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#1
Posted to alt.comp.hardware.pc-homebuilt,alt.engineering.electrical,sci.electronics.repair,sci.electronics.basics,alt.home.repair
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On Wed, 01 Feb 2017 17:31:50 -0000, Mr. Man-wai Chang wrote:
A small town's sudden power surge fried tech gear in hundreds of homes Full story: http://www.foxnews.com/tech/2017/01/...eds-homes.html Residents in the small Pennsylvania town of Brookville must've wondered what on earth was going on earlier this month when a sudden power surge caused electrical appliances and gizmos in up to 1,000 homes to fry, explode, or simply conk out. What may have momentarily seemed like some kind of weird supernatural happening was actually an electrical surge caused by a failed power line component, according to an AP report. Local media said that "damage ranged from residents losing a refrigerator to losing all appliances in the kitchen or losing everything in the house." Up to a quarter of the town's 4,000 residents were thought to have been affected by the incident, with many reporting fried computers, burned electrical meters, and damaged power strips. Some even spoke of fluorescent lights suddenly exploding. When the surge occurred, the high volume of calls flooding into the emergency services forced the local fire department to call for extra help from three nearby facilities. As for the local cops, the incident tripped its main office radio, causing them to miss the first emergency calls. The first they knew something was up was when they heard the fire trucks roaring through the town. "We were fortunate that nobody was hurt," Tracy Zents, the director of Jefferson County's Department of Emergency Services, told AP. You should have anything expensive in a UPS. -- A highway patrolman pulled alongside a speeding car on the freeway. Glancing at the car, he was astounded to see that the blonde behind the wheel was knitting! Realizing that she was oblivious to his flashing lights and siren, the trooper cranked down his window, turned on his bullhorn and yelled, "PULL OVER!" "NO!" the blonde yelled back, "IT'S A SCARF!" |
#2
Posted to alt.comp.hardware.pc-homebuilt,alt.engineering.electrical,sci.electronics.repair,sci.electronics.basics,alt.home.repair
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On 02/08/2017 02:46 PM, James Wilkinson Sword wrote:
On Wed, 01 Feb 2017 17:31:50 -0000, Mr. Man-wai Chang wrote: A small town's sudden power surge fried tech gear in hundreds of homes Full story: http://www.foxnews.com/tech/2017/01/...eds-homes.html Residents in the small Pennsylvania town of Brookville must've wondered what on earth was going on earlier this month when a sudden power surge caused electrical appliances and gizmos in up to 1,000 homes to fry, explode, or simply conk out. What may have momentarily seemed like some kind of weird supernatural happening was actually an electrical surge caused by a failed power line component, according to an AP report. Local media said that "damage ranged from residents losing a refrigerator to losing all appliances in the kitchen or losing everything in the house." Up to a quarter of the town's 4,000 residents were thought to have been affected by the incident, with many reporting fried computers, burned electrical meters, and damaged power strips. Some even spoke of fluorescent lights suddenly exploding. When the surge occurred, the high volume of calls flooding into the emergency services forced the local fire department to call for extra help from three nearby facilities. As for the local cops, the incident tripped its main office radio, causing them to miss the first emergency calls. The first they knew something was up was when they heard the fire trucks roaring through the town. "We were fortunate that nobody was hurt," Tracy Zents, the director of Jefferson County's Department of Emergency Services, told AP. You should have anything expensive in a UPS. Big help if the house burns down. I've heard of folks getting MOVs put in right at the meter, outside the house. In that sort of super nasty surge, they explode and isolate the house from the line. Never had the urge to do it myself, but it might be good insurance. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net |
#3
Posted to alt.comp.hardware.pc-homebuilt,alt.engineering.electrical,sci.electronics.repair,sci.electronics.basics,alt.home.repair
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On Wed, 08 Feb 2017 21:55:06 -0000, Phil Hobbs wrote:
On 02/08/2017 02:46 PM, James Wilkinson Sword wrote: On Wed, 01 Feb 2017 17:31:50 -0000, Mr. Man-wai Chang wrote: A small town's sudden power surge fried tech gear in hundreds of homes Full story: http://www.foxnews.com/tech/2017/01/...eds-homes.html Residents in the small Pennsylvania town of Brookville must've wondered what on earth was going on earlier this month when a sudden power surge caused electrical appliances and gizmos in up to 1,000 homes to fry, explode, or simply conk out. What may have momentarily seemed like some kind of weird supernatural happening was actually an electrical surge caused by a failed power line component, according to an AP report. Local media said that "damage ranged from residents losing a refrigerator to losing all appliances in the kitchen or losing everything in the house." Up to a quarter of the town's 4,000 residents were thought to have been affected by the incident, with many reporting fried computers, burned electrical meters, and damaged power strips. Some even spoke of fluorescent lights suddenly exploding. When the surge occurred, the high volume of calls flooding into the emergency services forced the local fire department to call for extra help from three nearby facilities. As for the local cops, the incident tripped its main office radio, causing them to miss the first emergency calls. The first they knew something was up was when they heard the fire trucks roaring through the town. "We were fortunate that nobody was hurt," Tracy Zents, the director of Jefferson County's Department of Emergency Services, told AP. You should have anything expensive in a UPS. Big help if the house burns down. I've heard of folks getting MOVs put in right at the meter, outside the house. In that sort of super nasty surge, they explode and isolate the house from the line. Never had the urge to do it myself, but it might be good insurance. Wouldn't a really big surge destroy the first thing it hits, i.e. the main fuse, meter, etc? -- What's the difference between PMS and Mad Cow Disease? The number of tits. |
#4
Posted to alt.comp.hardware.pc-homebuilt,alt.engineering.electrical,sci.electronics.repair,sci.electronics.basics,alt.home.repair
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On 02/08/2017 05:00 PM, James Wilkinson Sword wrote:
On Wed, 08 Feb 2017 21:55:06 -0000, Phil Hobbs wrote: On 02/08/2017 02:46 PM, James Wilkinson Sword wrote: On Wed, 01 Feb 2017 17:31:50 -0000, Mr. Man-wai Chang wrote: A small town's sudden power surge fried tech gear in hundreds of homes Full story: http://www.foxnews.com/tech/2017/01/...eds-homes.html Residents in the small Pennsylvania town of Brookville must've wondered what on earth was going on earlier this month when a sudden power surge caused electrical appliances and gizmos in up to 1,000 homes to fry, explode, or simply conk out. What may have momentarily seemed like some kind of weird supernatural happening was actually an electrical surge caused by a failed power line component, according to an AP report. Local media said that "damage ranged from residents losing a refrigerator to losing all appliances in the kitchen or losing everything in the house." Up to a quarter of the town's 4,000 residents were thought to have been affected by the incident, with many reporting fried computers, burned electrical meters, and damaged power strips. Some even spoke of fluorescent lights suddenly exploding. When the surge occurred, the high volume of calls flooding into the emergency services forced the local fire department to call for extra help from three nearby facilities. As for the local cops, the incident tripped its main office radio, causing them to miss the first emergency calls. The first they knew something was up was when they heard the fire trucks roaring through the town. "We were fortunate that nobody was hurt," Tracy Zents, the director of Jefferson County's Department of Emergency Services, told AP. You should have anything expensive in a UPS. Big help if the house burns down. I've heard of folks getting MOVs put in right at the meter, outside the house. In that sort of super nasty surge, they explode and isolate the house from the line. Never had the urge to do it myself, but it might be good insurance. Wouldn't a really big surge destroy the first thing it hits, i.e. the main fuse, meter, etc? It matters where the big arc happens, though. You don't clear a high energy 1600-4800V circuit with a domestic 240V breaker, that's for sure. The result is an _arc flash_, which you do _not_ want in your vicinity, trust me. (Youtube has a lot of examples if you doubt this.) Having a major league arc flash on a cinderblock foundation outside the house is a very different proposition from having one in a breaker box mounted to a wooden stud wall inside, for one thing, but I'm outside my experience here, so I'll happily defer to any actual power engineering types who want to chime in. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net |
#5
Posted to alt.comp.hardware.pc-homebuilt,alt.engineering.electrical,sci.electronics.repair,sci.electronics.basics,alt.home.repair
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On Wed, 08 Feb 2017 22:13:00 -0000, Phil Hobbs wrote:
On 02/08/2017 05:00 PM, James Wilkinson Sword wrote: On Wed, 08 Feb 2017 21:55:06 -0000, Phil Hobbs wrote: On 02/08/2017 02:46 PM, James Wilkinson Sword wrote: On Wed, 01 Feb 2017 17:31:50 -0000, Mr. Man-wai Chang wrote: A small town's sudden power surge fried tech gear in hundreds of homes Full story: http://www.foxnews.com/tech/2017/01/...eds-homes.html Residents in the small Pennsylvania town of Brookville must've wondered what on earth was going on earlier this month when a sudden power surge caused electrical appliances and gizmos in up to 1,000 homes to fry, explode, or simply conk out. What may have momentarily seemed like some kind of weird supernatural happening was actually an electrical surge caused by a failed power line component, according to an AP report. Local media said that "damage ranged from residents losing a refrigerator to losing all appliances in the kitchen or losing everything in the house." Up to a quarter of the town's 4,000 residents were thought to have been affected by the incident, with many reporting fried computers, burned electrical meters, and damaged power strips. Some even spoke of fluorescent lights suddenly exploding. When the surge occurred, the high volume of calls flooding into the emergency services forced the local fire department to call for extra help from three nearby facilities. As for the local cops, the incident tripped its main office radio, causing them to miss the first emergency calls. The first they knew something was up was when they heard the fire trucks roaring through the town. "We were fortunate that nobody was hurt," Tracy Zents, the director of Jefferson County's Department of Emergency Services, told AP. You should have anything expensive in a UPS. Big help if the house burns down. I've heard of folks getting MOVs put in right at the meter, outside the house. In that sort of super nasty surge, they explode and isolate the house from the line. Never had the urge to do it myself, but it might be good insurance. Wouldn't a really big surge destroy the first thing it hits, i.e. the main fuse, meter, etc? It matters where the big arc happens, though. You don't clear a high energy 1600-4800V circuit with a domestic 240V breaker, that's for sure. The result is an _arc flash_, which you do _not_ want in your vicinity, trust me. (Youtube has a lot of examples if you doubt this.) Having a major league arc flash on a cinderblock foundation outside the house is a very different proposition from having one in a breaker box mounted to a wooden stud wall inside, for one thing, but I'm outside my experience here, so I'll happily defer to any actual power engineering types who want to chime in. I can't believe it's that likely for 4800V to get onto a 240V line. Possible, but so rare it's not worth bothering to install protection. I protect against little spikes, or voltages about 30V under/over what they should be. My UPS frequently adjusts the voltage, and sometimes gives up and runs the house on batteries for 5 seconds. -- If the English language made any sense, lackadaisical would have something to do with a shortage of flowers. |
#6
Posted to alt.comp.hardware.pc-homebuilt,alt.engineering.electrical,sci.electronics.repair,sci.electronics.basics,alt.home.repair
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On 02/08/2017 05:18 PM, James Wilkinson Sword wrote:
On Wed, 08 Feb 2017 22:13:00 -0000, Phil Hobbs wrote: On 02/08/2017 05:00 PM, James Wilkinson Sword wrote: On Wed, 08 Feb 2017 21:55:06 -0000, Phil Hobbs wrote: On 02/08/2017 02:46 PM, James Wilkinson Sword wrote: On Wed, 01 Feb 2017 17:31:50 -0000, Mr. Man-wai Chang wrote: A small town's sudden power surge fried tech gear in hundreds of homes Full story: http://www.foxnews.com/tech/2017/01/...eds-homes.html Residents in the small Pennsylvania town of Brookville must've wondered what on earth was going on earlier this month when a sudden power surge caused electrical appliances and gizmos in up to 1,000 homes to fry, explode, or simply conk out. What may have momentarily seemed like some kind of weird supernatural happening was actually an electrical surge caused by a failed power line component, according to an AP report. Local media said that "damage ranged from residents losing a refrigerator to losing all appliances in the kitchen or losing everything in the house." Up to a quarter of the town's 4,000 residents were thought to have been affected by the incident, with many reporting fried computers, burned electrical meters, and damaged power strips. Some even spoke of fluorescent lights suddenly exploding. When the surge occurred, the high volume of calls flooding into the emergency services forced the local fire department to call for extra help from three nearby facilities. As for the local cops, the incident tripped its main office radio, causing them to miss the first emergency calls. The first they knew something was up was when they heard the fire trucks roaring through the town. "We were fortunate that nobody was hurt," Tracy Zents, the director of Jefferson County's Department of Emergency Services, told AP. You should have anything expensive in a UPS. Big help if the house burns down. I've heard of folks getting MOVs put in right at the meter, outside the house. In that sort of super nasty surge, they explode and isolate the house from the line. Never had the urge to do it myself, but it might be good insurance. Wouldn't a really big surge destroy the first thing it hits, i.e. the main fuse, meter, etc? It matters where the big arc happens, though. You don't clear a high energy 1600-4800V circuit with a domestic 240V breaker, that's for sure. The result is an _arc flash_, which you do _not_ want in your vicinity, trust me. (Youtube has a lot of examples if you doubt this.) Having a major league arc flash on a cinderblock foundation outside the house is a very different proposition from having one in a breaker box mounted to a wooden stud wall inside, for one thing, but I'm outside my experience here, so I'll happily defer to any actual power engineering types who want to chime in. I can't believe it's that likely for 4800V to get onto a 240V line. Possible, but so rare it's not worth bothering to install protection. I protect against little spikes, or voltages about 30V under/over what they should be. My UPS frequently adjusts the voltage, and sometimes gives up and runs the house on batteries for 5 seconds. Well, I bought my house in 1990, and still haven't done that, so I guess you can say I agree. Cheers Phil Hobbs |
#7
Posted to alt.comp.hardware.pc-homebuilt,alt.engineering.electrical,sci.electronics.repair,sci.electronics.basics,alt.home.repair
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On Wed, 08 Feb 2017 22:22:27 -0000, Phil Hobbs wrote:
On 02/08/2017 05:18 PM, James Wilkinson Sword wrote: On Wed, 08 Feb 2017 22:13:00 -0000, Phil Hobbs wrote: On 02/08/2017 05:00 PM, James Wilkinson Sword wrote: On Wed, 08 Feb 2017 21:55:06 -0000, Phil Hobbs wrote: On 02/08/2017 02:46 PM, James Wilkinson Sword wrote: On Wed, 01 Feb 2017 17:31:50 -0000, Mr. Man-wai Chang wrote: A small town's sudden power surge fried tech gear in hundreds of homes Full story: http://www.foxnews.com/tech/2017/01/...eds-homes.html Residents in the small Pennsylvania town of Brookville must've wondered what on earth was going on earlier this month when a sudden power surge caused electrical appliances and gizmos in up to 1,000 homes to fry, explode, or simply conk out. What may have momentarily seemed like some kind of weird supernatural happening was actually an electrical surge caused by a failed power line component, according to an AP report. Local media said that "damage ranged from residents losing a refrigerator to losing all appliances in the kitchen or losing everything in the house." Up to a quarter of the town's 4,000 residents were thought to have been affected by the incident, with many reporting fried computers, burned electrical meters, and damaged power strips. Some even spoke of fluorescent lights suddenly exploding. When the surge occurred, the high volume of calls flooding into the emergency services forced the local fire department to call for extra help from three nearby facilities. As for the local cops, the incident tripped its main office radio, causing them to miss the first emergency calls. The first they knew something was up was when they heard the fire trucks roaring through the town. "We were fortunate that nobody was hurt," Tracy Zents, the director of Jefferson County's Department of Emergency Services, told AP. You should have anything expensive in a UPS. Big help if the house burns down. I've heard of folks getting MOVs put in right at the meter, outside the house. In that sort of super nasty surge, they explode and isolate the house from the line. Never had the urge to do it myself, but it might be good insurance. Wouldn't a really big surge destroy the first thing it hits, i.e. the main fuse, meter, etc? It matters where the big arc happens, though. You don't clear a high energy 1600-4800V circuit with a domestic 240V breaker, that's for sure. The result is an _arc flash_, which you do _not_ want in your vicinity, trust me. (Youtube has a lot of examples if you doubt this.) Having a major league arc flash on a cinderblock foundation outside the house is a very different proposition from having one in a breaker box mounted to a wooden stud wall inside, for one thing, but I'm outside my experience here, so I'll happily defer to any actual power engineering types who want to chime in. I can't believe it's that likely for 4800V to get onto a 240V line. Possible, but so rare it's not worth bothering to install protection. I protect against little spikes, or voltages about 30V under/over what they should be. My UPS frequently adjusts the voltage, and sometimes gives up and runs the house on batteries for 5 seconds. Well, I bought my house in 1990, and still haven't done that, so I guess you can say I agree. I got my house in 2000. I got a UPS for the computer to keep it from crashing and corrupting the hard disk with 5 second powercuts. But when I got some LED lighting and it kept failing, I paid more attention to the UPS and noticed it was frequently reporting overvoltage. Connecting all the house lighting to the UPS prevented the LEDs from failing so often. The overvoltage takes the 230V up to about 256V, but apparently this is within specs, so the power company refuses to fix it. It started happening when they renewed the street's transformer (substation). They did send an electrician round, but he said there was nothing he could do, although he did comment that the guy responsible for voltage regulation in my area wasn't as fussy as he was. He claimed he liked to set things to precisely 230V, and the new guy just let it go if it was within the 10% legally allowed. I kept a close eye on the voltage, and it never gets below (or even down to) 230V, so clearly it's not averaging the correct value, and should be adjusted more accurately, but the power company doesn't give a ****. |
#8
Posted to alt.home.repair
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On Wednesday, February 8, 2017 at 5:18:18 PM UTC-5, James Wilkinson Sword wrote:
I can't believe it's that likely for 4800V to get onto a 240V line. Possible, but so rare it's not worth bothering to install protection. How frequently it happens, can't say, but all it takes is a car hitting a pole along the road, taking it down, with one of the primary wires dropping onto the 240V lines that serve homes. I protect against little spikes, or voltages about 30V under/over what they should be. Which is something virtually all modern electronics and components don't need to be protected against. Power supplies will take that range of over voltage and they all have MOVs to protect against short spikes that are hundreds of volts or more. |
#9
Posted to alt.home.repair
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On Wed, 08 Feb 2017 23:14:02 -0000, trader_4 wrote:
On Wednesday, February 8, 2017 at 5:18:18 PM UTC-5, James Wilkinson Sword wrote: I can't believe it's that likely for 4800V to get onto a 240V line. Possible, but so rare it's not worth bothering to install protection. How frequently it happens, can't say, but all it takes is a car hitting a pole along the road, taking it down, with one of the primary wires dropping onto the 240V lines that serve homes. In the UK I cannot think of where there would be an exposed HV wire and a 240V wire in close proximity. Usually the HV wires are underground and insulated up to the transformer, then the 240V is either also underground and insulated, or with older houses where the wires were inserted above ground into the roof, they are the only ones bare. I protect against little spikes, or voltages about 30V under/over what they should be. Which is something virtually all modern electronics and components don't need to be protected against. Power supplies will take that range of over voltage and they all have MOVs to protect against short spikes that are hundreds of volts or more. Not LED lightbulbs, they're too cheap to have that protection. And my computer is not protected against 5 second outages. The system shuts off and corrupts the hard disk. -- Two fish are in a tank. One says to the other, "I'll man the guns, you drive". |
#10
Posted to alt.home.repair
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On Wednesday, February 8, 2017 at 6:20:05 PM UTC-5, James Wilkinson Sword wrote:
On Wed, 08 Feb 2017 23:14:02 -0000, trader_4 wrote: On Wednesday, February 8, 2017 at 5:18:18 PM UTC-5, James Wilkinson Sword wrote: I can't believe it's that likely for 4800V to get onto a 240V line. Possible, but so rare it's not worth bothering to install protection. How frequently it happens, can't say, but all it takes is a car hitting a pole along the road, taking it down, with one of the primary wires dropping onto the 240V lines that serve homes. In the UK I cannot think of where there would be an exposed HV wire and a 240V wire in close proximity. Usually the HV wires are underground and insulated up to the transformer, then the 240V is either also underground and insulated, or with older houses where the wires were inserted above ground into the roof, they are the only ones bare. If you really have underground distribution lines running around out in the country, it could explain why you're paying so damn much for electric. Here the common approach in rural areas is to have poles with the primaries at the top, then a pole mounted transformer that drops it down to 240V. IDK what all the primary voltages are, but think typical is probably ~10K. Underground is in cities, towns, more developed subdivisions with newer homes. I protect against little spikes, or voltages about 30V under/over what they should be. Which is something virtually all modern electronics and components don't need to be protected against. Power supplies will take that range of over voltage and they all have MOVs to protect against short spikes that are hundreds of volts or more. Not LED lightbulbs, they're too cheap to have that protection. And my computer is not protected against 5 second outages. The system shuts off and corrupts the hard disk. You said "spikes" of 30 volts. A spike is not a 5 sec outage. A PC would never even notice a 30V spike. And while a surge protector can protect against spikes of thousands of volts, a surge protector is not going to guard against a 5 sec power outage. |
#11
Posted to alt.home.repair
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On Wed, 08 Feb 2017 23:43:54 -0000, trader_4 wrote:
On Wednesday, February 8, 2017 at 6:20:05 PM UTC-5, James Wilkinson Sword wrote: On Wed, 08 Feb 2017 23:14:02 -0000, trader_4 wrote: On Wednesday, February 8, 2017 at 5:18:18 PM UTC-5, James Wilkinson Sword wrote: I can't believe it's that likely for 4800V to get onto a 240V line. Possible, but so rare it's not worth bothering to install protection. How frequently it happens, can't say, but all it takes is a car hitting a pole along the road, taking it down, with one of the primary wires dropping onto the 240V lines that serve homes. In the UK I cannot think of where there would be an exposed HV wire and a 240V wire in close proximity. Usually the HV wires are underground and insulated up to the transformer, then the 240V is either also underground and insulated, or with older houses where the wires were inserted above ground into the roof, they are the only ones bare. If you really have underground distribution lines running around out in the country, it could explain why you're paying so damn much for electric. Here the common approach in rural areas is to have poles with the primaries at the top, then a pole mounted transformer that drops it down to 240V. IDK what all the primary voltages are, but think typical is probably ~10K. Underground is in cities, towns, more developed subdivisions with newer homes. I'm not so sure underground is more expensive. It tends to stay there and not get blown or knocked down. I used to live in a remote area where the primaries were above ground. They often got blown down or knocked over by bulls in a field. Primary here is 11,000V. I protect against little spikes, or voltages about 30V under/over what they should be. Which is something virtually all modern electronics and components don't need to be protected against. Power supplies will take that range of over voltage and they all have MOVs to protect against short spikes that are hundreds of volts or more. Not LED lightbulbs, they're too cheap to have that protection. And my computer is not protected against 5 second outages. The system shuts off and corrupts the hard disk. You said "spikes" of 30 volts. No, I said spikes AND voltages up to 30 over. I often get a constant voltage far above the nominal 230V. A spike is not a 5 sec outage. A PC would never even notice a 30V spike. And while a surge protector can protect against spikes of thousands of volts, a surge protector is not going to guard against a 5 sec power outage. My UPS does, it has batteries which will last half an hour. If that half hour approaches, it instructs the PC to shut down gracefully. -- god said: "The Divergence of the B Field = 0 The Curl of the E Field + the partial time derivative of the B field = 0 The Divergence of the D field = the charge density The Curl of the H field - the partial time derivative of the D field = the current density" and there was light, and he saw that it was good and of constant speed. |
#12
Posted to alt.comp.hardware.pc-homebuilt,alt.engineering.electrical,sci.electronics.repair,sci.electronics.basics,alt.home.repair
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[FoxNews]A small town's sudden power surge fried tech gear in hundreds of homes
On Wed, 8 Feb 2017 17:22:27 -0500, Phil Hobbs
wrote: On 02/08/2017 05:18 PM, James Wilkinson Sword wrote: On Wed, 08 Feb 2017 22:13:00 -0000, Phil Hobbs wrote: On 02/08/2017 05:00 PM, James Wilkinson Sword wrote: On Wed, 08 Feb 2017 21:55:06 -0000, Phil Hobbs wrote: On 02/08/2017 02:46 PM, James Wilkinson Sword wrote: On Wed, 01 Feb 2017 17:31:50 -0000, Mr. Man-wai Chang wrote: A small town's sudden power surge fried tech gear in hundreds of homes Full story: http://www.foxnews.com/tech/2017/01/...eds-homes.html Residents in the small Pennsylvania town of Brookville must've wondered what on earth was going on earlier this month when a sudden power surge caused electrical appliances and gizmos in up to 1,000 homes to fry, explode, or simply conk out. What may have momentarily seemed like some kind of weird supernatural happening was actually an electrical surge caused by a failed power line component, according to an AP report. Local media said that "damage ranged from residents losing a refrigerator to losing all appliances in the kitchen or losing everything in the house." Up to a quarter of the town's 4,000 residents were thought to have been affected by the incident, with many reporting fried computers, burned electrical meters, and damaged power strips. Some even spoke of fluorescent lights suddenly exploding. When the surge occurred, the high volume of calls flooding into the emergency services forced the local fire department to call for extra help from three nearby facilities. As for the local cops, the incident tripped its main office radio, causing them to miss the first emergency calls. The first they knew something was up was when they heard the fire trucks roaring through the town. "We were fortunate that nobody was hurt," Tracy Zents, the director of Jefferson County's Department of Emergency Services, told AP. You should have anything expensive in a UPS. Big help if the house burns down. I've heard of folks getting MOVs put in right at the meter, outside the house. In that sort of super nasty surge, they explode and isolate the house from the line. Never had the urge to do it myself, but it might be good insurance. Wouldn't a really big surge destroy the first thing it hits, i.e. the main fuse, meter, etc? It matters where the big arc happens, though. You don't clear a high energy 1600-4800V circuit with a domestic 240V breaker, that's for sure. The result is an _arc flash_, which you do _not_ want in your vicinity, trust me. (Youtube has a lot of examples if you doubt this.) Having a major league arc flash on a cinderblock foundation outside the house is a very different proposition from having one in a breaker box mounted to a wooden stud wall inside, for one thing, but I'm outside my experience here, so I'll happily defer to any actual power engineering types who want to chime in. I can't believe it's that likely for 4800V to get onto a 240V line. Possible, but so rare it's not worth bothering to install protection. I protect against little spikes, or voltages about 30V under/over what they should be. My UPS frequently adjusts the voltage, and sometimes gives up and runs the house on batteries for 5 seconds. Well, I bought my house in 1990, and still haven't done that, so I guess you can say I agree. Cheers Phil Hobbs A truck hit a padmounted transformer about 100 ft from my dad's house, shorting the primary to the secondaty momentarily before tripping the fuse. It blew the fuse in his then- new TV and blew one or two bulbe - but destroyed half the appliances in the house next door. I fixed the TV - Dad replaced the bulbs, and Waterloo North Hydro's and the truck driver's insurance replaced the neighbours appliances. The transformer made a BIG BANG when the circuit protector blew. |
#13
Posted to alt.comp.hardware.pc-homebuilt,alt.engineering.electrical,sci.electronics.repair,sci.electronics.basics,alt.home.repair
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On Thu, 09 Feb 2017 00:17:25 -0000, wrote:
On Wed, 8 Feb 2017 17:22:27 -0500, Phil Hobbs wrote: On 02/08/2017 05:18 PM, James Wilkinson Sword wrote: On Wed, 08 Feb 2017 22:13:00 -0000, Phil Hobbs wrote: On 02/08/2017 05:00 PM, James Wilkinson Sword wrote: On Wed, 08 Feb 2017 21:55:06 -0000, Phil Hobbs wrote: On 02/08/2017 02:46 PM, James Wilkinson Sword wrote: On Wed, 01 Feb 2017 17:31:50 -0000, Mr. Man-wai Chang wrote: A small town's sudden power surge fried tech gear in hundreds of homes Full story: http://www.foxnews.com/tech/2017/01/...eds-homes.html Residents in the small Pennsylvania town of Brookville must've wondered what on earth was going on earlier this month when a sudden power surge caused electrical appliances and gizmos in up to 1,000 homes to fry, explode, or simply conk out. What may have momentarily seemed like some kind of weird supernatural happening was actually an electrical surge caused by a failed power line component, according to an AP report. Local media said that "damage ranged from residents losing a refrigerator to losing all appliances in the kitchen or losing everything in the house." Up to a quarter of the town's 4,000 residents were thought to have been affected by the incident, with many reporting fried computers, burned electrical meters, and damaged power strips. Some even spoke of fluorescent lights suddenly exploding. When the surge occurred, the high volume of calls flooding into the emergency services forced the local fire department to call for extra help from three nearby facilities. As for the local cops, the incident tripped its main office radio, causing them to miss the first emergency calls. The first they knew something was up was when they heard the fire trucks roaring through the town. "We were fortunate that nobody was hurt," Tracy Zents, the director of Jefferson County's Department of Emergency Services, told AP. You should have anything expensive in a UPS. Big help if the house burns down. I've heard of folks getting MOVs put in right at the meter, outside the house. In that sort of super nasty surge, they explode and isolate the house from the line. Never had the urge to do it myself, but it might be good insurance. Wouldn't a really big surge destroy the first thing it hits, i.e. the main fuse, meter, etc? It matters where the big arc happens, though. You don't clear a high energy 1600-4800V circuit with a domestic 240V breaker, that's for sure. The result is an _arc flash_, which you do _not_ want in your vicinity, trust me. (Youtube has a lot of examples if you doubt this.) Having a major league arc flash on a cinderblock foundation outside the house is a very different proposition from having one in a breaker box mounted to a wooden stud wall inside, for one thing, but I'm outside my experience here, so I'll happily defer to any actual power engineering types who want to chime in. I can't believe it's that likely for 4800V to get onto a 240V line. Possible, but so rare it's not worth bothering to install protection. I protect against little spikes, or voltages about 30V under/over what they should be. My UPS frequently adjusts the voltage, and sometimes gives up and runs the house on batteries for 5 seconds. Well, I bought my house in 1990, and still haven't done that, so I guess you can say I agree. Cheers Phil Hobbs A truck hit a padmounted transformer about 100 ft from my dad's house, shorting the primary to the secondaty momentarily before tripping the fuse. It blew the fuse in his then- new TV and blew one or two bulbe - but destroyed half the appliances in the house next door. I fixed the TV - Dad replaced the bulbs, and Waterloo North Hydro's and the truck driver's insurance replaced the neighbours appliances. The transformer made a BIG BANG when the circuit protector blew. Pity it didn't electrocute the truck driver. -- During the weekly Lamaze class, the instructor emphasized the importance of exercise, hinting strongly that husbands need to get out and start walking with their wives. From the back of the room one expectant father inquired, "Would it be okay if she carries a bag of golf clubs while she walks?" |
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On Wednesday, February 8, 2017 at 6:51:01 PM UTC-5, James Wilkinson Sword
I'm not so sure underground is more expensive. That's OK, the power companies know that it is. It tends to stay there and not get blown or knocked down. I used to live in a remote area where the primaries were above ground. They often got blown down or knocked over by bulls in a field. If power line primaries are getting knocked over by bulls, obviously you're doing something very wrong over there. Primary here is 11,000V. I protect against little spikes, or voltages about 30V under/over what they should be. Which is something virtually all modern electronics and components don't need to be protected against. Power supplies will take that range of over voltage and they all have MOVs to protect against short spikes that are hundreds of volts or more. Not LED lightbulbs, they're too cheap to have that protection. And my computer is not protected against 5 second outages. The system shuts off and corrupts the hard disk. You said "spikes" of 30 volts. No, I said spikes AND voltages up to 30 over. I often get a constant voltage far above the nominal 230V. That's rare here, at least where I've lived. A spike is not a 5 sec outage. A PC would never even notice a 30V spike. And while a surge protector can protect against spikes of thousands of volts, a surge protector is not going to guard against a 5 sec power outage. My UPS does, it has batteries which will last half an hour. If that half hour approaches, it instructs the PC to shut down gracefully. -- god said: "The Divergence of the B Field = 0 The Curl of the E Field + the partial time derivative of the B field = 0 The Divergence of the D field = the charge density The Curl of the H field - the partial time derivative of the D field = the current density" and there was light, and he saw that it was good and of constant speed. Maxwell was one of the greats from the UK that forever changed the world. |
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On Thu, 09 Feb 2017 00:47:15 -0000, trader_4 wrote:
On Wednesday, February 8, 2017 at 6:51:01 PM UTC-5, James Wilkinson Sword I'm not so sure underground is more expensive. That's OK, the power companies know that it is. Well they must do it for a reason here. It tends to stay there and not get blown or knocked down. I used to live in a remote area where the primaries were above ground. They often got blown down or knocked over by bulls in a field. If power line primaries are getting knocked over by bulls, obviously you're doing something very wrong over there. No taming the bulls? Primary here is 11,000V. I protect against little spikes, or voltages about 30V under/over what they should be. Which is something virtually all modern electronics and components don't need to be protected against. Power supplies will take that range of over voltage and they all have MOVs to protect against short spikes that are hundreds of volts or more. Not LED lightbulbs, they're too cheap to have that protection. And my computer is not protected against 5 second outages. The system shuts off and corrupts the hard disk. You said "spikes" of 30 volts. No, I said spikes AND voltages up to 30 over. I often get a constant voltage far above the nominal 230V. That's rare here, at least where I've lived. It was here too. The previous transformer was 240V +/- 1. The new one is anything from 245V to 255V. It's supposed to be 230V. A spike is not a 5 sec outage. A PC would never even notice a 30V spike. And while a surge protector can protect against spikes of thousands of volts, a surge protector is not going to guard against a 5 sec power outage. My UPS does, it has batteries which will last half an hour. If that half hour approaches, it instructs the PC to shut down gracefully. -- god said: "The Divergence of the B Field = 0 The Curl of the E Field + the partial time derivative of the B field = 0 The Divergence of the D field = the charge density The Curl of the H field - the partial time derivative of the D field = the current density" and there was light, and he saw that it was good and of constant speed. Maxwell was one of the greats from the UK that forever changed the world. Agreed. -- Say it with flowers - send her a triffid. |
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On Wednesday, February 8, 2017 at 5:18:18 PM UTC-5, James Wilkinson Sword wrote:
I can't believe it's that likely for 4800V to get onto a 240V line. Possible, but so rare it's not worth bothering to install protection. I protect against little spikes, or voltages about 30V under/over what they should be. 30 volts and higher is already solved inside each appliance. Why would anyone spend money to protect from something that does not even cause damage? That is already made irrelevant by what already must exist inside every appliance? A 33,000 volt wire fell upon the local distribution. Even electric meters were blown 30 feet from their pans. Many suffered appliance damage and destroyed protectors. At least one suffered damaged circuit breakers. My friend knows someone who knows this stuff. So he had a 'whole house' protector. His electric meter was also damaged. But nothing else. Even the 'whole house' protector was not damaged. In part, because it was properly earthed. Transients created by lightning, linemen errors, tree rodents, stray cars, and insulator failures are rare. So we properly earth a 'whole house' solution for about $1 per protected appliance. Then such threats do not cause hardware damage - even to that 'whole house' protector. |
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On Thu, 09 Feb 2017 14:53:02 -0000, westom wrote:
On Wednesday, February 8, 2017 at 5:18:18 PM UTC-5, James Wilkinson Sword wrote: I can't believe it's that likely for 4800V to get onto a 240V line. Possible, but so rare it's not worth bothering to install protection. I protect against little spikes, or voltages about 30V under/over what they should be. 30 volts and higher is already solved inside each appliance. Why would anyone spend money to protect from something that does not even cause damage? That is already made irrelevant by what already must exist inside every appliance? Might do in quality appliances, but not cheap ones, or LED lightbulbs. A 33,000 volt wire fell upon the local distribution. Even electric meters were blown 30 feet from their pans. Many suffered appliance damage and destroyed protectors. At least one suffered damaged circuit breakers. I'm glad our HV lines aren't hung up in the air! My friend knows someone who knows this stuff. So he had a 'whole house' protector. His electric meter was also damaged. But nothing else. Even the 'whole house' protector was not damaged. In part, because it was properly earthed. Transients created by lightning, linemen errors, tree rodents, stray cars, and insulator failures are rare. So we properly earth a 'whole house' solution for about $1 per protected appliance. Then such threats do not cause hardware damage - even to that 'whole house' protector. -- A man comes out of a shopping mall to find that the side of his parked car is rammed in. Seeing a note under the windshield, he read it. On the paper is written: "As I'm writing this, about a dozen people are watching me. They think I'm giving you my name, phone number, and insurance company. But I'm not." |
