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Is anyone here a UK electrician? If so how would you recommend someone enter the trade, I've seen two primary methods, one is pay to enrol on a course for that and the other is become an apprentice, is one better than the other, does it make a difference to what you can go on to do? How is the job market for electricians in the UK?
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Jul 10, 2013 01:09
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This morning I heard a loud boom and my electricity went out and came back on not to long after, so my understanding is a transformer blew, hit one of the electric company's super circuit breakers which auto reset shortly there after. I've had it happen before, no big deal. But the weird thing is like half my stuff wouldn't work or was acting weird, half worked fine. Even my hair dryer was working but acting weird, like I'd just didn't sound right. I assumed it was a power surge an expected to be going through an annoying insurance process. Then right before I left for work my power went out completely and I could see the electric company replacing everything on the pole that goes into my building. Everything, the insulators, all but the big wiring and some box that I've always wondered about, I assume it's a power monitor of some kind, it's slightly wider as the pole, maybe 8 inches high and 4 inches thick high up the pole. I mean I assume it is the electric company's thing since it is so high up the pole and it was new when I got home. Oh and there is no transformer on the pole. So what's the deal here? I thought electricity was an all or nothing type thing but when I got home everything was working fine. Any idea what actually happened here? Can a transformer just kind of blow and gently caress up your electricity in a way that made some stuff work and others not or act weird? And why were they replacing everything on the pole that just has wires running down into the ground including stuff like insulators?  lovely cropped iPhone photo, mysterious silver box is directly opposite the lower bucket thing. The other wires also were wrapped in orange stuff with little orange tents over the wire hook thingy clipped on, I assume to keep you from accidentally touching live wires when working on something else. Three Olives fucked around with this message at 00:20 on Jul 11, 2013 |
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Jul 11, 2013 00:14
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It could have been a brown-out. A brown-out is when the voltage supplied to your home is lower than normal. Think of it like turning down a dimmer switch, but on your whole neighborhood. Lights might be dimmer, and other things will behave strangely. Electronics probably will either work normally, or not work at all.
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Jul 11, 2013 00:33
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Three Olives posted:So what's the deal here? I thought electricity was an all or nothing type thing but when I got home everything was working fine. Any idea what actually happened here? Can a transformer just kind of blow and gently caress up your electricity in a way that made some stuff work and others not or act weird? And why were they replacing everything on the pole that just has wires running down into the ground including stuff like insulators? You were experiencing a brownout, where the voltage coming in is lower than it's supposed to be. Those can be caused by trees contacting the power line and creating a path for electricity to flow to the ground, effectively "leaking" electricity and lowering the "electricity pressure" to your apartment. If they were replacing that entire pole, it's possible one of the insulators had failed or something else about the pole was grounding the line.
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Jul 11, 2013 00:38
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The thing about the brownout is that it only was on one phase. But we'd need to see how the apartment complex was connected to the grid. No, electricity doesn't necessarily need to be an "all or nothing" deal. You can get all manner of problems. I can't be certain without being in your apartment at the time with a multimeter (and maybe an oscilloscope) to check the outlets, but you probably have an Edison system - two 120V lines and a neutral. If you connect a load between the line and neutral you get 120V, between both lines you get 240V. My guess is something caused a sustained undervoltage on one of the phases. (Like 75V instead of 120V.) That would cause both 240V and 120V loads connected to that phase to have problems. Some loads like switching power supplies might be able to operate by drawing more current at a lower voltage, which might be why some things worked and others didn't. Some loads, like the motor in the hair dryer, may be damaged by operating at a lower voltage. Next time, if you suspect something weird is going on, I'd strongly recommend turning off and unplugging any expensive/sensitive loads even if you have them connected via a surge arresting power strip. Yes, it is possible for something going wrong inside the transformer to put out an abnormal voltage. You have windings in the transformer that drop the voltage down to a usable level. If you have a fault that causes some of the secondary windings to short out, you could get an abnormally low voltage on the outlet. Based on the information we have to work with it's hard for me to say. Was that box a transformer or something else like a capacitor bank? As far as the orange blankets go, yes, they're rubber insulators for safety - preventing shock and reducing the risk of a short that could cause an arc flash. Three-Phase fucked around with this message at 00:46 on Jul 11, 2013 |
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Jul 11, 2013 00:43
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Three-Phase posted:There were a few things absent that would have helped make it an authentic control room experience. Namely a radio playing the local 60s/70s station, and partially completed crossword and Sudoku puzzles strewn about the consoles. And the taped-over indicators and the backlog of alarms that are broken and haven't been fixed yet. (Some plants are much worse than others as far as faulty alarms. "Yeah, that thing has indicated a high alarm for the past ten years so we ignore it.") Danger tags and no plant manuals, along with guides to "INSTALL HERE" or "MADE OBSOLETE BY REV 10?" Also the scram sounds nice, but where is the loss of all lighting?
