand through my body to the right elbow (which was resting on a old Tektronix tube 'scope. I spent what felt like five minutes looking for my heartbeat, before I realized that that noise which was getting in the way *was* my heartbeat. Sortly after that, I arranged for the whole team to get CPR training. :-) -- Liberalism is the result of severe pathogens in our society. I had a friend years ago who's dad was a licensed electrician. Actually 2. Taught Electronics and dads push the 'new' stuff on the kids. Anyway he was working in the Engineering building and with the cover off a 880v 3 phase box - he was working the box hot. Normal. Power down all sorts of expensive machines on those lines... He dropped his screwdriver down into the panel. Vaporized the steel, plated his face and upper body - his glasses in side of his goggles saved his eyes. He was in tough shape for a month or so at the hospital. Ouch! Yes, sometimes, it is necessary to work on live circuits -- as the only way to tell what they are doing. But when there is *that* much power, I would really prefer to find some other way to do it. :-) One has to be careful. Now they sell Be metal drivers and coated drivers. O.K. I have to ask what the benefit of the Be (I presume actually BeCu non-sparking tools), but I can't imagine the vapor from them falling into a high power arc would be that much lower in temperature, and given the hazards in machining BeCu, I can't imagine that the vapor from that would be any too healthy compared to vaporized steel. The real place which I know of BeCu tools being preferred is when working in an explosive atmosphere, as they don't generate sparks when they hit other metals, while steel (especially hardened steel) does -- thus being likely to ignite the explosive mixture. Enjoy, DoN. IIRC BeCu tools are non-conductive. They won't cause an arc (explode gas) if shorted across terminals. We used bronze in the paint shop at GM, but that was in the late 60's. I was plant security the summer between college and contract work. Martin Nope. Beryllium copper alloys are high conductive materials. Bronze is an allow of Tin and copper. Alloy is not spelled "allow", even when it contains beryllium :-) The U.S. Air force once issued beryllium copper tools for work on airplanes as they are non-sparking. Sometime later they went to great lengths to recover them from all tool boxes as the beryllium was said to be toxic. I definitely remember the notice that Beryllium copper tools were to be immediately turned into Supply for replacement. -- Cheers, John B. |
#74
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grounding lightbulbs, fuses and other parts
On Wed, 23 Jul 2014 22:15:26 -0500, Martin Eastburn
wrote: On 7/23/2014 5:36 AM, Gunner Asch wrote: No knum nuts - One puts the hand in pocket when the other is in the hot zone. One can hold onto a ladder with one arm and in a pocket if you don't have belts to do it for you. Just don't get one hand on ground and the other on a hot. That is the point. Many of us HAVE to splice or hook up live wiring. Its part of the maintenance thingy. So we are very..very careful about NOT grabbing anything that is "ground"...but still work with both hands. Shrug Gunner Martin Right! One hand in the pocket.... when you are on the top of a 20 ft. ladder. And making up wire nuts...... -- "Living in the United States now is like being a Tampon. We're in a great place, just at a bad time." -- "Living in the United States now is like being a Tampon. We're in a great place, just at a bad time." |
#75
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grounding lightbulbs, fuses and other parts
Martin Eastburn fired this volley in news:N%
: IIRC BeCu tools are non-conductive. YRI (you recall incorrectly). Beryllium copper and beryllium bronze are "non-sparking alloys". They're used in explosive environments (of which I have some experience), because they will not raise a spark when struck against themselves or other metal surfaces. Beryllium/copper/tin/zinc alloys are used all the time for springs and electrical contacts in fixtures, switches, and machinery. LLoyd |
#76
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grounding lightbulbs, fuses and other parts
On Wednesday, July 23, 2014 5:56:15 PM UTC-4, amdx wrote:
"Overhead commercial lighting voltage is 277 so its less current and less dangerous," So to rephrase you said, 277 volts is less dangerous than a lower voltage. Do you still think this? No, not if your high voltage lighting branches (brown, orange or yellow phases) are from a service or from a transformer arrangement different from your low voltage receptacles branches (black, blue, and red phases). Yes, if transformed 277vac and 120vac service is all from one service (of, say two phases of 500 kcmil going into the main interface). And I don't "think" this. Its in the NEC |
#77
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grounding lightbulbs, fuses and other parts
On Thursday, July 24, 2014 11:04:39 AM UTC-4, wrote:
On Wednesday, July 23, 2014 5:56:15 PM UTC-4, amdx wrote: So to rephrase you said, 277 volts is less dangerous than a lower voltage. Do you still think this? No, not if your high voltage lighting branches (brown, orange or yellow phases) are from a service or from a transformer arrangement different from your low voltage receptacles branches (black, blue, and red phases). Yes, if transformed 277vac and 120vac service is all from one service (of, say two phases of 500 kcmil going into the main interface). And I don't "think" this. Its in the NEC Whether bad or good. Sometimes more than one service is coming into a structure. The NEC writes about that: NEC 230.3 - "An SEC cannot supply a building through another structure" |
#78
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grounding lightbulbs, fuses and other parts
On 7/24/2014 10:04 AM, wrote:
On Wednesday, July 23, 2014 5:56:15 PM UTC-4, amdx wrote: "Overhead commercial lighting voltage is 277 so its less current and less dangerous," So to rephrase you said, 277 volts is less dangerous than a lower voltage. Do you still think this? No, not if your high voltage lighting branches (brown, orange or yellow phases) are from a service or from a transformer arrangement different from your low voltage receptacles branches (black, blue, and red phases). Yes, if transformed 277vac and 120vac service is all from one service (of, say two phases of 500 kcmil going into the main interface). And I don't "think" this. Its in the NEC Which section of the NEC says Low voltage is safer than high voltage. You can quote the verbage here, " " I wonder why sidewalk lighting is low voltage? Seems like it should be 880vac for safety. Mikek --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com |
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grounding lightbulbs, fuses and other parts
amdx fired this volley in news:lqrih3$spe$1@dont-
email.me: Which section of the NEC says Low voltage is safer than high voltage. You can quote the verbage here, " " I wonder why sidewalk lighting is low voltage? Seems like it should be 880vac for safety. They don't seem to 'get' that although - yes - the 277V service might be capable of delivering less current than the 240 (but not necessarily), it can still deliver thousands of times more than necessary to fry off any appendage you want to name. Lloyd |
#80
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grounding lightbulbs, fuses and other parts
Em quinta-feira, 24 de julho de 2014 14h15min58s UTC-4, amdx escreveu:
On 7/24/2014 10:04 AM, wrote: On Wednesday, July 23, 2014 5:56:15 PM UTC-4, amdx wrote: "Overhead commercial lighting voltage is 277 so its less current and less dangerous," So to rephrase you said, 277 volts is less dangerous than a lower voltage. Do you still think this? No, not if your high voltage lighting branches (brown, orange or yellow phases) are from a service or from a transformer arrangement different from your low voltage receptacles branches (black, blue, and red phases). Yes, if transformed 277vac and 120vac service is all from one service (of, say two phases of 500 kcmil going into the main interface). And I don't "think" this. Its in the NEC Which section of the NEC says Low voltage is safer than high voltage. You can quote the verbage here, " " Mostly stuff about gfci requirements would suit. I wonder why sidewalk lighting is low voltage? 240vac 2 phase (black, blue and red) number 10 wire lighting? I never asked if it was low or high. |
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