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On Thu, 09 Feb 2017 14:23:17 -0000, Mark F wrote:
On Wed, 08 Feb 2017 19:17:25 -0500, wrote in part: http://www.foxnews.com/tech/2017/01/...eds-homes.html Residents in the small Pennsylvania town of Brookville must've wondered what on earth was going on earlier this month when a sudden power surge caused electrical appliances and gizmos in up to 1,000 homes to fry, explode, or simply conk out. At least 5 different times in 15 years my house has had 1 or 2 devices die immediately when there was lighting around or someone ran into a power pole. At least 4 times 1 or more devices failed within a couple of weeks. I'd say all appliances should be replaced by the power company if any in the house failed, or at least anything that fails in the next 5 years should be replaced when it fails. Also: A UPS is more likely to get fried itself in the cases like in the above report. House MOV seems like the only hope to protect from these events. I just don't have the severe things like above. I'm just catering for loss of power for a few seconds, and for the voltage being out a bit. -- Went to the pub with my girlfriend last night. Locals were shouting "paedophile!" and other names at me, just because my girlfriend is 21 and I'm 50. It completely spoilt our 10th anniversary. |
#20
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On Thursday, February 9, 2017 at 10:15:52 AM UTC-5, James Wilkinson Sword wrote:
On Thu, 09 Feb 2017 14:53:02 -0000, westom wrote: On Wednesday, February 8, 2017 at 5:18:18 PM UTC-5, James Wilkinson Sword wrote: I can't believe it's that likely for 4800V to get onto a 240V line. Possible, but so rare it's not worth bothering to install protection. I protect against little spikes, or voltages about 30V under/over what they should be. 30 volts and higher is already solved inside each appliance. Why would anyone spend money to protect from something that does not even cause damage? That is already made irrelevant by what already must exist inside every appliance? Might do in quality appliances, but not cheap ones, or LED lightbulbs. Even cheap appliances have MOVs for small surges and will tolerate the ~ 12% overvoltages you're talking about. I don't have much experience with LEDs, but see no reason why they can't tolerate your 12% over voltage for seconds. If all these things were as sensitive as you claim, we'd see a lot of failures. I sure don't. A 33,000 volt wire fell upon the local distribution. Even electric meters were blown 30 feet from their pans. Many suffered appliance damage and destroyed protectors. At least one suffered damaged circuit breakers. I'm glad our HV lines aren't hung up in the air! Apparently the power company is lying then. http://www2.nationalgrid.com/uk/serv...verhead-lines/ Are you blind? |
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[FoxNews]A small town's sudden power surge fried tech gear in hundreds of homes
On Thu, 09 Feb 2017 09:23:17 -0500, Mark F
wrote: On Wed, 08 Feb 2017 19:17:25 -0500, wrote in part: http://www.foxnews.com/tech/2017/01/...eds-homes.html Residents in the small Pennsylvania town of Brookville must've wondered what on earth was going on earlier this month when a sudden power surge caused electrical appliances and gizmos in up to 1,000 homes to fry, explode, or simply conk out. At least 5 different times in 15 years my house has had 1 or 2 devices die immediately when there was lighting around or someone ran into a power pole. At least 4 times 1 or more devices failed within a couple of weeks. I'd say all appliances should be replaced by the power company if any in the house failed, or at least anything that fails in the next 5 years should be replaced when it fails. Also: A UPS is more likely to get fried itself in the cases like in the above report. House MOV seems like the only hope to protect from these events. I installed a whole house surge protector in my new panel last year. I figured it was cheap insurance. |
#22
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On Wednesday, February 8, 2017 at 5:18:18 PM UTC-5, James Wilkinson Sword wrote:
On Wed, 08 Feb 2017 22:13:00 -0000, Phil Hobbs wrote: On 02/08/2017 05:00 PM, James Wilkinson Sword wrote: On Wed, 08 Feb 2017 21:55:06 -0000, Phil Hobbs wrote: On 02/08/2017 02:46 PM, James Wilkinson Sword wrote: On Wed, 01 Feb 2017 17:31:50 -0000, Mr. Man-wai Chang wrote: A small town's sudden power surge fried tech gear in hundreds of homes Full story: http://www.foxnews.com/tech/2017/01/...eds-homes.html Residents in the small Pennsylvania town of Brookville must've wondered what on earth was going on earlier this month when a sudden power surge caused electrical appliances and gizmos in up to 1,000 homes to fry, explode, or simply conk out. What may have momentarily seemed like some kind of weird supernatural happening was actually an electrical surge caused by a failed power line component, according to an AP report. Local media said that "damage ranged from residents losing a refrigerator to losing all appliances in the kitchen or losing everything in the house." Up to a quarter of the town's 4,000 residents were thought to have been affected by the incident, with many reporting fried computers, burned electrical meters, and damaged power strips. Some even spoke of fluorescent lights suddenly exploding. When the surge occurred, the high volume of calls flooding into the emergency services forced the local fire department to call for extra help from three nearby facilities. As for the local cops, the incident tripped its main office radio, causing them to miss the first emergency calls. The first they knew something was up was when they heard the fire trucks roaring through the town. "We were fortunate that nobody was hurt," Tracy Zents, the director of Jefferson County's Department of Emergency Services, told AP. You should have anything expensive in a UPS. Big help if the house burns down. I've heard of folks getting MOVs put in right at the meter, outside the house. In that sort of super nasty surge, they explode and isolate the house from the line. Never had the urge to do it myself, but it might be good insurance. Wouldn't a really big surge destroy the first thing it hits, i.e. the main fuse, meter, etc? It matters where the big arc happens, though. You don't clear a high energy 1600-4800V circuit with a domestic 240V breaker, that's for sure.. The result is an _arc flash_, which you do _not_ want in your vicinity, trust me. (Youtube has a lot of examples if you doubt this.) Having a major league arc flash on a cinderblock foundation outside the house is a very different proposition from having one in a breaker box mounted to a wooden stud wall inside, for one thing, but I'm outside my experience here, so I'll happily defer to any actual power engineering types who want to chime in. I can't believe it's that likely for 4800V to get onto a 240V line. Possible, but so rare it's not worth bothering to install protection. I protect against little spikes, or voltages about 30V under/over what they should be. My UPS frequently adjusts the voltage, and sometimes gives up and runs the house on batteries for 5 seconds. -- If the English language made any sense, lackadaisical would have something to do with a shortage of flowers. That exact scenario happened to me in the last house I owned. I lost a few minor things that I repaired myself, neighbor one street over wasn't so lucky, he lost a crapton of electronics. I did have layered protection, I had a whole house TVSS at the breaker box plus local surge protectors or UPS units at critical electronics. |
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On Thu, 09 Feb 2017 17:38:16 -0000, trader_4 wrote:
On Thursday, February 9, 2017 at 10:15:52 AM UTC-5, James Wilkinson Sword wrote: On Thu, 09 Feb 2017 14:53:02 -0000, westom wrote: On Wednesday, February 8, 2017 at 5:18:18 PM UTC-5, James Wilkinson Sword wrote: I can't believe it's that likely for 4800V to get onto a 240V line. Possible, but so rare it's not worth bothering to install protection. I protect against little spikes, or voltages about 30V under/over what they should be. 30 volts and higher is already solved inside each appliance. Why would anyone spend money to protect from something that does not even cause damage? That is already made irrelevant by what already must exist inside every appliance? Might do in quality appliances, but not cheap ones, or LED lightbulbs. Even cheap appliances have MOVs for small surges and will tolerate the ~ 12% overvoltages you're talking about. I don't have much experience with LEDs, but see no reason why they can't tolerate your 12% over voltage for seconds. More like about 3 hours. If all these things were as sensitive as you claim, we'd see a lot of failures. I sure don't. Do you have 3 hours of 30 volts over? Do you have cheap LED lightbulbs? A 33,000 volt wire fell upon the local distribution. Even electric meters were blown 30 feet from their pans. Many suffered appliance damage and destroyed protectors. At least one suffered damaged circuit breakers. I'm glad our HV lines aren't hung up in the air! Apparently the power company is lying then. http://www2.nationalgrid.com/uk/serv...verhead-lines/ Are you blind? Most overhead lines here are the big 330kV pylons. The 11kV you were referring to doesn't tend to run down the streets alongside the 240V. -- BREAKFAST.SYS halted... Cereal port not responding. |
#24
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On Thu, 09 Feb 2017 18:46:00 -0000, N8N wrote:
On Wednesday, February 8, 2017 at 5:18:18 PM UTC-5, James Wilkinson Sword wrote: On Wed, 08 Feb 2017 22:13:00 -0000, Phil Hobbs wrote: On 02/08/2017 05:00 PM, James Wilkinson Sword wrote: On Wed, 08 Feb 2017 21:55:06 -0000, Phil Hobbs wrote: On 02/08/2017 02:46 PM, James Wilkinson Sword wrote: On Wed, 01 Feb 2017 17:31:50 -0000, Mr. Man-wai Chang wrote: A small town's sudden power surge fried tech gear in hundreds of homes Full story: http://www.foxnews.com/tech/2017/01/...eds-homes.html Residents in the small Pennsylvania town of Brookville must've wondered what on earth was going on earlier this month when a sudden power surge caused electrical appliances and gizmos in up to 1,000 homes to fry, explode, or simply conk out. What may have momentarily seemed like some kind of weird supernatural happening was actually an electrical surge caused by a failed power line component, according to an AP report. Local media said that "damage ranged from residents losing a refrigerator to losing all appliances in the kitchen or losing everything in the house." Up to a quarter of the town's 4,000 residents were thought to have been affected by the incident, with many reporting fried computers, burned electrical meters, and damaged power strips. Some even spoke of fluorescent lights suddenly exploding. When the surge occurred, the high volume of calls flooding into the emergency services forced the local fire department to call for extra help from three nearby facilities. As for the local cops, the incident tripped its main office radio, causing them to miss the first emergency calls. The first they knew something was up was when they heard the fire trucks roaring through the town. "We were fortunate that nobody was hurt," Tracy Zents, the director of Jefferson County's Department of Emergency Services, told AP. You should have anything expensive in a UPS. Big help if the house burns down. I've heard of folks getting MOVs put in right at the meter, outside the house. In that sort of super nasty surge, they explode and isolate the house from the line. Never had the urge to do it myself, but it might be good insurance. Wouldn't a really big surge destroy the first thing it hits, i.e. the main fuse, meter, etc? It matters where the big arc happens, though. You don't clear a high energy 1600-4800V circuit with a domestic 240V breaker, that's for sure. The result is an _arc flash_, which you do _not_ want in your vicinity, trust me. (Youtube has a lot of examples if you doubt this.) Having a major league arc flash on a cinderblock foundation outside the house is a very different proposition from having one in a breaker box mounted to a wooden stud wall inside, for one thing, but I'm outside my experience here, so I'll happily defer to any actual power engineering types who want to chime in. I can't believe it's that likely for 4800V to get onto a 240V line. Possible, but so rare it's not worth bothering to install protection. I protect against little spikes, or voltages about 30V under/over what they should be. My UPS frequently adjusts the voltage, and sometimes gives up and runs the house on batteries for 5 seconds. -- If the English language made any sense, lackadaisical would have something to do with a shortage of flowers. That exact scenario happened to me in the last house I owned. I lost a few minor things that I repaired myself, neighbor one street over wasn't so lucky, he lost a crapton of electronics. I did have layered protection, I had a whole house TVSS at the breaker box plus local surge protectors or UPS units at critical electronics. This seems to be common in the US but not the UK.... -- "If you have voted after you are dead, there is a good strong possibility that you did something illegal." -- Kevin Shwedo, California DMV director |
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On Thursday, February 9, 2017 at 2:35:23 PM UTC-5, James Wilkinson Sword wrote:
On Thu, 09 Feb 2017 17:38:16 -0000, trader_4 wrote: On Thursday, February 9, 2017 at 10:15:52 AM UTC-5, James Wilkinson Sword wrote: On Thu, 09 Feb 2017 14:53:02 -0000, westom wrote: On Wednesday, February 8, 2017 at 5:18:18 PM UTC-5, James Wilkinson Sword wrote: I can't believe it's that likely for 4800V to get onto a 240V line. Possible, but so rare it's not worth bothering to install protection. I protect against little spikes, or voltages about 30V under/over what they should be. 30 volts and higher is already solved inside each appliance. Why would anyone spend money to protect from something that does not even cause damage? That is already made irrelevant by what already must exist inside every appliance? Might do in quality appliances, but not cheap ones, or LED lightbulbs. Even cheap appliances have MOVs for small surges and will tolerate the ~ 12% overvoltages you're talking about. I don't have much experience with LEDs, but see no reason why they can't tolerate your 12% over voltage for seconds. More like about 3 hours. What kind of backward country are you living in over there? If I had over voltages of 30 volts happening for even seconds at a time, the power company would come out, find out what's wrong, and fix it. If all these things were as sensitive as you claim, we'd see a lot of failures. I sure don't. Do you have 3 hours of 30 volts over? Since we are at 120V, that would be 15 volts over, and no, I don't have 15 or 30 volts over. WTF is wrong over there? Do you have cheap LED lightbulbs? I have some 5" retrofits for recessed lights that I paid $10 a piece for. Similar are selling for $3 a piece now at Costco. Is that cheap? |
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On Thu, 09 Feb 2017 20:03:13 -0000, trader_4 wrote:
On Thursday, February 9, 2017 at 2:35:23 PM UTC-5, James Wilkinson Sword wrote: On Thu, 09 Feb 2017 17:38:16 -0000, trader_4 wrote: On Thursday, February 9, 2017 at 10:15:52 AM UTC-5, James Wilkinson Sword wrote: On Thu, 09 Feb 2017 14:53:02 -0000, westom wrote: On Wednesday, February 8, 2017 at 5:18:18 PM UTC-5, James Wilkinson Sword wrote: I can't believe it's that likely for 4800V to get onto a 240V line. Possible, but so rare it's not worth bothering to install protection. I protect against little spikes, or voltages about 30V under/over what they should be. 30 volts and higher is already solved inside each appliance. Why would anyone spend money to protect from something that does not even cause damage? That is already made irrelevant by what already must exist inside every appliance? Might do in quality appliances, but not cheap ones, or LED lightbulbs. Even cheap appliances have MOVs for small surges and will tolerate the ~ 12% overvoltages you're talking about. I don't have much experience with LEDs, but see no reason why they can't tolerate your 12% over voltage for seconds. More like about 3 hours. What kind of backward country are you living in over there? If I had over voltages of 30 volts happening for even seconds at a time, the power company would come out, find out what's wrong, and fix it. We are given 230V +/- 10% (not sure of the exact percentages). Unless it goes outside that, they are not obligated to do anything. It appears they recently fitted a new transformer presumably to cater for higher usage, which is currently running nowhere near full capacity, and therefore over voltage. The electrician I got sent out by the power company said they can step it down, but don't have to as it's within legal limits. If all these things were as sensitive as you claim, we'd see a lot of failures. I sure don't. Do you have 3 hours of 30 volts over? Since we are at 120V, No, you have 240 aswell. that would be 15 volts over, and no, I don't have 15 or 30 volts over. WTF is wrong over there? Transformer loads change the voltage. Do you have cheap LED lightbulbs? I have some 5" retrofits for recessed lights that I paid $10 a piece for. Similar are selling for $3 a piece now at Costco. Is that cheap? Yes. -- What advice don't you want to hear from a doctor before an operation? "Whatever you do, don't go into the light." |
#27
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On Thu, 09 Feb 2017 20:03:13 -0000, trader_4 wrote:
On Thursday, February 9, 2017 at 2:35:23 PM UTC-5, James Wilkinson Sword wrote: On Thu, 09 Feb 2017 17:38:16 -0000, trader_4 wrote: On Thursday, February 9, 2017 at 10:15:52 AM UTC-5, James Wilkinson Sword wrote: On Thu, 09 Feb 2017 14:53:02 -0000, westom wrote: On Wednesday, February 8, 2017 at 5:18:18 PM UTC-5, James Wilkinson Sword wrote: I can't believe it's that likely for 4800V to get onto a 240V line. Possible, but so rare it's not worth bothering to install protection. I protect against little spikes, or voltages about 30V under/over what they should be. 30 volts and higher is already solved inside each appliance. Why would anyone spend money to protect from something that does not even cause damage? That is already made irrelevant by what already must exist inside every appliance? Might do in quality appliances, but not cheap ones, or LED lightbulbs. Even cheap appliances have MOVs for small surges and will tolerate the ~ 12% overvoltages you're talking about. I don't have much experience with LEDs, but see no reason why they can't tolerate your 12% over voltage for seconds. More like about 3 hours. What kind of backward country are you living in over there? If I had over voltages of 30 volts happening for even seconds at a time, the power company would come out, find out what's wrong, and fix it. If all these things were as sensitive as you claim, we'd see a lot of failures. I sure don't. Do you have 3 hours of 30 volts over? Since we are at 120V, that would be 15 volts over, and no, I don't have 15 or 30 volts over. WTF is wrong over there? We're not the ones with 11kV lines falling onto 240V lines. -- What advice don't you want to hear from a doctor before an operation? "Whatever you do, don't go into the light." |
#28
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[FoxNews]A small town's sudden power surge fried tech gear in hundreds of homes
"James Wilkinson Sword" writes:
On Wed, 08 Feb 2017 22:13:00 -0000, Phil Hobbs wrote: On 02/08/2017 05:00 PM, James Wilkinson Sword wrote: On Wed, 08 Feb 2017 21:55:06 -0000, Phil Hobbs wrote: On 02/08/2017 02:46 PM, James Wilkinson Sword wrote: On Wed, 01 Feb 2017 17:31:50 -0000, Mr. Man-wai Chang wrote: A small town's sudden power surge fried tech gear in hundreds of homes You should have anything expensive in a UPS. Big help if the house burns down. I've heard of folks getting MOVs put in right at the meter, outside the house. In that sort of super nasty surge, they explode and isolate the house from the line. Never had the urge to do it myself, but it might be good insurance. Wouldn't a really big surge destroy the first thing it hits, i.e. the main fuse, meter, etc? It matters where the big arc happens, though. You don't clear a high energy 1600-4800V circuit with a domestic 240V breaker, that's for sure. The result is an _arc flash_, which you do _not_ want in your vicinity, trust me. (Youtube has a lot of examples if you doubt this.) Having a major league arc flash on a cinderblock foundation outside the house is a very different proposition from having one in a breaker box mounted to a wooden stud wall inside, for one thing, but I'm outside my experience here, so I'll happily defer to any actual power engineering types who want to chime in. I can't believe it's that likely for 4800V to get onto a 240V line. Possible, but so rare it's not worth bothering to install protection. I protect against little spikes, or voltages about 30V under/over what they should be. My UPS frequently adjusts the voltage, and sometimes gives up and runs the house on batteries for 5 seconds. Well, it did happen to us. The pole with the transformer broke between the transformer and the crossarm at the top, partly because it was an old pole with ants living in the part that broke and partly because of the winter storm. I saw the aftermath and even still have the two 4800V cutouts that fed the transformer. This was a bunch of summer cottages on a lake. Two of them burned to the ground. Our place was on the same transformer but because my father always threw the main breaker when closing up the place it was unaffected. |