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Jul 11, 2013 01:02
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This place is awesome, I wouldn't know who to ask these questions to otherewise. I called the front desk first to make sure it was safe to take the elevators and asked about it and they said a transformer blew which fit with the loud pop sound I heard when my power went out but it could have been a coincidence, it woke me up and they are doing major excavating down the street so a million huge trucks empty and full are driving by every morning. A neighbor of mine that I saw in the elevator tonight said he heard it was the result of a crispy squirrel but who knows. As for wiring my understanding is it is kind of weird, it's a highrise and then like every 5 floors we have an electrical closet with power company meters in it, every other place I have seen has a centralized meter bank, not sky meters. All the common elements are separate so the back up generator kicked in. We do have 240 power in the units but my oven looked normal although I didn't try and use it. The thing that was acting weird is I have a big led message board that I use as a clock in my livingroom, it started continuously beeping and a few random LEDs lit up, my cable modem worked fine as did my TiVo but my tuning adaptor wouldn't turn on and they are plugged into the same outlet. Three Olives fucked around with this message at 17:00 on Jul 11, 2013 |
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Jul 11, 2013 01:03
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Even if your electronics are on the same circuit, their power supplies will have different sensitivities to the brown-out. Really cheap power supplies will put out a correspondingly lower voltage. Nicer ones will notice that they can't put out their normal voltage and will switch off entirely. Others will still be able to put out their full voltage and will happily chug along.
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Jul 11, 2013 01:18
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If you are in an apartment complex that big, I'm starting to wonder if the device on that pole is not feeding your complex. I've seen complexes with a larger transformer on a pad outside that then feeds into a room that has meters and power distribution equipment. (You might be able to put the transformer indoors but you need to be very careful about it - it depends on what codes apply.) Ryand-Smith posted:Danger tags and no plant manuals, along with guides to "INSTALL HERE" or "MADE OBSOLETE BY REV 10?" Upset/panicked engineers and unusually cool and collected (seemingly indifferent) operators. (Those are the best operators, FYI.) Three-Phase fucked around with this message at 01:37 on Jul 11, 2013 |
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Jul 11, 2013 01:31
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Three-Phase posted:If you are in an apartment complex that big, I'm starting to wonder if the device on that pole is not feeding your complex. It's a 23 story highrise, the generator is in the basement, the lines from the pole go straight into the ground, like, giant electric cables, insulator, tiny wire, insulator, giant power cables going into the ground into the building somewhere. The device on the poll is a realitively small thing, like small enough to easily hold in your hands.
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Jul 11, 2013 01:36
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Did you see anything written or stenciled on the box like "100KVA" or something like that?
Three-Phase fucked around with this message at 01:43 on Jul 11, 2013 |
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Jul 11, 2013 01:39
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The correct response to a suspected brownout is to immediately open the main service breaker(s). Brownouts do all manner of bad things to your nice stuff. Ask me how I know. 
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Jul 11, 2013 03:48
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Thanks for such an interesting thread! Some of the safety/horror stories in here remind me of exactly how UN-safe some of my work conditions actually were, working stage crew when I was in school. Some of the poo poo was so unsafe my Local actually forbade anyone from working at a particular venue until their system was overhauled and had proper safety equipment and practices in place (never learned if it was done or not...luckily no one was hurt by electricity back then, but there were a couple close calls!) A question for Three-Phase: How many years would you say you were in training/went to school for your line of work? And how long have you been in the industry as your primary career, if you don't mind me asking? I'm not trying to be nosy, just curious how long it would take for someone with your experience to get to the point that you are  You do indeed sound like you certainly know what you're talking about!I've really enjoyed this thread and the occasional Bitcoin thread electricity derails in GBS, I've probably learned more from both threads than I've remembered/forgotten/didn't-know through any school or work experience. Thanks again!
