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babyeatingpsychopath posted:They've got a website! McMaster-Carr is awesome. Grainger, too. Although I have found that there's a brick & mortar Grainger almost everywhere, so they've got that going for them. Does McMaster-Carr even exist in the real world? I don't know.
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Apr 22, 2013 15:05
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Bad Munki posted:Grainger is all right. But McMaster-Carr is and always will be the poo poo. They have a warehouse about the size of Jupiter in Elmhurst, Il. It's loving spectaculer.
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Apr 22, 2013 20:12
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Actually, thank you for mentioning that. It made me actually bother to look up their locations, and it looks like there's one in Cleveland, which is just a couple hours away and where all the other interesting suppliers I want to go visit are as well. 
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Apr 22, 2013 20:17
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There is one in the Newark area too, when I was working down there we used to get everything next-day even with economy shipping and occasionally if we ordered early enough in the day it'd show up same-day with economy shipping. Was pretty nice.
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Apr 22, 2013 20:47
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Lt Moose posted:I'm working on converting a vehicle to an EV and am looking for some sort of switch.. We have 2 plugs in the charging port, 120 or 240. Only one source will be plugged into the on-board vehicle charger at one time. However, the charger only has one input. We are looking for some sort of switch with 2 inputs and 1 output that can go between the charger and the grid power. I don't want to just parallel both charging cables since then when one is plugged in, the other will be live and it could be a potential safety issue. Possible simpler solution - does the onboard charger actually have different inlets depending on power source, or do the cords terminate back at the same point? If they connect to the charger in the same way and the charger just autosenses whether it's on 120 or 240, why not just make up a cheater cord that has a 5-15 plug going to the 240V receptacle of your choice? Then you only have the one charge cord to deal with, no switching needed. If 240V is available, you plug in with the appropriate connector, if not you use your cheater cord to plug into 120V. Either that or just go nuts and do a full implementation of SAE J1772
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Apr 22, 2013 20:49
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IOwnCalculus posted:Possible simpler solution - does the onboard charger actually have different inlets depending on power source, or do the cords terminate back at the same point? If they connect to the charger in the same way and the charger just autosenses whether it's on 120 or 240, why not just make up a cheater cord that has a 5-15 plug going to the 240V receptacle of your choice? Then you only have the one charge cord to deal with, no switching needed. If 240V is available, you plug in with the appropriate connector, if not you use your cheater cord to plug into 120V. That's actually a great idea and I think we will end up going that route. Funny you mention that, since someone just suggested that also today. The charger just autosenses, so we are going to use the cheater cord for when 120V is going to be used (rarely). J1772 is on the wishlist, however the main goal is to get the vehicle moving now, and then add some fancy features later. The nice thing is the charger partially supports the protocol, so there won't be too much custom hardware to make (hopefully at least).
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Apr 22, 2013 23:07
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kid sinister posted:edit: I'm pretty sure that old Pushmatic 2-pole breakers were like that with one phase on either side of the box, but that's all that come to mind... Correct. My breakers straddle a dividing bar with one bus bar on each side. Then the whole setup is repeated on the other side of the box, so there are actually four bus bars. I believe mine is new enough to have thermal and magnetic trip in the breakers... The really old ones were thermal only. Fun fact: with a SquareD, GE, etc panel you can turn the breaker off then pull or install it while the bus is live without turning off the main breaker. The Pushmatic breakers are screwed down to the bus bar. I did not attempt that installation with the main breaker live. Did I mention the little ON/OFF indicators like to get stuck in one position or the other without regard to the actual status of the breaker?
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Apr 27, 2013 03:25
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Im installing a whole house fan this weekend and need some guidance wiring it up. In my attic there is a regular 3-prong outlet connection that my HVAC unit is hooked up to. The fan I'm installing has a simple white/black/red coming from it. I'll need to go to the supplied hi/low switch, a purchased timer, and then into the power source. Can I just tap straight into the box that is supplying power to the outlet? Also, how does it need to be wired so I can use the hi/low switch and the timer I bought? Can I just use romex-type wire for all this?