#29
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On Thursday, February 9, 2017 at 3:10:34 PM UTC-5, James Wilkinson Sword wrote:
We are given 230V +/- 10% (not sure of the exact percentages). Unless it goes outside that, they are not obligated to do anything. It appears they recently fitted a new transformer presumably to cater for higher usage, which is currently running nowhere near full capacity, and therefore over voltage. Transformer increases or decreases voltage to adjust for varying loads. These adjustments occur many times daily. That is a less than 10% (acceptable) variance. If voltage cannot be maintained (if too high or too low), then utility equipment disconnects power to protect consumer appliances. Concern is for voltages so high (and short) as to cause damage. So protection is installed both by the utility and by a consumer using a properly earthed solution. Defined are the two layers of protection. Every protection layer is only defined by an item that does protection - earth ground. A protector without earth ground is not a layer of protection. |
#30
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On Thu, 09 Feb 2017 23:18:47 -0000, westom wrote:
On Thursday, February 9, 2017 at 3:10:34 PM UTC-5, James Wilkinson Sword wrote: We are given 230V +/- 10% (not sure of the exact percentages). Unless it goes outside that, they are not obligated to do anything. It appears they recently fitted a new transformer presumably to cater for higher usage, which is currently running nowhere near full capacity, and therefore over voltage. Transformer increases or decreases voltage to adjust for varying loads. These adjustments occur many times daily. That is a less than 10% (acceptable) variance. If voltage cannot be maintained (if too high or too low), then utility equipment disconnects power to protect consumer appliances. I asked the power company about that. They tell me that function is only available on the higher voltage transformers. The final stepdowns are manual only. Concern is for voltages so high (and short) as to cause damage. So protection is installed both by the utility and by a consumer using a properly earthed solution. Defined are the two layers of protection. Every protection layer is only defined by an item that does protection - earth ground. A protector without earth ground is not a layer of protection. -- If the Pope goes #2, does that make it "Holy ****"? |
#31
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[FoxNews]A small town's sudden power surge fried tech gear in hundreds of homes
"James Wilkinson Sword"
news alt.home.repair, wrote: On Wed, 01 Feb 2017 17:31:50 -0000, Mr. Man-wai Chang wrote: A small town's sudden power surge fried tech gear in hundreds of homes Full story: http://www.foxnews.com/tech/2017/01/...dden-power-sur ge-fried-tech-gear-in-hundreds-homes.html Residents in the small Pennsylvania town of Brookville must've wondered what on earth was going on earlier this month when a sudden power surge caused electrical appliances and gizmos in up to 1,000 homes to fry, explode, or simply conk out. What may have momentarily seemed like some kind of weird supernatural happening was actually an electrical surge caused by a failed power line component, according to an AP report. Local media said that "damage ranged from residents losing a refrigerator to losing all appliances in the kitchen or losing everything in the house." Up to a quarter of the town's 4,000 residents were thought to have been affected by the incident, with many reporting fried computers, burned electrical meters, and damaged power strips. Some even spoke of fluorescent lights suddenly exploding. When the surge occurred, the high volume of calls flooding into the emergency services forced the local fire department to call for extra help from three nearby facilities. As for the local cops, the incident tripped its main office radio, causing them to miss the first emergency calls. The first they knew something was up was when they heard the fire trucks roaring through the town. "We were fortunate that nobody was hurt," Tracy Zents, the director of Jefferson County's Department of Emergency Services, told AP. You should have anything expensive in a UPS. The UPS would have fried as well under those conditions. And, depending on internal UPS design characteristics, may/may not have done any good for the device plugged into it. It depends on several things. Which lines got energized way above the normal voltage and for how long. Is the UPS truely seperating the inverter/battery backup from the main AC line, or, is it a cheaper unit where the plugins aren't actually isolated from the main incoming power? IE: is it really running the out plugs on battery via inverter or, is it also supplying filtered power while the AC is good via the ac lines feeding the UPS? If it's isolating the battery and charging circuitry then, your risk of being toasted if something roasts the ups is smaller, but, not by much. -- Sarcasm, because beating the living **** out of deserving people is illegal. |
#32
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[FoxNews]A small town's sudden power surge fried tech gear in hundreds of homes
Phil Hobbs
Wed, 08 Feb 2017 21:55:06 GMT in alt.home.repair, wrote: On 02/08/2017 02:46 PM, James Wilkinson Sword wrote: On Wed, 01 Feb 2017 17:31:50 -0000, Mr. Man-wai Chang wrote: A small town's sudden power surge fried tech gear in hundreds of homes Full story: http://www.foxnews.com/tech/2017/01/...udden-power-su rge-fried-tech-gear-in-hundreds-homes.html Residents in the small Pennsylvania town of Brookville must've wondered what on earth was going on earlier this month when a sudden power surge caused electrical appliances and gizmos in up to 1,000 homes to fry, explode, or simply conk out. What may have momentarily seemed like some kind of weird supernatural happening was actually an electrical surge caused by a failed power line component, according to an AP report. Local media said that "damage ranged from residents losing a refrigerator to losing all appliances in the kitchen or losing everything in the house." Up to a quarter of the town's 4,000 residents were thought to have been affected by the incident, with many reporting fried computers, burned electrical meters, and damaged power strips. Some even spoke of fluorescent lights suddenly exploding. When the surge occurred, the high volume of calls flooding into the emergency services forced the local fire department to call for extra help from three nearby facilities. As for the local cops, the incident tripped its main office radio, causing them to miss the first emergency calls. The first they knew something was up was when they heard the fire trucks roaring through the town. "We were fortunate that nobody was hurt," Tracy Zents, the director of Jefferson County's Department of Emergency Services, told AP. You should have anything expensive in a UPS. Big help if the house burns down. I've heard of folks getting MOVs put in right at the meter, outside the house. In that sort of super nasty surge, they explode and isolate the house from the line. Never had the urge to do it myself, but it might be good insurance. I've been onsite a few times when the MOVs have kicked in and done their job. It greatly reduces harm to the electrical system and devices attached inside the home. However, if the surge is strong enough, it'll momentarily arc across the now opened lines and temp energize the home. It's still better than maintaining a direct (but burning) link, though. -- Sarcasm, because beating the living **** out of deserving people is illegal. |
#33
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[FoxNews]A small town's sudden power surge fried tech gear in hundreds of homes
Mark F
Thu, 09 Feb 2017 14:23:17 GMT in alt.home.repair, wrote: I'd say all appliances should be replaced by the power company if any in the house failed, or at least anything that fails in the next 5 years should be replaced when it fails. I've had very little success getting power companies to replace anything in a home due to an electrical malfunction that was their fault. As far as they seem to be concerned, your appliances and protection for them is your responsibility. Even if their transformer sends way too much juice to your house, that's somehow, not their fault. I can understand their position on it, but, I also see it from the owner of now dead electronics/electrical devices in their home. Also: A UPS is more likely to get fried itself in the cases like in the above report. House MOV seems like the only hope to protect from these events. They do a reasonably decent job too. However, they cannot do a damn thing if the incoming voltage has enough amps to jump across the now open lines inside the meter box. If the current is high enough, a couple of inches of space isn't going to make a difference, it'll jump (it's not a stable connection, but it's a connection) across and complete the previously opened circuits. It won't be able to maintain it for very long, assuming other safety circuits are kicking in around this time and shutting it down, OR, it finally burns enough off during the arc jump that it can't hold anymore. Until one or both happens though, your house is being energized, and likely way more than anything plugged in inside the house is going to be happy with. -- Sarcasm, because beating the living **** out of deserving people is illegal. |
#34
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[FoxNews]A small town's sudden power surge fried tech gear in hundreds of homes
"James Wilkinson Sword"
news alt.home.repair, wrote: Not LED lightbulbs, they're too cheap to have that protection. And my computer is not protected against 5 second outages. The system shuts off and corrupts the hard disk. What OS are you using? Depending on what the computer was doing at the time of power loss, the corruption should be miminal and/or non existant. It usually happens with delayed writes that don't occur at all, or were in progress when the power was lost. This is sadly, the price you pay for modern operating systems that have files loaded all the time and do read/writes in the background and not when you initially thought. IE: when you saved the .doc file, your changes may not have been committed to physical storage yet. The OS might be waiting until it has more information to write out. If you lose power in one of those states, you could corrupt files and/or various aspects of the file system itself. -- Sarcasm, because beating the living **** out of deserving people is illegal. |