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Jul 11, 2013 05:00
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MrYenko posted:The correct response to a suspected brownout is to immediately open the main service breaker(s).
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Jul 11, 2013 10:47
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MrYenko posted:
Same here, lost electronics to lightning as well as brown outs. Now the spendy stuff gets power from a UPS, been using them for years, through multiple power outages without problem. The money spent is worth the peace of mind alone IMO.
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Jul 11, 2013 13:13
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He's probably got three-phase power coming into the building, and a squirrel shorted one phase to ground, so the delta-wye transformer in the basement is working on open delta, so there's one leg that's super low. I'm 95% sure that square box on the pole is a power quality monitor or a smart meter relay/concentrator.
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Jul 11, 2013 15:21
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babyeatingpsychopath posted:He's probably got three-phase power coming into the building, and a squirrel shorted one phase to ground, so the delta-wye transformer in the basement is working on open delta, so there's one leg that's super low. I'm 95% sure that square box on the pole is a power quality monitor or a smart meter relay/concentrator.
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Jul 11, 2013 21:45
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eljackass posted:A question for Three-Phase: How many years would you say you were in training/went to school for your line of work? And how long have you been in the industry as your primary career, if you don't mind me asking? I'm not trying to be nosy, just curious how long it would take for someone with your experience to get to the point that you are I got a BS-EET degree at college. It had most of the core pure-EE stuff (including a difficult semester of differential equations) with a lot of material that was more oriented for industry. As far as the point I'm at, I'm still starting out after about seven years, I have a long way to go. (Eventually getting a PE.) I just gravitated towards the more power-oriented stuff out of college, some of it was random chance, and learning a lot from extremely knowledgeable people outside of college. Once you're done with school, whatever that may be, you need to keep learning. I'm not sure where the future will lead me in this field. But I intend to never stop learning no matter my situation. Some people think I should be a teacher someday. When I discuss electrical stuff sometimes it almost feels to me more like I'm, well, "preaching" to a congregation than teaching people. grover posted:Loss of one phase to a delta-wye transformer can result in partial voltages on two phases of the wye secondary through magnetic interaction in the transformer's core and cause bad brownout conditions and other issues. Unless the system has specific relaying to detect an (unshorted) open line, it's not going to trip and will put out bad voltage. That makes sense. I still am confused as to what that drat box on the side of the pole is, if it really is a transformer.
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Jul 11, 2013 23:31
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Three-Phase you obviously know so much more than my working knowledge of electrical... my marine course obviously included a lot of electro for obvious reasons but you clearly know a lot more than I do, so I guess what I'm saying, is we need a chief electrician who doesn't have his head up his rear end. Also I totally agree with what's been said, sounds like a loss of one phase.
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Jul 12, 2013 02:26
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Three-Phase, what kind of hoops are you going to have to jump through to get a PE with a BS-EET?
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Jul 12, 2013 03:14
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I would probably throw up right into the MCC bucket. And die. I cannot think of a much more ignominious death than "electrocuted via vomit".
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Jul 12, 2013 03:15
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Anti-Hero posted:Three-Phase, what kind of hoops are you going to have to jump through to get a PE with a BS-EET? You just need a lot more time in the field. So it is just time. I did get the Ohio FE/EIT done awhile back, that was a tough, long test. It's like getting into orbit, once you get the FE done you're more than halfway there. But it isn't going to be easy and I still have a hell of a lot more to learn and refresh. Four year EET (I think they have a new name for a similar course nowadays) was OK for Ohio but of course it must be an accredited by ABET college.
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Jul 12, 2013 03:18
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You'll be fine. You sound way more interested in the field than I am (I'm referring to your interest outside work), and I muddled my way in to a license. I have faith.