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Apr 27, 2013 05:31
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FCKGW posted:Im installing a whole house fan this weekend and need some guidance wiring it up. If it's a 120V motor, then yes. Follow the wiring diagram for the switch and timer. If everything is in your attic, romex-type is fine.
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Apr 27, 2013 17:58
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Ender.uNF posted:Fun fact: with a SquareD, GE, etc panel you can turn the breaker off then pull or install it while the bus is live without turning off the main breaker. The Pushmatic breakers are screwed down to the bus bar. I did not attempt that installation with the main breaker live. You get yourself one of these and you'll be able to install screw in breakers live no problem, as long as you don't touch anything else inside of it.
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Apr 27, 2013 18:52
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Pufflekins posted:You get yourself one of these and you'll be able to install screw in breakers live no problem, as long as you don't touch anything else inside of it. Warnings: NOT insulated. Will NOT protect against electrical shock.  You can get insulated tools if you really want to. For a house or something, I just turn off the main. Other places? I'll use the insulated tools provided by the contractor. I don't do side jobs hot; it's not worth a few bucks to get myself killed if something bizarre happens, like a bird flies by and drops dead into the open panel you're working on. That happened to a guy I know, and it's the kind of stuff not really worth planning for.
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Apr 27, 2013 19:02
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Pufflekins posted:You get yourself one of these and you'll be able to install screw in breakers live no problem, as long as you don't touch anything else inside of it. I don't think so, Tim.
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Apr 28, 2013 01:01
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So I have a couple questions about wiring. I'm a student studying industrial maintenance and that included residential and commercial wiring courses, but for the life of me I can't remember some of this stuff. The project is supply electricity from a source to a pair out laying locations. Its a 240v panel that's fed straight from the pole. I need to supply power to a pavilion about 150 feet away, and to an area of enclosures for keeping large animals another 100 feet out beyond that. The pavilion will need 3 lights (most likely outdoor halogen spot lights, but could just be 100 watt equivalent CFLs, and will have two pairs of receptacles. The enclosure area beyond will have 6-8 floodlights but no receptacles. The expected things to be plugged into the pavilion would be crock pots and coffee makers, maybe a boombox or small stereo system (100 watts give or take). The initial plan was to run XHHN or THWN from the barn where the panel is, across a road on the property (on a pair of electrical poles that already have the needed bits on the pole from a previous elevated cable) and to an outbuilding (that has the other cable already feeding a panel), then burying it the rest of the way to the pavilion, and the enclosures. I had planned on two separate circuits both with 30A breakers at the main panel, but since the panel is 240 and I need 120 on the feeder circuits, I'm not 100% certain how to accomplish this safely. The outbuilding has a feeder panel that I thought was wired funny when I first looked at it, but after digging through my text books, I'm not so certain it was hanky. The main panel had Hot, Neutral and Ground wired as you would expect, but the feeder panel had the neutral tied to ground. The breakers would pop the moment something was plugged into it and I thought that was because of the wire in the panel. (there wasn't a GFCI in the building all though there should be.) It wasn't until I had separated out the neutrals off the ground and added a second circuit breaker and had some CFLs fizzle out that I realized the panel was 240 and feeding too much juice to the light bulbs. I wired it back up the way I found it, but kept the 2nd circuit breaker (feeding 1 receptacle and the other feeding the lights) and the breakers stopped being dumb. When I measure the voltage (which I probably should have done initially instead of just checking continuity so I knew what wire and bus bar was what) I was getting 120 like I should have. The questions: Why was I getting 120 on the panel? Shouldn't the neutral being wired to the ground in that panel cause ground faults when something completed the circuit? Is there a better solution to running elevated cable and then burying the rest (in underground conduit)? If I need 120 at the pavilion and enclosures, will I need to tie the neutrals to ground in the main panel? If not, do I need a new feeder panel? What would be the ideal circuit breakers for the two applications? I was thinking 15A for the enclosures and 30A for the Pavilion? Would I need to increase the size of the main breaker on the main panel? (200A main breaker on the panel, with 15-30A breakers feeding lights, receptacles, 2 industrial freezers, 1 industrial fridge and 2 residential style fridges and freezers) Is 14-2 sufficient or would I need to bump the size up to 12-2? Are there any questions I should have asked or information I should have provided? Disclaimer: The person I'm doing work for knows I'm only a student and not a licensed electrician so there isn't any deception on my part. I want to make sure I'm doing it right and I do a good job on it since its all experience to help me when I eventually graduate and hit the field. 