#35
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[FoxNews]A small town's sudden power surge fried tech gear in hundreds of homes
westom
Thu, 09 Feb 2017 14:53:02 GMT in alt.home.repair, wrote: My friend knows someone who knows this stuff. So he had a 'whole house' protector. His electric meter was also damaged. But nothing else. Even the 'whole house' protector was not damaged. In part, because it was properly earthed. In part? Er, no. That's the primary reason the protector and everything else wasn't damaged/destroyed. Your house protector does the same thing the plugin surge protectors do on a larger level. It tries to redirect excess current on either/both legs to ground, to bleed it off as quickly as is possible. Transients created by lightning, linemen errors, tree rodents, stray cars, and insulator failures are rare. So we properly earth a 'whole house' solution for about $1 per protected appliance. Then such threats do not cause hardware damage - even to that 'whole house' protector. As long as the ground is good. If the ground is damaged for some reason as part of the massive overcurrent issue, the protection devices have nothing to work with, whatever they can't surpress with their own electronics on board is going to travel throughout the house. Some surge supressors will attempt to bleed into the neutral lines as well, but, as I said, if those lines are damaged, it has nowhere to bleed off that excess current. It's electronics will sacrifice themselves trying to stop the surge, but, if the surge is strong enough and of a sufficient duration, the protective device will give up everything it's got and sadly, some current is still getting past it. -- Sarcasm, because beating the living **** out of deserving people is illegal. |
#36
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[FoxNews]A small town's sudden power surge fried tech gear in hundreds of homes
trader_4
Thu, 09 Feb 2017 17:38:16 GMT in alt.home.repair, wrote: On Thursday, February 9, 2017 at 10:15:52 AM UTC-5, James Wilkinson Sword wrote: On Thu, 09 Feb 2017 14:53:02 -0000, westom wrote: On Wednesday, February 8, 2017 at 5:18:18 PM UTC-5, James Wilkinson Sword wrote: I can't believe it's that likely for 4800V to get onto a 240V line. Possible, but so rare it's not worth bothering to install protection. I protect against little spikes, or voltages about 30V under/over what they should be. 30 volts and higher is already solved inside each appliance. Why would anyone spend money to protect from something that does not even cause damage? That is already made irrelevant by what already must exist inside every appliance? Might do in quality appliances, but not cheap ones, or LED lightbulbs. Even cheap appliances have MOVs for small surges and will tolerate the ~ 12% overvoltages you're talking about. I don't have much experience with LEDs, but see no reason why they can't tolerate your 12% over voltage for seconds. If all these things were as sensitive as you claim, we'd see a lot of failures. I sure don't. Neither have I. I've taken apart a few that have had driver circuit failures (The LED itself was still good and can be repurposed for other projects), while I found the driver circuitry to be on the cheap side, they did have MOVs present. It seems to be mostly a heat issue with the ones I've taken apart that kills them. IE: excess heat buildup in the bottom of the bulb where the components live without a reliable way to pull the heat away. The electronics essentially wind up cooking themselves over time. The ones I've taken apart so far aren't using actual transformers to drop the voltage, they opted for the resistor pack route instead; which generates that much more heat, with no place to go in a sealed LED bulb. Saves on physical weight, etc, because it's not using a transformer, but, the tradeoff I don't think is the better option. I won't claim all of them are done this way, as obviously, I haven't taken apart every single make/model LED screw in replacement bulb out there. But, several from GE and whoever actually makes Walmarts off brand are not using voltage reducing transformers. And, you can tell where the components are getting the warmest on the little circuit boards inside them... -- Sarcasm, because beating the living **** out of deserving people is illegal. |
#37
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[FoxNews]A small town's sudden power surge fried tech gear in hundreds of homes
Phil Hobbs
Wed, 08 Feb 2017 22:13:00 GMT in alt.home.repair, wrote: It matters where the big arc happens, though. You don't clear a high energy 1600-4800V circuit with a domestic 240V breaker, that's for sure. The result is an _arc flash_, which you do _not_ want in your vicinity, trust me. (Youtube has a lot of examples if you doubt this.) The arc flash isn't even the big killer. It's the shockwave ahead of the arc flash that does the most damage if the voltage/amperage is high enough. It can turn your organs into mush before the fireball gets close enough to light you up. Having a major league arc flash on a cinderblock foundation outside the house is a very different proposition from having one in a breaker box mounted to a wooden stud wall inside, for one thing, but I'm outside my experience here, so I'll happily defer to any actual power engineering types who want to chime in. When I'm tasked with the job of bringing circuits online, I tend to do it with a long plastic stick at an angle; I'm stepping off to the side. This way, if something is wrong, I don't get the shockwave and arc flash right in my face. Nothing like finishing out a premod home only to findout one or more wires wasn't labeled correctly and one is actually about to feed 120 into the live side of a 120volt breaker that's living on the other leg. So, when you turn this breaker on, you're actually running both legs into each other on that breaker. It shoots fire out the sides and hums something awful before it trips right back out. Atleast with the cinderblock foundation, it's essentially an open environment so the arc flash and shockwave can dissipate faster. When it's enclosed (as in, inside a panel), it can be much more devastating. Not only for the panel and it's guts, but, yours too. -- Sarcasm, because beating the living **** out of deserving people is illegal. |
#38
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On Thursday, February 9, 2017 at 6:43:06 PM UTC-5, James Wilkinson Sword wrote:
They tell me that function is only available on the higher voltage transformers. The final stepdowns are manual only. Correct. Explains why the utility can only regulate to within 10%. And also why larger variations result in that one transformer cutting off power to all those local transformers. If that one higher voltage transformer does not maintain voltage variations, then a circuit that feeds local transformers is modified so that voltage varies by less than 10% at every time. If voltage gets too high or too low, then power is cut off to avert damage to consumers appliances. |
#39
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On Thursday, February 9, 2017 at 9:36:52 PM UTC-5, Diesel wrote:
In part? Er, no. That's the primary reason the protector and everything else wasn't damaged/destroyed. Your house protector does the same thing the plugin surge protectors do on a larger level. It tries to redirect excess current on either/both legs to ground, to bleed it off as quickly as is possible. You assumed resistance is relevant. It is not. Impedance is the relevant parameter. Plug-in protectors are all but completely disconnected from earth ground. Plug-in protectors must somehow 'block' or 'absorb' that energy.. Plug-in protectors operate completely different from a properly earthed 'whole house' protector. An answer without numbers is best ignored as speculation. That plug-in protector may connect to a breaker box by wire that is well less than 0.2 ohms resistance. That same wire may be 120 ohms impedance. If that plug-in protector tried to earth a tiny 100 amp surge, then 100 amps times 120 ohms impedance means protector and appliances approach 12,000 volts. Plug-in protectors can make appliance damage easier if not part of a properly earthed 'whole house' solution. Surge current finds earth destructively via attached or other nearby appliances. An example of why plug-in protectors can even make surge damage easier if a properly earthed 'whole house' solution does not exist. We saw this even in studies that were even submitted for design review. In one case, a network of powered off computers were 'protected' by plug-in protectors. Those protectors earthed a surge destructively through the entire network. Best connection to earth was incoming via the network and outgoing destructively to earth via modems. Since both phone and TV cable already have effective protection for free as required by codes. Solution was to replace every damaged semiconductor (which is why we knew every surge current path), remove those plug-in protectors (that have no earth ground), and implement properly earthed 'whole house' protection. Then no future damage occurred (in a location that suffered a high incident of lightning ground strikes). 'Whole house' and plug-in protectors are completely different. A most significant reason why: plug-in protectors have no low impedance (ie less than 3 meter) connection to earth. 'Whole house' protectors are only effective IF that low impedance (as short as possible with no sharp wire bends) connection to earth exists. |
#40
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[FoxNews]A small town's sudden power surge fried tech gear inhundreds of homes
On Fri, 10 Feb 2017 16:24:16 -0000, westom wrote:
On Thursday, February 9, 2017 at 6:43:06 PM UTC-5, James Wilkinson Sword wrote: They tell me that function is only available on the higher voltage transformers. The final stepdowns are manual only. Correct. Explains why the utility can only regulate to within 10%. And also why larger variations result in that one transformer cutting off power to all those local transformers. If that one higher voltage transformer does not maintain voltage variations, then a circuit that feeds local transformers is modified so that voltage varies by less than 10% at every time. If voltage gets too high or too low, then power is cut off to avert damage to consumers appliances. Doesn't make sense to me. If power usage is very high on one of the final transformers, it needs to be able to adjust its stepping to maintain the correct voltage. Or do they assume all areas' usage changes together? -- If god is so amazing, why did the dinosaurs die out? |
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