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Jul 12, 2013 03:21
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Anti-Hero posted:Three-Phase, what kind of hoops are you going to have to jump through to get a PE with a BS-EET? They'll waive the FE requirement if you've got a doctorate or 20 years experience and let you sit just for the PE, though. grover fucked around with this message at 14:34 on Jul 12, 2013 |
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Jul 12, 2013 14:30
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This will be neat for people who have never seen this: here are some examples of big Direct-buried 15-35kV underground cable 15kV Submarine cable (When you need to get electricity to an island!) Armored 15kV triplex cable (When you need to move high voltages around indoors.) At the highest rated triplex in a cable tray, that four-inch (outer diameter of the shield, the biggest part) cable can carry fourteen megawatts at 13000V. If need more current at high voltages, you can use phase-isolated bus ducts. If you need to move thousands and thousands of amps at hundreds of thousands of volts or even upwards of a million volts (hundreds to thousands of megawatts), you use gas-insulated ducts and gas-insulated switchgear. Three-Phase fucked around with this message at 20:37 on Jul 12, 2013 |
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Jul 12, 2013 19:52
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One of my coworkers used to work for ABB. He was visiting customer site in South America, and was walking down some sort of hallway, and one side had a chain link fence for a wall. Something didn't quite feel right, and realized on the other side of that fence, within a foot or two, was an un-insulated high voltage "bus duct".
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Jul 12, 2013 20:09
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I think you meant to say MV cables.  Coincidentally, starting yesterday and continuing on for the next couple of months I'm testing a fuckton of 25kV cables and distribution equipment at a data center. Would take pics and/or videos but I'm prohibited from doing so per a confidentiality agreement.
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Jul 12, 2013 20:18
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Noctone posted:25kV cables ... data center... confidentiality agreement.  Insert NSA joke here.
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Jul 12, 2013 20:21
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Noctone posted:I think you meant to say MV cables. drat, I'm supposed to be the one to correct people on that!
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Jul 12, 2013 20:38
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What is a semiconducting strand screen?
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Jul 12, 2013 20:56
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FrozenVent posted:
Not this time but we have worked at an NSA data center before I think (but not me personally). Three-Phase posted:drat, I'm supposed to be the one to correct people on that! To be fair, 25kV is HV according to some standards (NEC maybe? I forget.)
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Jul 12, 2013 21:55
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squeakygeek posted:What is a semiconducting strand screen? My understanding is that the two semiconductor screens (material that is not as conductive as the copper conductor, but not as resistive as the EPR insulator) help dissipate the voltage evenly. It's sort of like lying flat on a concrete floor versus lying on a mattress. It's also important when you are terminating the cable, if you have a cable that doesn't have the semiconductor layers, you need to use a different approach like building "stress cones" on the termination so you don't generate electrical stress between ring at the end of the shielding and the conductor. I assisted with terminations involving a cable that had the semiconductor layers, and you almost cut the individual conductors like it's shown in the picture (with much more of the huge armored outer section removed, of course.) As far as stress goes, this is also part of what the foil sheild is for. That shield around the insulator makes sure there isn't a point of uneven electrical stress where a premature degradation leading to failure could occur. When you are at higher voltages (I believe over 2400V) you need to have shielded cable. There is a specific exception to shielding - you can use unshielded high voltage cables inside a piece of equipment, like a motor, a piece of switchgear, etc. where it isn't subject to damage or contact by personnel. However, despite it being insulated, you should treat it as if it was a bare wire. That means you must be very careful to avoid touching ground, other cables, and soforth. Because that point where the cable touches the ground, on that part of the circumference you will generate a lot of stress. (I've seen the leads for large motors, they look similar but I'm not sure how they get away with seemingly breaking that rule.) There is a video on this site that does a good job explaining the stresses. And another video on terminations which such jaunty music!  Bad installation that failed at a fairly low hi-pot (high potential) test. Three-Phase fucked around with this message at 23:51 on Jul 12, 2013 |
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Jul 12, 2013 23:24
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What use is it to get a PE when you're a EE? I've only ever met 1 PE that wasn't a Civil or Mechanical engineer, and he works at my company. He's a controls engineer (we all are), but mostly does software. He knows his hardware and is pretty good at NEC/UL interpretation, but I haven't a clue what someone like him would do with his PE. I would understand that as a power engineer, having a PE would be pretty important. Is that about the extent of it? I never took my FE. I might have been able to pass it in college, but I would most certainly fail now that I'm 5.5 years out. I'm more of a software guy, at least that's what I'm trying to focus on, even though right now I'm the 2nd person people go to at my company when they have NEC/UL questions. Hell, just spent nearly 4 hours yesterday flipping around the NEC trying to figure out how to size a specific conductor, and dammit I think I found it after 40+ years of nobody in our company knowing how to do it properly. Is there any use for me to go for my PE? If I weren't doing controls, I'd be doing embedded software or something...hardly an area where people have a PE.