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Apr 28, 2013 03:46
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babyeatingpsychopath posted:Warnings: NOT insulated. Will NOT protect against electrical shock. The additional concern I have is that its got an uninsulated metal shaft. Even for low voltage live work you get tools that are insulated almost all the way to the tip. It makes it easy to accidentally shock yourself, or short-circuit the panel from phase to ground if the shaft touches the panel and bus simultaneously. Best case you get a shower of sparks and damage the panel, worst case may involved going to the hospital for (likely minor) burns depending on the protection on the main breaker/fuses. (For a commercial or industrial panel fed from a much larger transformer or unit sub, it could result in much more serious burns.)
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Apr 28, 2013 04:49
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Kasan posted:Are there any questions I should have asked or information I should have provided? Please draw a picture. Get in the code book, look at the sections on feeders, branch circuits (outdoor), burial depths or overhead clearances, grounding, and whatever conduit you want to use. Basically sections 210, 220, 225, 250, 310. Maybe stop on over in 240 for a bit, too. I see a WHOLE BUNCH wrong/scary here, but this is basically "design a service for me" and reads close to the section of the Master Electrician's exam that counts for 1/3 the points, so not something easy or simple.
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Apr 28, 2013 06:33
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Kasan posted:So I have a couple questions about wiring. I'm a student studying industrial maintenance and that included residential and commercial wiring courses, but for the life of me I can't remember some of this stuff. How about a diagram of wiring paths and panels? Your description sucks.
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Apr 28, 2013 19:03
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I'm not trying to be a dick, but I have absolutely no idea where to begin on this. A diagram would be a wonderful start.
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Apr 28, 2013 21:07
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I am terrible at anything requiring drawing but in theory this should be understandable. The black line is suspended from the far left building to the next building over. The red lines will probably be buried to save on headaches. Everything should be 120V outside of the main panel. Is this helpful or more confusing? quote:I see a WHOLE BUNCH wrong/scary here, but this is basically "design a service for me" and reads close to the section of the Master Electrician's exam that counts for 1/3 the points, so not something easy or simple. That's why I asked. The electrical classes I took hit the highlights more than anything. I kept my textbooks as reference in the event I needed to wire something around the house. Theoretically the service is already designed (albeit ugly and in need of work). No actual work will be preformed until I know it won't kill somebody or something in the process. I know enough to know I don't know enough to tackle it alone so I plan on getting more experienced help at install time.
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Apr 29, 2013 22:49
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Ok. So let's look at this diagram and see if we can make sense of it. From left to right, you have two enclosures, then a pavilion, then an existing building which we're going to ignore, then your service location. You are going to go overhead from the enclosures, to the pavilion, then underground to the service. The pavilion is going to have two outlets and three lights. We're going to call the two outlets "four receptacles" since you expect crock pots. The lights we're going to call 100W each. So that's 180VA per receptacle plus 100VA for each light, for a total of 1020VA / 120V = 8.5A. A 15A circuit should be fine, wire size to be determined by distance, but I'd go with 12s probably. The enclosures get their own lights, too. 600VA / 120V = 5A. Another 15A circuit, also on 12s because of distance. Now you can't run THHN overhead, as far as I can tell, so you get to put a junction box on the pavilion and switch over to triplex, messenger-supported SE, or something like that. Triplex isn't sold in smaller than #8, I think. You can get SE or USE in 12 or 10, pretty sure. Now that that's settled, explain what's going on in that ignored building succinctly in its own paragraph.