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Jul 13, 2013 00:46
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I'm not that sure to be completely honest, besides some opportunity for forward advancement.
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Jul 13, 2013 00:59
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I'm sure there are uses for a PE in electrical engineering, but my personal experience is pretty much what Three-Phase just said. Some places it helps with moving up the ladder because it's a hoop you can jump through that's easily identifiable to middle management. It definitely helps with finding job opportunities, I remember seeing it listed as a requirement or preference on a lot of job listings (even for jobs where a PE would be completely irrelevant). My employer pays out a $1,000 bonus for getting a PE (it's mostly intended for our studies engineers, but I could do it too), so I guess there's that too. And Three-Phase that bad termination video is loving hilarious. Whoever made up those terminations should be fired, it's not really that difficult of a task. I tested thirty-three 5kV cables last week that were terminated by a kid who had never done them on his own before, and not a single one of them came even close to failing. Like, most of them were leaking less than a tenth of a microamp at 26 kVDC, which is really really good. Noctone fucked around with this message at 01:26 on Jul 13, 2013 |
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Jul 13, 2013 01:23
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PE is extremely important in construction and a few others areas, but not really used at all in manufacturing (which undergo different testing/certification processes). A licensed engineer's stamp on technical drawings is required for most commercial construction work. Also, in a lot of states, you're not legally allowed to call yourself an "engineer" if you're not a licensed PE, and companies have to have a licensed PE on the staff to advertise engineering services. Most civil engineering fields are in areas where PE is important, thus most CEs are PEs. The opposite is true for EE, where most work in fields where PE isn't required. I picked up my PE license a few years ago, but have yet to actually use it. It does seem to instantly garner a lot of professional respect, even if someone has never met you. grover fucked around with this message at 01:31 on Jul 13, 2013 |
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Jul 13, 2013 01:28
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Noctone posted:And Three-Phase that bad termination video is loving hilarious. Whoever made up those terminations should be fired, it's not really that difficult of a task. I tested thirty-three 5kV cables last week that were terminated by a kid who had never done them on his own before, and not a single one of them came even close to failing. Like, most of them were leaking less than a tenth of a microamp at 26 kVDC, which is really really good. I agree that it's really not that difficult. It's just basic electrical too usage (cutting cables and shield, hydraulic crimper, stripping insulation) and following instructions. The termination kits we bought had instructions that were very clear on how to perform the terminations correctly, what materials to use, and soforth. (The pictures were very useful, I'm not going to lie.) One of the big things I was concerned about on my install was if the terminations were botched, it would be difficult, time consuming, and very costly to fix. So considering the circumstances we took it step-by-step, worked together, and checked the work that was performed. It ultimately went really well. On that video, at fifteen seconds I see the terminations and thought "Wow... that's not right at all." Around 22 seconds is where my jaw dropped. Three-Phase fucked around with this message at 02:46 on Jul 13, 2013 |
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Jul 13, 2013 02:41
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Three-Phase posted:This will be neat for people who have never seen this: here are some examples of big The highest voltage circuit I've been around lately was a bit more than that, but only about 100 mA. On the other hand, it was a 100 mA beam current at 7 GeV or so. At that point, it's a beam of electrons in ultra-high vacuum. You know it's high voltage because it gives off X-rays when going around corners.
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Jul 13, 2013 18:53
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Today in the work simulator: Loss of steam pressure cause turbines to rapidly loose speed. Coolant Pumps trip off on Underfrequency. This in the middle of a previous double casualty of a single coolant pump failure and feed water leak. End result? A well executed casualty response stumbles, trips, and falls on its face. Loss of Coolant flow Reactor Scram, Turbine Generators still operating. Steam header pressure still fluctuating wildly. I got to experience this first hand and the simulator staff were baffled for about 10 minutes. Its fun watching MultimegaWatt jumps up, down, and shift sides like that and just knowing things are going horribly wrong.
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Jul 13, 2013 23:25
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Is the feedwater leak on the secondary coolant loop like in a PWR, or are you talking about a BWR where a leak means you have radioactive water dripping into a sump somewhere? Did you switch the coolant pumps to a secondary/emergency power feed? (I'm assuming these are probably several thousand horsepower water pumps from a MV feed.)
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Jul 14, 2013 00:19
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