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Apr 30, 2013 01:52
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babyeatingpsychopath posted:You are going to go overhead from the enclosures, to the pavilion, then underground to the service. Other way around, Its overhead from the service to the existing build, then underground everywhere else. The ignored building is receiving 240V overhead via a 12-2 UF-B W/G cable being fed into a feeder panel. The feeder panel contains a 2 circuit breaker bus bar (I might be using wrong terms, it supports 2 breaker pairs). A 30A breaker is feeding 1 outlet (2 receptacles) with a foot of standard 14-2 romex. A 15A breaker is feeding 2 lights in series (with 22.5 watt CFLs if it matters). The Panel is wired with neutrals to ground on both breakers and is providing 120V RMS according to my meter when I checked it. I actually have a photograph of the interior of that panel (in pretty high resolution) that I can post tomorrow if needed. The service is a hot mess and I'd need to go back onsite to study it in order to actually give anything useful beyond the wiring relating to the current outbuilding and proposed setup. We've got about a half mile of underground electrical conduit to cover 100ish yards so I think we're good on that. I have outdoor weatherized lighting, receptacles and a pair of weatherized panels to play with. I do not have enough cable (of any type really) to do anything with. The cable is really the biggest issue in terms of getting purchased. Everything else comes down to design and making sure there aren't any gross code violations that will result in fire or electrical shock to either the staff or the animals kept in the enclosures. The site owner is big on cutting corners, but electrically ignorant and leaving decisions on that up to me. As I said in the previous post, I know enough to know that I don't know enough and a pair of text books (Modern Residential/Commercial Wiring - Harvey N. Holzman (2011 NEC)) and the out of date copy of the NEC I have (also 2011) will only get me so far and isn't a fair replacement for practical OTJ experience. Edit: There are actually 19 enclosures on that side, I only need lighting in 4 (maybe 5) places. For mathing just assume I'm under budgeting myself and really need 8, so call it 7 amps just on that line alone. Kasan fucked around with this message at 05:04 on May 1, 2013 |
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May 1, 2013 05:01
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Ok. So the 12/2/g UF going overhead is possibly legal. The bare wire in that case would be attached to the neutral bar, and there would be a ground rod installed close by with a ground wire run to the ground bar in the panel. There will be no bond between the neutral and the ground, in that case. This means you just have a 12/3, really, two hots and a neutral, with no ground provided from the service point. This was legal back in the day, and as long as it's still wired like that and you're not doing anything to it, you're fine. Check section 250 (grounding) and 225 (Outside branch circuits and feeders). Feeding #14 romex with a 30A breaker is definitely wrong, and has never been right. That should be a 15A max, and if there's only outlet, it should be rated at the breaker size. Technically, enclosures for animals have a whole host of special wiring conditions. Look at article 547. As long as it's just lights, I don't think you have to worry too much about "equipotential planes" and whatnot. The 2011 NEC is the most recent version. It's updated every 3 years, so around October this year, the 2014 will be released, with it beginning to be adopted in many locales by mid- to late-2014. Do check out the sections I mentioned in my first reply to you.
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May 1, 2013 16:15
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babyeatingpsychopath posted:Feeding #14 romex with a 30A breaker is definitely wrong, and has never been right. That should be a 15A max, and if there's only outlet, it should be rated at the breaker size. I see where I was confused on the #14 romex and the 30am circuit. 240.5(B)(2) listed fixures at 30A for #14, but 240.3(D)(3) lists it at 15A for #14 copper. Whoops. I'll change that breaker when I get out there next (There isn't anything other than a cash register/laptop ever plugged into it (supposedly)) 547 was a fun read and told me I could do a few things I didn't know I could so long as I have the right panel box. ------ So If I am reading the code correctly, I need to size the pavilion for 840VA / 120V (15A breaker should be enough I think), and the enclosures for 15A as well. Hanging the UF appears to be ok in my case due to how the barn is wired and classified in the code, and burying it the rest of the way is also going to be kosher. As of writing I'm still digging through the section on grounding and bonding looking for the relevant sections for an aluminium pavilion and chain link fences that use wooden posts instead of metal.
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May 1, 2013 19:28
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Pufflekins posted:You get yourself one of these and you'll be able to install screw in breakers live no problem, as long as you don't touch anything else inside of it. I will not be attempting this manuver, and will continue to turn off the 200A main before working in the panel.
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May 1, 2013 22:43
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Kasan posted:So If I am reading the code correctly, I need to size the pavilion for 840VA / 120V (15A breaker should be enough I think), and the enclosures for 15A as well. Hanging the UF appears to be ok in my case due to how the barn is wired and classified in the code, and burying it the rest of the way is also going to be kosher. As of writing I'm still digging through the section on grounding and bonding looking for the relevant sections for an aluminium pavilion and chain link fences that use wooden posts instead of metal. Metal fences and siding are outside the scope of NEC (see 250.116), but it probably wouldn't hurt. Not sure about the best way to do it, but you won't find it in NEC. NESC, maybe. You can't hang UF cable outdoors unless it's UV-rated and supported by a properly-sized messenger wire (340.12, 396). Normally exposed UF should be inside conduit like this. Down to Carabus fucked around with this message at 05:23 on May 4, 2013 |
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May 2, 2013 20:46
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I've got a circuit in one of our retail stores that is baffling me. First I was called out to investigate why half the fluorescent lights in the store were blinking but wouldn't turn on. It turns out that their shared neutral with the exit lights in one box had melted. As best as I can figure, it looked like a loose twist junction judging from the nut melting too. So I replaced those 3 neutral wires that joined there back to their respective boxes and viola, the lights are all working now! Now that I did that however, another circuit is acting screwy. It's a one box circuit and now it tests at 150V with my multimeter hot to neutral. Hot to ground it tests at 120V, so somehow it's picking up another 30V through its neutral. Can anyone help me with this? I'm not terribly familiar with 3 phase power. I do know that the problem circuit shares that same neutral with the lights. I replaced that white wire all the way down the conduit to a box with all the mentioned neutrals in it. That was the only neutral bundle I untwisted in that box, but there are 2 other neutral bundles in that box.
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May 2, 2013 21:34
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kid sinister posted:Now that I did that however, another circuit is acting screwy. It's a one box circuit and now it tests at 150V with my multimeter hot to neutral. Hot to ground it tests at 120V, so somehow it's picking up another 30V through its neutral.
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May 2, 2013 22:24
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Carabus posted:Another loose neutral? Check the connections or call your power company. Floating neutrals in three-phase systems can damage equipment, shock etc. Bingo, it was another loose neutral. That's what the electrician said anyway. What's weird is that he said it was at the panel... Some neutrals weren't screwed down fully on the busbar. That doesn't make sense to me since that problem circuit was sharing a neutral with some other circuits and those other circuits sharing that neutral all tested fine. I'm chalking this one up to a gremlin.
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May 3, 2013 23:00
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 In the "electrical failures" category, this wonderful photo of a device got forwarded to me today. It would be more believable if it only had one hot cam, but I can't help but think that someone has done this for real.
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May 4, 2013 19:44
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What are those plugs on the end for?
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May 4, 2013 19:56
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kid sinister posted:What are those plugs on the end for? 
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May 4, 2013 20:04
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grover posted:Those are connectors for large single-conductors with colors codes for 3-phase 208V power. Kinda funny they'd pretend to plug in a powerstrip. I like this one better: Hey, I remember making one of those. I even used the label maker to mark it as a "NIC Stress Tester" and hung it on the wall. No clue if anyone ever decided to try it, but I did actually hook it up pairwise to the hot/neutral and the one time I plugged it into an old card, it didn't smoke, but the entire card did go electrically hot.
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May 4, 2013 20:06
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grover posted:Those are connectors for 3-phase 208V power. For high powered connections. Kinda funny they'd pretend to plug in a powerstrip. I like this one, too: One of those came up in the Segakiller thread ages ago.
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May 4, 2013 21:20
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kid sinister posted:What are those plugs on the end for? Those are cam-lock connectors, typically seen on welding cable. The relative size of those looks like they'd be on a 100A cable. I made one of those LAN killers, too. All the tips were hot, all the rings were neutral. It kept moving from its spot on my shelf, but nobody admitted to ever using it in anger.
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May 5, 2013 02:48
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grover posted:Those are connectors for 3-phase 208V power. For high powered connections. Kinda funny they'd pretend to plug in a powerstrip. I like this one, too: babyeatingpsychopath posted:Those are cam-lock connectors, typically seen on welding cable. The relative size of those looks like they'd be on a 100A cable. To add on to both of these posts, cam-locks are primarily used for temporary three-phase power feeds. Probably the most common application I see is to connect a load bank to a generator. We also use them quite regularly at work to feed 480 or 208 to our breaker test sets.
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May 5, 2013 03:33
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Noctone posted:To add on to both of these posts, cam-locks are primarily used for temporary three-phase power feeds. Probably the most common application I see is to connect a load bank to a generator. We also use them quite regularly at work to feed 480 or 208 to our breaker test sets. Those cams in particular are the ones we use for temporary connection to a 400A company switch, something like this. The other end goes to a distro that breaks it out into 120v 20A circuits or to dimmers/hydraulic pumps/automation controllers/etc. 
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May 5, 2013 07:19
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You know what's fun? When some idiot runs those cables across a road on campus when doing a concert setup, uses proper protective ramps/stuff, but crosses the cables. And then a bus drives across it in just the wrong spot. That was a hell of a bang when the insulation crushed to the point that two phases shorted together  blew up around 3 feet of cable. IIRC it's still hanging on the wall in the A/V club's office as a warning to newbies.
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May 5, 2013 14:09
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babyeatingpsychopath posted:nobody admitted to ever using it in anger. "That NAS was coming right for us! It was either it or us."
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May 5, 2013 22:13
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What would actually be cool would be to embed a PoE module inside the 120V plug, I imagine someone could cram the needed parts in a space like that (I guess the hardest part would be the transformer, but then, Apple does it with their USB power bricks.) Then you could really freak people out with a completely usable--and even useful--120V->ethernet patch cable.
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May 5, 2013 23:24
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Noctone posted:To add on to both of these posts, cam-locks are primarily used for temporary three-phase power feeds. Probably the most common application I see is to connect a load bank to a generator. We also use them quite regularly at work to feed 480 or 208 to our breaker test sets.
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May 6, 2013 00:51
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Bad Munki posted:What would actually be cool would be to embed a PoE module inside the 120V plug, I imagine someone could cram the needed parts in a space like that (I guess the hardest part would be the transformer, but then, Apple does it with their USB power bricks.) Then you could really freak people out with a completely usable--and even useful--120V->ethernet patch cable. They have wallwarts that do this, but they are pretty bulky since they need to have 2 RJ45 ports. The thing about PoE is that it has to carry data too. That means that your PoE injector has to have an incoming LAN port and an outgoing PoE port. USB won out because it included power from the start and didn't have IP addressing problems to worry about. Later, USB mini and micro connectors came out that were small enough to put on any device.
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May 6, 2013 01:13
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